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Comizzoli, P., D. Wildt y B. Pukazhenthi. "354 POOR EMBRYO DEVELOPMENT AFTER ICSI WITH DOMESTIC CAT TESTICULAR SPERM IS OVERCOME BY CENTROSOME AND MIDPIECE REPLACEMENT". Reproduction, Fertility and Development 18, n.º 2 (2006): 284. http://dx.doi.org/10.1071/rdv18n2ab354.
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Testicular sperm from the cat can be used via intracytoplasmic sperm injections (ICSI) to produce embryos in vitro, but the proportion of morulae and blastocysts is less than that obtained using ejaculated sperm. Compromised embryo development has been linked to the inability of the cat testicular sperm centrosome to form a normal sperm aster during the first cell cycle post-ICSI. The aim of the present study was to improve embryo development after ICSI with a testicular spermatozoon by centrosome/midpiece replacement from an ejaculated spermatozoon. Sperm suspensions used for ICSI (fresh testicular sperm from one adult testis vs. frozen-thawed sperm from one ejaculate in each replicate; four replicates) were sonicated for 3 s at setting 3 using a 60 Sonic Dismembrator (Fisher Scientific, Pittsburgh, PA, USA) to separate heads from centrosome/midpieces. Control immunostaining with monoclonal centrin antibodies revealed that centrosomes were attached to midpieces and were separated from sperm heads after sonication. A single sperm head (testicular, Th; ejaculated, Eh) was carefully positioned proximal to a single centrosome/midpiece (testicular, Tc; ejaculated, Ec) before injection into an oocyte with a visible polar body (in each replicate, n = 18 oocytes injected with each ThEc, EhEc, EhTc, or ThTc combination; four replicates). Injected oocytes then were activated with 7% ethanol and cultured in vitro in Ham's F10 (38.5�C, 5% CO2 in air). Percentages of first cleavages were recorded from 20 to 32 h post-activation (hpa). Nuclear status of uncleaved oocytes was evaluated at 48 hpa, and embryo development was assessed after 7 days of in vitro culture. Values were expressed as mean � standard deviation and analyzed by ANOVA. None of the uncleaved oocytes were activated. Percentages of cleaved oocytes (relative to the total number of injected oocytes) were not different (range, 61-65%; P > 0.05) among combinations of sperm heads and centrosome/midpieces. The mean times of the first cleavage, however, were earlier (P < 0.05) after combinations with ejaculated centrosome/midpieces (ThEc, 25.1 � 1.1 h; EhEc, 25.0 � 0.9 h) than with testicular centrosome/midpieces (EhTc, 29.2 � 0.8 h; ThTc, 29.3 � 1.2 h). Percentages of morulae produced were higher (P < 0.05) after combinations with ejaculated centrosome/midpieces (ThEc, 15.3 � 2.7%; EhEc, 16.7 � 2.1%) than with testicular centrosome/midpieces (EhTc, 8.3 � 3.1%; ThTc, 6.9 � 2.2%). Likewise, percentages of blastocysts were higher (P < 0.05) after combinations with ejaculated centrosome/midpieces (ThEc, 12.5 � 3.0%; EhEc, 13.9 � 2.8%) than with testicular centrosome/midpieces (EhTc, 5.6 � 3.3%; ThTc, 6.9 � 2.9%). These results demonstrated that: (1) kinetics of the first cell cycle and the success of embryonic development were determined by centrosome/midpiece source; and (2) poor developmental potential of domestic cat testicular sperm could be circumvented by centrosome/midpiece replacement from an ejaculated spermatozoon.
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Vladić, Tomislav y Erik Petersson. "Artificially selected human sperm morphology after swim-up processing". Canadian Journal of Zoology 90, n.º 10 (octubre de 2012): 1207–14. http://dx.doi.org/10.1139/z2012-088.
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The swim-up technique is a clinical practice used to select highly motile sperm cells from patient ejaculates to use in assisted fertilization. The aim of this study was to investigate whether the length of different sperm-cell components is related to gamete function. Thus, we explored whether swim-up technique selects for longer sperm cells than mean sperm cells from unprocessed ejaculates. Sperm midpiece, tail endpiece, and total length were measured before and after the swim-up selection by means of contrast-phase and electron microscopy. Correlations between sperm dimensions, sperm motility, and sperm concentration were also investigated. Swim-up selected cells with longer midpiece compared with the unprocessed fractions (5.8 μm (CI 5.52–6.16 μm) vs. 5.3 μm (CI 4.97–5.61 μm), p < 0.05) and shorter tail endpiece (7.8 μm (CI 7.11–8.44 μm) vs. 8.5 μm (CI 7.81–9.14 μm), p < 0.05 after meta-analysis), whereas no effect of swim-up selection was detected on the total sperm cell length. Individuals producing high sperm concentrations had longer sperm midpiece than had men producing lower sperm concentrations. It is concluded that short sperm flagellar tips with long midpieces may be used as biomarkers in infertility therapy.
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Knief, Ulrich, Wolfgang Forstmeier, Bart Kempenaers y Jochen B. W. Wolf. "A sex chromosome inversion is associated with copy number variation of mitochondrial DNA in zebra finch sperm". Royal Society Open Science 8, n.º 9 (septiembre de 2021): 211025. http://dx.doi.org/10.1098/rsos.211025.
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The propulsion of sperm cells via movement of the flagellum is of vital importance for successful fertilization. While the exact mechanism of energy production for this movement varies between species, in avian species energy is thought to come predominantly from the mitochondria located in the sperm midpiece. Larger midpieces may contain more mitochondria, which should enhance the energetic capacity and possibly promote mobility. Due to an inversion polymorphism on their sex chromosome TguZ , zebra finches ( Taeniopygia guttata castanotis ) exhibit large within-species variation in sperm midpiece length, and those sperm with the longest midpieces swim the fastest. Here, we test through quantitative real-time PCR in zebra finch ejaculates whether the inversion genotype has an effect on the copy number of mitochondrial DNA (mtDNA). We find that zebra finches carrying the derived allele (correlated with longer sperm midpieces) have more copies of the mtDNA in their ejaculates than those homozygous for the ancestral allele (shorter midpieces). We suggest downstream effects of mtDNA copy number variation on the rate of adenosine triphosphate production, which in turn may influence sperm swimming speed and fertilization success. Central components of gamete energy metabolism may thus be the proximate cause for a fitness-relevant genetic polymorphism, stabilizing a megabase-scale inversion at an intermediate allele frequency in the wild.
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Tilney, L. G. y S. Inoué. "Flagellar gyration and midpiece rotation during extension of the acrosomal process of Thyone sperm: how and why this occurs." Journal of Cell Biology 104, n.º 3 (1 de marzo de 1987): 407–15. http://dx.doi.org/10.1083/jcb.104.3.407.
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The midpiece of Thyone sperm contains a large mitochondrion and a centriolar pair. Associated with one of the pair, i.e., the basal body of the flagellum, are satellite structures which apparently anchor the flagellar axoneme to the mitochondrion and to the plasma membrane covering the midpiece. Immediately before and as the acrosomal process elongates, the flagellum and the midpiece begin to rotate at 1-2 rotations per second even though the head of the sperm, by being firmly attached on its lateral surfaces to the coverslip, does not rotate at all. This rotation is not observed in the absence of flagellar beating whose frequency is much greater than that of its gyration. To understand how the midpiece rotates relative to the sperm head, it is first necessary to realize that in Thyone the flagellar axoneme projects at an acute angle to the principal axis of the sperm and is bent towards one side of this axis. Thus movement of the flagellum induces the sperm to tumble or yaw in solution. If the head is stuck, the midpiece will rotate because all that connects the sperm head to the midpiece is the plasma membrane, a liquid-like layer. A finger-like projection extends from the proximal centriole into an indentation in the basal end of the nucleus. In contrast to the asymmetry of the flagellum, this indentation is situated exactly on the principal axis of the sperm and, along with the finger-like projection, acts as a biological bearing to maintain the orderly rotation of the midpiece. The biological purpose of flagellar gyration during fertilization is discussed.
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Bennison, Clair, Nicola Hemmings, Lola Brookes, Jon Slate y Tim Birkhead. "Sperm morphology, adenosine triphosphate (ATP) concentration and swimming velocity: unexpected relationships in a passerine bird". Proceedings of the Royal Society B: Biological Sciences 283, n.º 1837 (31 de agosto de 2016): 20161558. http://dx.doi.org/10.1098/rspb.2016.1558.
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The relationship between sperm energetics and sperm function is poorly known, but is central to our understanding of the evolution of sperm traits. The aim of this study was to examine how sperm morphology and ATP content affect sperm swimming velocity in the zebra finch Taeniopygia guttata . We exploited the high inter-male variation in this species and created extra experimental power by increasing the number of individuals with very long or short sperm through artificial selection. We found a pronounced quadratic relationship between total sperm length and swimming velocity, with velocity increasing with length up to a point, but declining in the very longest sperm. We also found an unexpected negative association between midpiece length and ATP content: sperm with a short midpiece generally contained the highest concentration of ATP. Low intracellular ATP is therefore unlikely to explain reduced swimming velocity among the very longest sperm (which tend to have a shorter midpiece).
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Malo, Aurelio F., Montserrat Gomendio, Julian Garde, Barbara Lang-Lenton, Ana J. Soler y Eduardo R. S. Roldan. "Sperm design and sperm function". Biology Letters 2, n.º 2 (23 de febrero de 2006): 246–49. http://dx.doi.org/10.1098/rsbl.2006.0449.
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Spermatozoa vary enormously in their form and dimensions, both between and within species, yet how this variation translates into fertilizing efficiency is not known. Sperm swimming velocity is a key determinant of male fertilization success, but previous efforts to identity which sperm phenotypic traits are associated with swimming velocity have been unsuccessful. Here, we examine the relationship between the size of several sperm components and sperm swimming velocity in natural populations of red deer ( Cervus elaphus hispanicus ) where selective pressures to enhance male reproductive success are expected to be strong. Our results show that there is little within-male and considerable between-male variation in sperm dimensions. Spermatozoa with longer midpieces swim more slowly, a finding which does not support the hypothesis that the size of the midpiece determines the amount of energy which is translated into swimming speed. In contrast, spermatozoa with elongated heads, and those in which the relative length of the rest of the flagellum is longer, swim faster. Thus, the hydrodynamic shape of the head and the forces generated by the relative size of the rest of the flagellum seem to be the key determinants of sperm swimming velocity.
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A..S..Abood, S. A. Hatif And. "Rams Infertility and Sperms Mitochondrial Genome Defect". Al-Qadisiyah Journal of Veterinary Medicine Sciences 10, n.º 2 (28 de diciembre de 2011): 55. http://dx.doi.org/10.29079/vol10iss2art154.
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This study was included a collection of 24 semen samples from healthy rams in Baghdad Province, performed in Baghdad- college of veterinary medicine.S perms stained with fluorescent dye ( ethidium bromide ) and subjected to fluorescent microscopical examination used by UV- light to visualize the defect in the mitochondrial sheath covered the midpiece. The results give the abnormalities of mitochondrial midpiece (mt sheat), the sperms appeared in 6 types of defect, included a mixed defect in the same sample. The defect included 5 ( 20.8%) cases interrupted distribution of mt genome, 4 (16.6%) narrow, 10 (41.6%) thickness , 8 (33.3%)irregular , 7(29.16%) short and 2(8.3%) absent of midpiece . The aim of this study, determination the defect of a mitochondrial sheath of midpiece, inactivity, motility, low quality of sperm and the role of infertility in ram.
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Firman, Renée C. y Leigh W. Simmons. "Sperm midpiece length predicts sperm swimming velocity in house mice". Biology Letters 6, n.º 4 (10 de febrero de 2010): 513–16. http://dx.doi.org/10.1098/rsbl.2009.1027.
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Evolutionary biologists have argued that there should be a positive relationship between sperm size and sperm velocity, and that these traits influence a male's sperm competitiveness. However, comparative analyses investigating the evolutionary associations between sperm competition risk and sperm morphology have reported inconsistent patterns of association, and in vitro sperm competition experiments have further confused the issue; in some species, males with longer sperm achieve more competitive fertilization, while in other species males with shorter sperm have greater sperm competitiveness. Few investigations have attempted to address this problem. Here, we investigated the relationship between sperm morphology and sperm velocity in house mice ( Mus domesticus ). We conducted in vitro sperm velocity assays on males from established selection lines, and found that sperm midpiece size was the only phenotypic predictor of sperm swimming velocity.
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Cramer, Emily R. A., Eduardo Garcia-del-Rey, Lars Erik Johannessen, Terje Laskemoen, Gunnhild Marthinsen, Arild Johnsen y Jan T. Lifjeld. "Longer Sperm Swim More Slowly in the Canary Islands Chiffchaff". Cells 10, n.º 6 (31 de mayo de 2021): 1358. http://dx.doi.org/10.3390/cells10061358.
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Sperm swimming performance affects male fertilization success, particularly in species with high sperm competition. Understanding how sperm morphology impacts swimming performance is therefore important. Sperm swimming speed is hypothesized to increase with total sperm length, relative flagellum length (with the flagellum generating forward thrust), and relative midpiece length (as the midpiece contains the mitochondria). We tested these hypotheses and tested for divergence in sperm traits in five island populations of Canary Islands chiffchaff (Phylloscopus canariensis). We confirmed incipient mitochondrial DNA differentiation between Gran Canaria and the other islands. Sperm swimming speed correlated negatively with total sperm length, did not correlate with relative flagellum length, and correlated negatively with relative midpiece length (for Gran Canaria only). The proportion of motile cells increased with relative flagellum length on Gran Canaria only. Sperm morphology was similar across islands. We thus add to a growing number of studies on passerine birds that do not support sperm morphology–swimming speed hypotheses. We suggest that the swimming mechanics of passerine sperm are sufficiently different from mammalian sperm that predictions from mammalian hydrodynamic models should no longer be applied for this taxon. While both sperm morphology and sperm swimming speed are likely under selection in passerines, the relationship between them requires further elucidation.
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Lawrence, M., G. Mastromonaco, K. Goodrowe, R. M. Santymire, W. Waddell y A. I. Schulte-Hostedde. "The effects of inbreeding on sperm morphometry of captive-bred endangered mammals". Canadian Journal of Zoology 95, n.º 8 (agosto de 2017): 599–606. http://dx.doi.org/10.1139/cjz-2016-0291.
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Captive breeding is used for the conservation of endangered species, but inbreeding can result when a small number of founders are used to establish populations. Inbreeding can reduce the proportion of normal sperm in an ejaculate, but may also have effects on sperm size and shape (morphometry). We investigated the effects of inbreeding on sperm morphometry of black-footed ferrets (Mustela nigripes (Audubon and Bachman, 1851)) and red wolves (Canis rufus Audubon and Bachman, 1851) from captive breeding programs to determine if more inbred males produced sperm of poor quality (bulky head, small midpiece, short tail). We measured sperm head length, head width, midpiece length, midpiece width, and tail length on 10 sperm from each male of both species. A negative relationship between variation in sperm tail length and inbreeding coefficient (f) was found in black-footed ferret, suggesting that more inbred individuals will have reduced genetic and phenotypic variation. Analyses indicated a negative relationship between sperm head width and f and a positive relationship between sperm tail length and f in red wolf, suggesting that more inbred male red wolves could have faster sperm. These results indicate that inbreeding affects functionally important aspects of sperm morphometry, but that these effects may not be entirely negative.
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Steinberg, Eliana R., Adrián J. Sestelo, María B. Ceballos, Virginia Wagner, Ana M. Palermo y Marta D. Mudry. "Sperm Morphology in Neotropical Primates". Animals 9, n.º 10 (21 de octubre de 2019): 839. http://dx.doi.org/10.3390/ani9100839.
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The morphological and morphometric characterization of spermatozoa has been used as a taxonomic and phylogenetic tool for different species of mammals. We evaluated and compared the sperm morphometry of five neotropical primate species: Alouatta caraya, Ateles belzebuth and Ateles chamek of family Atelidae; and Cebus cay (=Sapajus cay) and Cebus nigritus (=Sapajus nigritus) of family Cebidae. After the collection of semen samples, the following parameters were measured on 100 spermatozoa from each specimen: Head Length, Head Width, Acrosome Length, Midpiece Length, Midpiece Width and Tail Length. Considering the available literature on sperm morphometry, we gathered data of 75 individuals, from 20 species, 8 genera and 2 families. These data were superimposed on a phylogeny to infer the possible direction of evolutionary changes. Narrower and shorter spermatozoa seem to be the ancestral form for Cebidae, with a trend toward wider and larger heads in derived groups. The spermatozoa of Atelidae may show an increase in total length and midpiece length. Sperm heads would have become narrower in the more derived groups of Ateles. Sperm length may increase in the more derived species in both families. Our results are discussed in the context of sperm competition and sexual selection.
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Immler, Simone, Alejandro Gonzalez-Voyer y Tim R. Birkhead. "Distinct evolutionary patterns of morphometric sperm traits in passerine birds". Proceedings of the Royal Society B: Biological Sciences 279, n.º 1745 (15 de agosto de 2012): 4174–82. http://dx.doi.org/10.1098/rspb.2012.1398.
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The striking diversity of sperm shape across the animal kingdom is still poorly understood. Postcopulatory sexual selection is an important factor driving the evolution of sperm size and shape. Interestingly, morphometric sperm traits, such as the length of the head, midpiece and flagellum, exhibit a strong positive phenotypic correlation across species. Here we used recently developed comparative methods to investigate how such phenotypic correlations between morphometric sperm traits may evolve. We compare allometric relationships and evolutionary trajectories of three morphometric sperm traits (length of head, midpiece and flagellum) in passerine birds. We show that these traits exhibit strong phenotypic correlations but that allometry varies across families. In addition, the evolutionary trajectories of the midpiece and flagellum are similar while the trajectory for head length differs. We discuss our findings in the light of three scenarios accounting for correlated trait evolution: (i) genetic correlation; (ii) concerted response to selection acting simultaneously on different traits; and (iii) phenotypic correlation between traits driven by mechanistic constraints owing to selection on sperm performance. Our results suggest that concerted response to selection is the most likely explanation for the phenotypic correlation between morphometric sperm traits.
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Olson, Gary E. y Virginia P. Winfrey. "Mitochondria-cytoskeleton interactions in the sperm midpiece". Journal of Structural Biology 103, n.º 1 (marzo de 1990): 13–22. http://dx.doi.org/10.1016/1047-8477(90)90081-m.
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Núñez-Martinez, I., J. M. Moran y F. J. Peña. "Identification of sperm morphometric subpopulations in the canine ejaculate: do they reflect different subpopulations in sperm chromatin integrity?" Zygote 15, n.º 3 (agosto de 2007): 257–66. http://dx.doi.org/10.1017/s0967199407004248.
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SummaryA statistical approach using sequentially principal component analysis (PCA) clustering and discriminant analysis was developed to disclose morphometric sperm subpopulations. In addition, we used a similar approach to disclose subpopulations of spermatozoa with different degrees of DNA fragmentation. It is widely accepted that sperm morphology is a strong indicator of semen quality and since the sperm head mainly comprises the sperm DNA, it has been proposed that subtle changes in sperm head morphology may be related to abnormal DNA content. Semen from four mongrel dogs (five replicates per dog) were used to investigate DNA quality by means of the sperm chromatin structure assay (SCSA), and for computerized sperm morphometry (ASMA). Each sperm head was measured for nine primary parameters: head area (A), head perimeter (P), head length (L), head width (W), acrosome area (%), midpiece width (w), midpiece area (a), distance (d) between the major axes of the head and midpiece, angle (θ) of divergence of the midpiece from the head axis; and four parameters of head shape: FUN1 (L/W), FUN2 (4π A/P2), FUN3 ((L – W)/(L + W)) and FUN 4 (π LW/4A). The data matrix consisted of 2361 observations, (morphometric analysis on individual spermatozoa) and 63 815 observations for the DNA integrity. The PCA analysis revealed five variables with Eigen values over 1, representing more than 79% of the cumulative variance. The morphometric data revealed five sperm subpopulations, while the DNA data gave six subpopulations of spermatozoa with different DNA integrity. Significant differences were found in the percentage of spermatozoa falling in each cluster among dogs (p < 0.05). Linear regression models including sperm head shape factors 2, 3 and 4 predicted the amount of denatured DNA within each individual spermatozoon (p < 0.001). We conclude that the ASMA analysis can be considered a powerful tool to improve the spermiogram.
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Makino, Nanae, Nozomi Sato, Eriko Takayama-Watanabe y Akihiko Watanabe. "Localization of sperm intracellular Ca2+ keeps fertilizability in the newt vas deferens". Reproduction 159, n.º 3 (marzo de 2020): 339–49. http://dx.doi.org/10.1530/rep-19-0252.
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Sperm intracellular Ca2+ is crucial for the induction of sperm-egg interaction, but little is known about the significance of Ca2+ maintenance prior to induction. In sperm of the newt Cynops pyrrhogaster, intracellular Ca2+ is localized to the midpiece during storage in the vas deferens, while extracellular Ca2+ is influxed in modified Steinberg’s salt solution to promote a spontaneous acrosome reaction related to the decline of sperm quality. In the present study, sperm from the vas deferens were loaded with the Ca2+ indicator Fluo8H, and changes in Ca2+ localization in modified Steinberg’s salt solution were examined. Calcium ions expanded from the cytoplasmic area of the midpiece to the entire tail in most sperm during a 1-h incubation and localized to the principal piece in some sperm within 24 h. Similar changes in Ca2+ localization were observed in reconstructed vas deferens solution that included ions and pH at equivalent levels to those in the vas deferens fluid. Sperm with Ca2+ localization in the entire tail or the principal piece weakened or lost responsiveness to sperm motility-initiating substances, which trigger sperm motility for fertilization, but responded to a trigger for acrosome reaction. The change in Ca2+ localization was delayed and transiently reversed by ethylene glycol tetraacetic acid or a mixture of Ca2+ channel blockers including Ni2+ and diltiazem. These results suggest that C. pyrrhogaster sperm localize intracellular Ca2+ to the midpiece through Ca2+ transport in the vas deferens to allow for responses to sperm motility-initiating substances.
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Immler, Simone y Tim R. Birkhead. "Sperm competition and sperm midpiece size: no consistent pattern in passerine birds". Proceedings of the Royal Society B: Biological Sciences 274, n.º 1609 (28 de noviembre de 2006): 561–68. http://dx.doi.org/10.1098/rspb.2006.3752.
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Sperm competition is thought to be a major force driving the evolution of sperm shape and function. However, previous studies investigating the relationship between the risk of sperm competition and sperm morphometry revealed inconclusive results and marked differences between taxonomic groups. In a comparative study of two families of passerines (Fringillidae and Sylviidae) and also across species belonging to different passerine families, we investigated the relative importance of the phylogenetic background on the relationship between sperm morphometry and the risk of sperm competition. The risk of sperm competition was inferred from relative testis mass as an indicator of investment in sperm production. We found: (i) a significant positive association between both midpiece length and flagellum length and relative testis mass in the Fringillidae, (ii) a significant negative association between sperm trait dimensions and relative testis mass in the Sylviidae, and (iii) no association across all species. Despite the striking difference in the patterns shown by the Sylviidae and the Fringillidae, the relationship between midpiece length and flagellum length was positive in both families and across all species with positive allometry. Reasons for the differences and similarities between passerine families are discussed.
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Anderson, M. J., J. Nyholt y A. F. Dixson. "Sperm competition and the evolution of sperm midpiece volume in mammals". Journal of Zoology 267, n.º 02 (13 de octubre de 2005): 135. http://dx.doi.org/10.1017/s0952836905007284.
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Zhang, Ying, Young Ou, Min Cheng, Habib Shojaei Saadi, Jacob C. Thundathil y Frans A. van der Hoorn. "KLC3 is involved in sperm tail midpiece formation and sperm function". Developmental Biology 366, n.º 2 (junio de 2012): 101–10. http://dx.doi.org/10.1016/j.ydbio.2012.04.026.
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Toure, Aminata, Baptiste Rode, Gary R. Hunnicutt, Denise Escalier y Gérard Gacon. "Septins at the annulus of mammalian sperm". Biological Chemistry 392, n.º 8-9 (1 de agosto de 2011): 799–803. http://dx.doi.org/10.1515/bc.2011.074.
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Abstract The annulus is an electron-dense ring structure connecting the midpiece and the principal piece of the mammalian sperm flagellum. Proteins from the septin family have been shown to localize to the annulus. A septin complex is assembled early in spermiogenesis with the cochaperone DNAJB13 and, in mature sperm, associates with Testis Anion Transporter 1; SLC26A8 (Tat1), a transmembrane protein of the SLC26 family. Studies in mice have shown that the annulus acts as a barrier to protein diffusion and controls correct organization of the midpiece. Consistent with these findings, absence of the annulus is associated with flagellum differentiation defects and asthenozoospermia in humans.
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Souza, C. E. A., A. A. Moura, A. C. Lima-Souza y G. J. Killian. "Binding patterns of seminal plasma plasma proteins on bovine epididymal and ejaculated sperm membrane". Arquivo Brasileiro de Medicina Veterinária e Zootecnia 63, n.º 3 (junio de 2011): 535–43. http://dx.doi.org/10.1590/s0102-09352011000300001.
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The present study was designed to investigate the topographical distribution of seminal plasma (SP) proteins on epididymal and ejaculated bovine sperm. Using immunocytochemistry and confocal microscopy the binding patterns of bovine SP proteins BSP-A3, albumin, transferrin, prostaglandin D-synthase (PGDS) and nucleobindin in ejaculated and cauda epididymal sperm from adult bulls were evaluated. Experiments were performed using sperm from 5 males. Data showed a positive signal, only detected for anti-PGDS, in the acrosomal cap of epididymal and ejaculated sperm. In ejaculated sperm, a very weak signal for nucleobindin 2 in the midpiece and equatorial regions was detected, using the anti-rat nucleobindin. BSP-A3 was detected on all sperm regions studied, with a more evidenced signal in acrosome and midpiece. However, no binding was detected for albumin or transferrin in neither epididymal nor ejaculated sperm. In conclusion, PGDS, BSP-A3 and nucleobindin interact directly with bovine sperm, with specific topographic distribution. These findings may add to the knowledge of how these proteins modulate sperm functions, thus providing fundamental support for studies designed to evaluate how they influence sperm functions.
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Molnár, A., P. Sarlós, G. Fáncsi, J. Rátky, Sz Nagy y A. Kovács. "A sperm tail defect associated with infertility in a goat — Case report". Acta Veterinaria Hungarica 49, n.º 3 (agosto de 2001): 341–48. http://dx.doi.org/10.1556/004.49.2001.3.11.
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Semen of an infertile Dutch White (Saanenthal) goat buck was examined. Light and electron microscopic examinations showed aberrations of the sperm tails resembling the so-called Dag or Dag-like defects described in several cattle breeds. Ejaculated semen showed that virtually all of the cells had strongly coiled or broken tails, or fractured midpieces. Ultrastructural investigations by transmission electron microscopy (TEM) showed uneven distribution of the mitochondria in the midpiece. Coiled tails were encapsulated by a common membrane, and dislocated axial fibres and different membranous structures were also present. The ultrastructural characteristics of the defective sperm tails, the missing parts of the axial fibre bundle and the misalignment of the mitochondria indicate that this first case reported in goat is similar to the Dag-like defect in cattle.
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Kaldis, P., M. Stolz, M. Wyss, E. Zanolla, B. Rothen-Rutishauser, T. Vorherr y T. Wallimann. "Identification of two distinctly localized mitochondrial creatine kinase isoenzymes in spermatozoa". Journal of Cell Science 109, n.º 8 (1 de agosto de 1996): 2079–88. http://dx.doi.org/10.1242/jcs.109.8.2079.
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The creatine kinase (CK) isoenzyme system is essential for motility in rooster and sea urchin sperm. In the present study, biochemical characterization as well as immunofluorescence and confocal laser microscopy with highly specific antibodies against various chicken CK isoenzymes revealed that cytosolic brain-type CK isoenzyme (B-CK) is the only CK isoenzyme in rooster seminal plasma, while three isoenzymes, cytosolic B-CK, sarcomeric mitochondrial CK (Mib-CK), and a variant of ubiquitous Mi-CK (‘Mia-CK variant’), are found in rooster spermatozoa. These three isoenzymes are localized in different regions of the sperm cell. B-CK and Mib-CK were localized along the entire sperm tail and in the mitochondria-rich midpiece, respectively. The ‘Mia-CK variant’, on the other hand, was found predominantly at the head-midpiece boundary, in a non-uniform manner in the midpiece itself and, surprisingly, at the distal end of the sperm tail as well as at the acrosome. Several lines of evidence show that the ‘Mia-CK variant’ shares some characteristics with purified Mia-CK from chicken brain, but also displays distinctive features. This is the first evidence for two different Mi-CK isoenzymes occurring in one cell and, additionally, for the co-expression of Mib-CK and cytosolic brain-type B-CK in the same cell. The relevance of these findings for sperm physiology and energetics is discussed.
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Soldatenko, E. V., A. B. Shatrov, A. A. Petrov y T. Ya Sitnikova. "Sperm ultrastructure in Culmenella rezvoji (Lindholm, 1929) (Gastropoda: Hygrophila)". Ruthenica, Russian Malacological Journal 29, n.º 3 (17 de junio de 2019): 161–70. http://dx.doi.org/10.35885/ruthenica.2019.29(3).4.
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The taxonomic position of the genus within Hygrophila remains uncertain. The spermatozoa of , a species from the Far East of Russia, were examined using a combination of light, scanning and transmission electron microscopy with the objective to assess the utility of sperm characters for clarifying the phylogenetic relationships of the genus. The spermatozoa of C. rezvoji are divided into four regions: head, midpiece, glycogen piece and endpiece. The head contains a slender, cone-shaped acrosome and a conical nucleus with a sinistrally coiled keel. The acrosome consists of an apical vesicle and a thick-walled pedestal with an electron lucent canal partially filled with a patchy electron-dense material. The midpiece contains the mitochondrial derivative that encloses apically three parallel glycogen-filled tracts (helices) positioned in such a way that in the sperm cross section two helices lie opposite each other and equidistant from the third helix. The surface of the sperm above one of the helices forms a high, narrow ridge; the ridges above the remaining two helices have a much lower profile. The boundary between the midpiece and glycogen piece is demarcated by a constriction (annulus) consisting of an anterior electron-dense ring and a posterior conical cylinder connected to the ring with thin filaments. The structure of spermatozoa in Culmenella is consistent with the general pattern of sperm morphology common to all studied species of Hygrophila, but the spermatozoa of Culmenella also have distinctive characters (three glycogen helices and high-profile surface ridge in the apical portion of the midpiece) that should be potentially useful in resolving the taxonomic position of this genus.
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Zhu, Zhendong, Rongnan Li, Gongzhen Ma, Wenjing Bai, Xiaoteng Fan, Yinghua Lv, Jun Luo y Wenxian Zeng. "5’-AMP-Activated Protein Kinase Regulates Goat Sperm Functions via Energy Metabolism In Vitro". Cellular Physiology and Biochemistry 47, n.º 6 (2018): 2420–31. http://dx.doi.org/10.1159/000491616.
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Background/Aims: ATP is essential for mammalian sperm to survive and maintain fertilizing capacity. AMP-activated protein kinase (AMPK) is a sensor of cellular energy status. The aims of the present study were to explore the localization of AMPK in goat sperm and to investigate whether and how AMPK regulates sperm functions in vitro. Methods: Sperm were treated with AMPK modulators (AICAR, metformin and Compound C) during incubation. Sperm motility was assessed with a computer-assisted spermatozoa analysis system (CASA). Membrane integrity, acrosome reaction and mitochondrial membrane potentials were detected by SYBR-14/PI, FITC-PNA and JC-1 staining, respectively. And the lactate content, ATP content, AMPK activity, activity of pyruvate kinase (PK) and lactate dehydrogenase (LDH) were also measured with the commercial assay kits. Immunofluorescence staining was used to analyze the distribution of PK, LDH, AMPK and phospho-Thr172-AMPK in sperm. The role of AMPK was further studied during induction of capacitation and acrosome reaction. Results: We found that AMPKα was localized in the entire acrosomal region, the midpiece and the flagellum, while the phospho-Thr172-AMPK was distributed in the head, the midpiece and flagellum. Activation of AMPK by AICAR and metformin significantly improved sperm motility, membrane integrity and acrosome reaction, largely maintained sperm mitochondrial membrane potentials, lactate content and ATP content, and enhanced the activity of AMPK, PK and LDH, whereas inhibition by Compound C triggered the converse effects. Moreover, PK was localized in the acrosomal area and the midpiece, while LDH was distributed in the tail. Induction of capacitation and acrosome reaction led to AMPK phosphorylation. AMPK phosphorylation regulated the activity of energetic enzymes. Conclusion: This study for the first time provides evidence that AMPK governs goat sperm functions through energy metabolism in vitro. This finding will help to improve assisted reproductive techniques in goats and the other species.
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Cabeza, Urbano, César Ordóñez, Aydee Meza y Hernán Cucho. "Morphological and morphometric characterization of the guinea pig sperm (Cavia porcellus)". SPERMOVA 10, n.º 2 (31 de diciembre de 2020): 94–101. http://dx.doi.org/10.18548/aspe/0008.14.
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The aim of this study was to determine the morphological and morphometric characteristics of guinea pig sperm (Cavia porcellus), using an image analysis system. Semen from collected from five type 1 guinea pigs, four months old (1.19 ± 0.15 kg) by electroejaculation method, between 3 and 5 times for each animal, making a total of 22 adequate collections. The volume, pH, sperm concentration, total motility and percentage of live sperm were determined. The samples for the analysis of sperm morphology and morphometry were stained with Spermac® and analyzed using the Motic Image Plus® software. The morphology was analyzed according to the dynamics of its acrosomal reaction, distinguishing 4 classes. The length, width, area, perimeter, ellipticity, elongation, regularity and rugosity of the head of the guinea pig sperm were determined, as well as the midpiece length and the tail of the spermatozoa. Guinea pig sperm morphology was analyzed with a complete random design, and the morphometric parameters by random blocks, using Duncan's test to compare means in both cases. In relation to morphology, significant differences (P <0.05) were found in the percentage distribution of classes, the most recurrent being class 2 (41.67%), higher than the other 3 groups. An animal effect (P <0.05) was found in the morphometric variables of head and midpiece of guinea pig spermatozoa. The morphometric measurements of guinea pig spermatozoa were: length (7.45 ± 0.29 µm), width (6.55 ± 0.25 µm), area (43.02 ± 3.03 µm2), perimeter (26.56 ± 1.07 µm), midpiece length (12.02 ± 0.70 µm) and spermatozoa tail length (92.96 ± 3.96 µm).
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Cabeza, Urbano, César Ordóñez, Aydee Meza y Hernán Cucho. "Morphological and morphometric characterization of the guinea pig sperm (Cavia porcellus)". SPERMOVA 10, n.º 2 (31 de diciembre de 2020): 94–101. http://dx.doi.org/10.18548/aspe/0008.14.
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The aim of this study was to determine the morphological and morphometric characteristics of guinea pig sperm (Cavia porcellus), using an image analysis system. Semen from collected from five type 1 guinea pigs, four months old (1.19 ± 0.15 kg) by electroejaculation method, between 3 and 5 times for each animal, making a total of 22 adequate collections. The volume, pH, sperm concentration, total motility and percentage of live sperm were determined. The samples for the analysis of sperm morphology and morphometry were stained with Spermac® and analyzed using the Motic Image Plus® software. The morphology was analyzed according to the dynamics of its acrosomal reaction, distinguishing 4 classes. The length, width, area, perimeter, ellipticity, elongation, regularity and rugosity of the head of the guinea pig sperm were determined, as well as the midpiece length and the tail of the spermatozoa. Guinea pig sperm morphology was analyzed with a complete random design, and the morphometric parameters by random blocks, using Duncan's test to compare means in both cases. In relation to morphology, significant differences (P <0.05) were found in the percentage distribution of classes, the most recurrent being class 2 (41.67%), higher than the other 3 groups. An animal effect (P <0.05) was found in the morphometric variables of head and midpiece of guinea pig spermatozoa. The morphometric measurements of guinea pig spermatozoa were: length (7.45 ± 0.29 µm), width (6.55 ± 0.25 µm), area (43.02 ± 3.03 µm2), perimeter (26.56 ± 1.07 µm), midpiece length (12.02 ± 0.70 µm) and spermatozoa tail length (92.96 ± 3.96 µm).
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Birkhead, Timothy R., Simone Immler, E. Jayne Pellatt y Robert Freckleton. "Unusual Sperm Morphology in the Eurasian Bullfinch (Pyrrhula Pyrrhula)". Auk 123, n.º 2 (1 de abril de 2006): 383–92. http://dx.doi.org/10.1093/auk/123.2.383.
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Abstract The sperm of the Eurasian Bullfinch (Pyrrhula pyrrhula) differs markedly in gross morphology from that of all other passerines examined to date. In other passerines, the sperm head is pointed and helical, and the midpiece comprises a mitochondrial helix extending along the flagellum; whereas in the Eurasian Bullfinch, the sperm acrosome is rounded, not helical, and the midpiece is extremely short. In a pairwise study, using principal component analysis (PCA), we combined quantitative and qualitative sperm morphology traits and conducted a phylogenetic correlation to compare the sperm morphology of Eurasian Bullfinch and Beavan's Bullfinch (P. erythaca) with nine other pairs of congeneric passerines. The analysis revealed that Eurasian Bullfinch was a dramatic outlier in sperm morphology and that Eurasian and Beavan's bullfinches are more different than any other pair of species. Excluding Eurasian Bullfinch from the analysis showed that most variation in sperm morphology in the other species was attributable to phylogeny. The Eurasian Bullfinch also has extremely small testes for its body size, which indicates that sperm competition is infrequent in this species; we discuss the possibility that relaxed selection, via lack of sperm competition, may have contributed to the species' unusual sperm morphology. Morfología Espermática Inusual en Pyrrhula pyrrhula
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Alavi, Sayyed Mohammad Hadi, Ian A. E. Butts, Azadeh Hatef, Maren Mommens, Edward A. Trippel, Matthew K. Litvak y Igor Babiak. "Sperm morphology, ATP content, and analysis of motility in Atlantic halibut (Hippoglossus hippoglossus)". Canadian Journal of Zoology 89, n.º 3 (marzo de 2011): 219–28. http://dx.doi.org/10.1139/z10-113.
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Spermatozoon of Atlantic halibut ( Hippoglossus hippoglossus (L., 1758)) is uniflagellated, lacks an acrosome, and is differentiated into a head, midpiece, and flagellum. There are two to five mitochondria in the midpiece, as well as proximal and distal centrioles. The flagellum consisted of 9 + 2 microtubules surrounded by plasma membrane, which is extended at the proximal part of the flagellum owing to the presence of vacuoles. After sperm activation in seawater, sperm motility and velocity decreased from 98.4% ± 3.4% and 170.3 ± 8.9 µm·s–1 at 15 s after sperm activation to 4.8% ± 4.7% and 9.2 ± 8.9 µm·s–1 at 120 s after sperm activation, respectively. ATP content (nmol·L–1 ATP per 108 spermatozoa) significantly decreased at 60 s after sperm activation (5.9 ± 1.5) compared with at 0 and 30 s after sperm activation (14.9 ± 1.5 and 14.5 ± 1.5, respectively). Beating waves propagated along the full length of the flagellum after sperm activation, whereas waves were restricted to the proximal section during the latter motility period. Wave amplitude significantly decreased at 45 s after sperm activation, but wavelength did not differ. The present study showed associations among sperm morphology, ATP content, flagellar wave parameters, and sperm velocity, which could be used in comparative spermatology.
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Jamieson, B. G. M. y L. Koehler. "The ultrastructure of the spermatozoon of the northern water snake, Nerodia sipedon (Colubridae, Serpentes), with phylogenetic considerations". Canadian Journal of Zoology 72, n.º 9 (1 de septiembre de 1994): 1648–52. http://dx.doi.org/10.1139/z94-220.
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The ultrastructure of the spermatozoon of Nerodia sipedon conforms closely to that of other described snake sperm: it is filiform; the acrosome vesicle is in the form of a hollow, concentrically zoned cone that basally overlies a subacrosomal cone which invests the tapered anterior end of the nucleus; the putative perforatorium is a slender rod extending anteriorly from the subacrosomal cone; the midpiece contains dense bodies and mitochondria; the axonemal fibrous sheath extends anteriorly into the midpiece (squamate autapomorphy); 9 peripheral dense fibres surround the distal centriole and the axoneme in the midpiece, of which fibres adjacent to 3 and 8 are enlarged; and the endpiece lacks peripheral fibres and the fibrous sheath. The midpiece is very long (a synapomorphy of the Serpentes) and is surrounded by a multilaminar membrane (an autapomorphy). In the squamates, only snakes, including N. sipedon, retain microtubules external to the plasma membrane of the mature spermatozoon. Helically arranged zigzag mitochondria are shared (probably homoplasically) with iguanid sperm. A poorly developed "stopperlike" putative perforatorial base plate in N. sipedon, unknown in other snakes, is questionably homologous with that of gekkonids. An electron-lucent space caps the nuclear point, as in the snakes Boiga irregularis and Stegonotus cucullatus and in some other squamate orders.
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Costello, Sarah, Francesco Michelangeli, Katherine Nash, Linda Lefievre, Jennifer Morris, Gisela Machado-Oliveira, Christopher Barratt, Jackson Kirkman-Brown y Stephen Publicover. "Ca2+-stores in sperm: their identities and functions". REPRODUCTION 138, n.º 3 (septiembre de 2009): 425–37. http://dx.doi.org/10.1530/rep-09-0134.
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Intracellular Ca2+stores play a central role in the regulation of cellular [Ca2+]iand the generation of complex [Ca2+] signals such as oscillations and waves. Ca2+signalling is of particular significance in sperm cells, where it is a central regulator in many key activities (including capacitation, hyperactivation, chemotaxis and acrosome reaction) yet mature sperm lack endoplasmic reticulum and several other organelles that serve as Ca2+stores in somatic cells. Here, we review i) the evidence for the expression in sperm of the molecular components (pumps and channels) which are functionally significant in the activity of Ca2+stores of somatic cells and ii) the evidence for the existence of functional Ca2+stores in sperm. This evidence supports the existence of at least two storage organelles in mammalian sperm, one in the acrosomal region and another in the region of the sperm neck and midpiece. We then go on to discuss the probable identity of these organelles and their discrete functions: regulation by the acrosome of its own secretion and regulation by membranous organelles at the sperm neck (and possibly by the mitochondria) of flagellar activity and hyperactivation. Finally, we consider the ability of the sperm discretely to control mobilisation of these stores and the functional interaction of stored Ca2+at the sperm neck/midpiece with CatSper channels in the principal piece in regulation of the activities of mammalian sperm.
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Bauer, M. y W. G. Breed. "Variation of sperm head shape and tail length in a species of Australian hydromyine rodent: the spinifex hopping mouse, Notomys alexis". Reproduction, Fertility and Development 18, n.º 7 (2006): 797. http://dx.doi.org/10.1071/rd06045.
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In Australia, there are around 60 species of murid rodents that occur in the subfamily Hydromyinae, most of which produce highly complex, monomorphic, spermatozoa in which the head has an apical hook together with two ventral processes containing filamentous actin and a long tail of species-specific length. One of the few exceptions to this is the spinifex hopping mouse, Notomys alexis, whose spermatozoa have previously been shown to have pleiomorphic heads. In this study, the structural organisation of the sperm head has been investigated in more detail and the variability in length of the midpiece and total length of the sperm tail has been determined for this species. The findings confirm that pleiomorphic sperm heads are invariably present in these animals and that this variability is associated with that of the nucleus, although nuclear vacuoles were not evident. The total length of the sperm tail, as well as that of the midpiece, was also highly variable both within, as well as between, individual animals. The reason(s) for this high degree of variability in sperm morphology is not known but it may relate to a relaxation of the genetic control of sperm form owing to depressed levels of inter-male sperm competition.
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Ugajin, Tomohisa, Yukihiro Terada, Hisataka Hasegawa, Hiroshi Nabeshima, Kichiya Suzuki y Nobuo Yaegashi. "The shape of the sperm midpiece in intracytoplasmic morphologically selected sperm injection relates sperm centrosomal function". Journal of Assisted Reproduction and Genetics 27, n.º 2-3 (12 de diciembre de 2009): 75–81. http://dx.doi.org/10.1007/s10815-009-9371-1.
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MATOS, E., M. N. S. SANTOS y C. AZEVEDO. "Biflagellate spermatozoon structure of the hermaphrodite fish Satanoperca jurupari (Heckel, 1840) (Teleostei, Cichlidae) from the Amazon River". Brazilian Journal of Biology 62, n.º 4b (noviembre de 2002): 847–52. http://dx.doi.org/10.1590/s1519-69842002000500014.
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The ultrastructural features of the sperm were studied in the hermaphroditic teleost Satanoperca jurupari HECKEL, 1840 from Amazon River. Spermatocytes, spermatids and sperm develop in the testicular cysts among the different oocyte stages. Different stages of early spermatocyte development, mainly the ones with synaptonemal complexes were often observed. The mature spermatozoa belong to the introsperm type, with a short head (~ 3 mm long and 1.3 mum wide) without acrosome, short midpiece (~ 1.2 mum long and 1.8 mum wide) containing several mitochondria surrounding two centrioles and forming a mitochondrial collar. They have two flagella (each ~15 mum long) each of which has a common 9 + 2 microtubular pattern. Each flagellum has two opposite lateral cytoplasmic extensions that begin about 3 mum the midpiece still close to the end piece of flagellum.
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Andraszek, Katarzyna, Dorota Banaszewska, Olga Szeleszczuk, Marta Kuchta-Gładysz y Anna Grzesiakowska. "Morphometric Characteristics of the Spermatozoa of Blue Fox (Alopex lagopus) and Silver Fox (Vulpes vulpes)". Animals 10, n.º 10 (20 de octubre de 2020): 1927. http://dx.doi.org/10.3390/ani10101927.
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The results presented in this study are the first such extensive characterization of the sperm morphometry of the blue fox (Alopex lagopus) and silver fox (Vulpes vulpes), as representatives of the family Canidae. Canine spermatozoa, especially the sperm of farmed foxes, are not often described in studies on reproduction. The aim of the study was a detailed comparison of the morphometric dimensions and shape of the sperm of two fox species: silver fox and blue fox. Semen collected from 10 silver foxes and 10 blue foxes was used for the study. The specimens were stained with silver nitrate. Measurements were performed of the length, width, perimeter, and area of the head; the area of the acrosome and its coverage; the length of the midpiece and its coverage; the length of the tail; and the length of the end piece of the tail. In addition, four head shape indices were calculated: ellipticity, elongation, roughness and regularity. The following values for the morphometric parameters and shape indices were obtained for blue fox and silver fox, respectively: head length—6.72 µm and 6.33 µm; head width—4.54.µm and 4.21 µm; head perimeter—18.11 µm and 17.37 µm; head area—21.94 µm2 and 21.11 µm2; acrosome area—11.50 µm2 and 10.92 µm2; midpiece length—12.85 µm and 12.79 µm; tail end piece length—3.44 µm and 3.28 µm; tail length—65.23 µm and 65.09 µm; acrosome coverage—52.43% and 52.83%; midpiece coverage—19.71% and 19.65%; sperm length—71.95 µm and 71.42 µm; ellipticity—1.49 and 1.52; elongation—0.19 and 0.20; roughness—0.84 and 1.88; regularity—1.09 and 0.99. The significance of differences between species was verified by Tukey’s test at p ≤ 0.05. Statistically significant differences between species were found for the following parameters: head length, width, perimeter and area; acrosome area; tail, end piece, and total sperm length; roughness and regularity. The differences in the size and shape of sperm can be used to establish reference patterns for fox sperm enabling more accurate species identification.
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DiLauro, Martin N., Wayne S. Kaboord y Rosemary A. Walsh. "Sperm-cell ultrastructure of North American sturgeons. II. The shortnose sturgeon (Acipenser brevirostrum, Lesueur, 1818)". Canadian Journal of Zoology 77, n.º 2 (1 de agosto de 1999): 321–30. http://dx.doi.org/10.1139/z98-219.
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The fine structure of the sperm cell of the shortnose sturgeon (Acipenser brevirostrum) was examined using transmission electron microscopy and selected metrics. The cell possesses a distinct acrosome, a defined head region, a midpiece, and a single flagellum. The mean length of the sperm cell body (acrosome + nucleus + midpiece) is approximately 9.71 µm, and the length of the flagellum is about 37 µm, resulting in a total cell length of about 46 µm. The sperm cell of the shortnose sturgeon is much longer and slightly wider than that of the Atlantic sturgeon. The nuclei of shortnose, white, and stellate sturgeon sperm cells are elongate trapezoids with the anterior (acrosome) end narrowest, the opposite of that of the Atlantic sturgeon. Although slightly smaller in total length and width than the sperm cells of the stellate and white sturgeons, that of the shortnose sturgeon is most similar to them in overall ultrastructure, as all three cells have three endonuclear canals. A structural connection of unknown function between the nuclear fossa and the proximal centriole, which is similar to the fibrous body in other species, is present in the shortnose sturgeon sperm cell. Our results suggest a more recent evolutionary link between the shortnose, white, and stellate sturgeons than between any of these and the Atlantic sturgeon. This is the first description of sperm cell ultrastructure in the shortnose sturgeon, an endangered species.
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Lefièvre, Linda, Katherine Nash, Steven Mansell, Sarah Costello, Emma Punt, Joao Correia, Jennifer Morris et al. "2-APB-potentiated channels amplify CatSper-induced Ca2+ signals in human sperm". Biochemical Journal 448, n.º 2 (7 de noviembre de 2012): 189–200. http://dx.doi.org/10.1042/bj20120339.
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Ca2+i signalling is pivotal to sperm function. Progesterone, the best-characterized agonist of human sperm Ca2+i signalling, stimulates a biphasic [Ca2+]i rise, comprising a transient and subsequent sustained phase. In accordance with recent reports that progesterone directly activates CatSper, the [Ca2+]i transient was detectable in the anterior flagellum (where CatSper is expressed) 1–2 s before responses in the head and neck. Pre-treatment with 5 μM 2-APB (2-aminoethoxydiphenyl borate), which enhances activity of store-operated channel proteins (Orai) by facilitating interaction with their activator [STIM (stromal interaction molecule)] ‘amplified’ progesterone-induced [Ca2+]i transients at the sperm neck/midpiece without modifying kinetics. The flagellar [Ca2+]i response was unchanged. 2-APB (5 μM) also enhanced the sustained response in the midpiece, possibly reflecting mitochondrial Ca2+ accumulation downstream of the potentiated [Ca2+]i transient. Pre-treatment with 50–100 μM 2-APB failed to potentiate the transient and suppressed sustained [Ca2+]i elevation. When applied during the [Ca2+]i plateau, 50–100 μM 2-APB caused a transient fall in [Ca2+]i, which then recovered despite the continued presence of 2-APB. Loperamide (a chemically different store-operated channel agonist) enhanced the progesterone-induced [Ca2+]i signal and potentiated progesterone-induced hyperactivated motility. Neither 2-APB nor loperamide raised pHi (which would activate CatSper) and both compounds inhibited CatSper currents. STIM and Orai were detected and localized primarily to the neck/midpiece and acrosome where Ca2+ stores are present and the effects of 2-APB are focussed, but store-operated currents could not be detected in human sperm. We propose that 2-APB-sensitive channels amplify [Ca2+]i elevation induced by progesterone (and other CatSper agonists), amplifying, propagating and providing spatio-temporal complexity in [Ca2+]i signals of human sperm.
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Westhoff, D. y G. Kamp. "Glyceraldehyde 3-phosphate dehydrogenase is bound to the fibrous sheath of mammalian spermatozoa". Journal of Cell Science 110, n.º 15 (1 de agosto de 1997): 1821–29. http://dx.doi.org/10.1242/jcs.110.15.1821.
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Evidence is provided that the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase is covalently linked to the fibrous sheath. The fibrous sheath is a typical structure of mammalian spermatozoa surrounding the axoneme in the principal piece of the flagellum. More than 90% of boar sperm glyceraldehyde 3-phosphate dehydrogenase activity is sedimented after cell disintegration by centrifugation. Detergents, different salt concentrations or short term incubation with chymotrypsin do not solubilize the enzyme, whereas digestion with trypsin or elastase does. Short term incubation with trypsin (15 minutes) even resulted in an activation of glyceraldehyde 3-phosphate dehydrogenase. Purification on phenyl-Sepharose yielded a homogeneous glyceraldehyde 3-phosphate dehydrogenase as judged from gel electrophoresis SDS-PAGE and native gradient PAGE. The molecular masses are 41.5 and 238 kDa, respectively, suggesting native glyceraldehyde 3-phosphate dehydrogenase to be a hexamer. Rabbit polyclonal antibodies raised to purified glyceraldehyde 3-phosphate dehydrogenase show a high specificity for mammalian spermatozoal glyceraldehyde 3-phosphate dehydrogenase, while other proteins of boar spermatozoa or the muscle glyceraldehyde 3-phosphate dehydrogenase are not labelled. Immunogold staining performed in a post-embedding procedure reveals the localization of glyceraldehyde 3-phosphate dehydrogenase along the fibrous sheath in spermatozoa of boar, bull, rat, stallion and man. Other structures such as the cell membrane, dense fibres, the axoneme or the mitochondria are free of label. During the process of sperm maturation, most of the cytoplasm of the sperm midpiece is removed as droplets during the passage through the epididymis. The labelling of this cytoplasm, in immature boar spermatozoa and in the droplets, indicates that glyceraldehyde 3-phosphate dehydrogenase is completely removed from the midpiece during sperm maturation in the epididymis. The inverse compartmentation of the glycolytic enzyme and mitochondria in the mammalian sperm flagella suggests that ATP-production in the principal piece mainly occurs by glycolysis and in the midpiece by respiration.
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Tsuneda, P. P., L. K. Hatamoto-Zervoudakis, T. F. Motheo, J. T. Zervoudakis y M. Nichi. "39 General motility and mitochondrial cytochemical activity of post-thawed semen of pasture-fed Nelore bulls supplemented with palm and soybean oils". Reproduction, Fertility and Development 31, n.º 1 (2019): 145. http://dx.doi.org/10.1071/rdv31n1ab39.
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This study aimed to evaluate general motility and mitochondrial cytochemical activity of post-thawed semen of pasture-fed Nelore bulls supplemented with palm and soybean oils (protected by calcium salts). Twenty-four young male Nellore bulls were randomly assigned to 2 groups: control (CO; corn supplement and distillery grains without the addition of protected fat) and palm and soybean oils association (OP+OS; control supplement+145g of protected soybean oil+145g of protected palm). The experiment lasted 84 days, and semen was collected for cryopreservation. Post-thawed general sperm motility was assessed by computer-assisted sperm analysis using a computerized analyser (HTR Ivos II; Hamilton Thorne, Beverly, MA, USA). Motility (%), progressive motility (%), velocity average path (μm s−1), linearity (%), and lateral displacement of sperm head (μm) were analysed. Additionally, mitochondrial cytochemical activity was evaluated by co-incubation with 3,3′-diaminobenzidine (DAB; 1mg mL−1 of PBS) at 37°C (water bath) for 1h under reduced lighting conditions. Sperm cells were classified based on the mitochondrial activity of their midpiece in a 4-class scale: class 1 (DAB 1; all mitochondria are active; sperm cells with midpiece completely stained), class 2 (DAB 2; sperm cells with active and inactive segments but with prevalence of active stained segments, indicating average to high mitochondrial activity), class 3 (DAB 3; spermatozoa with less than half of the mitochondrial sheath active), and class 4 (DAB 4; spermatozoa totally inactive, with midpiece completely discolored). Data were analysed using SAS statistical program (SAS 9.3, SAS Institute Inc., Cary, NC, USA), and Tukey’s test was used to identify treatments. Study design was completely randomized, and effects were declared significant at P<0.05. Increased percentage of sperm motility (CO: 30.27±5.44v. OP+OS: 38.90±4.68) and progressive motility (CO: 17.27±3.84v. OP+OS: 22.90±3.88) were noticed in post-thawed samples after supplementation. Nevertheless, the addition of palm and soybean oils to the feed promoted a decrease in the percentage of DAB 3 sperm cells (CO: 4.77±1.03v. OP+OS: 2.06±0.51; P=0.0267). Therefore, supplementation with palm and soybean oils improves sperm kinetics in post-thawed semen of grazing Nellore bulls.
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Abraham-Peskir, J. V. "Response of midpiece vesicles on human sperm to osmotic stress". Human Reproduction 17, n.º 2 (1 de febrero de 2002): 375–82. http://dx.doi.org/10.1093/humrep/17.2.375.
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Gonzalez-Castro, Raul A., Fabio Amoroso-Sanches, JoAnne E. Stokes, James K. Graham y Elaine M. Carnevale. "Localisation of phospholipase Cζ1 (PLCZ1) and postacrosomal WW-binding protein (WBP2 N-terminal like) on equine spermatozoa and flow cytometry quantification of PLCZ1 and association with cleavage in vitro". Reproduction, Fertility and Development 31, n.º 12 (2019): 1778. http://dx.doi.org/10.1071/rd19217.
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Oocyte activation is initiated when a fertilising spermatozoon delivers sperm-borne oocyte-activating factor(s) into the oocyte cytoplasm. Candidates for oocyte activation include two proteins, phospholipase Cζ1 (PLCZ1) and postacrosomal WW-binding protein (PAWP; also known as WBP2 N-terminal like (WBP2NL)). We localised PLCZ1 and WBP2NL/PAWP in stallion spermatozoa and investigated the PLCZ1 content and sperm parameters as well as cleavage after intracytoplasmic sperm injection (ICSI). PLCZ1 was identified as 71-kDa protein in the acrosomal and postacrosomal regions, midpiece and principal piece of the tail. Anti-WBP2NL antibody identified two WBP2NL bands (~28 and ~32kDa) in the postacrosomal region, midpiece and principal piece of the tail. PLCZ1 and WBP2NL expression was positively correlated (P=0.04) in sperm heads. Flow cytometry evaluation of PLCZ1 revealed large variations in fluorescence intensity and the percentage of positively labelled spermatozoa among stallions. PLCZ1 expression was significantly higher in viable than non-viable spermatozoa, and DNA fragmentation was negatively correlated with PLCZ1 expression and the percentage of positively labelled spermatozoa (P<0.05). The use of equine sperm populations considered to have high versus low PLCZ1 content resulted in significantly higher cleavage rates after ICSI of bovine and equine oocytes, supporting the importance of PLCZ1 for oocyte activation.
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Lüpold, Stefan, Sara Calhim, Simone Immler y Tim R. Birkhead. "Sperm morphology and sperm velocity in passerine birds". Proceedings of the Royal Society B: Biological Sciences 276, n.º 1659 (23 de diciembre de 2008): 1175–81. http://dx.doi.org/10.1098/rspb.2008.1645.
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Sperm velocity is one of the main determinants of the outcome of sperm competition. Since sperm vary considerably in their morphology between and within species, it seems likely that sperm morphology is associated with sperm velocity. Theory predicts that sperm velocity may be increased by enlarged midpiece (energetic component) or flagellum length (kinetic component), or by particular ratios between sperm components, such as between flagellum length and head size. However, such associations have rarely been found in empirical studies. In a comparative framework in passerine birds, we tested these theoretical predictions both across a wide range of species and within a single family, the New World blackbirds (Icteridae). In both study groups, sperm velocity was influenced by sperm morphology in the predicted direction. Consistent with theoretical models, these results show that selection on sperm morphology and velocity are likely to be concomitant evolutionary forces.
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Zainuddin, Zainal Zahari, Mohamed Reza Mohamed Tarmizi, Yap Keng Chee, Alvin Erut, Wan Nor Fitri y Annas Salleh. "A preliminary study on semen collection, its evaluation, and testicular and sperm morphometries in the wild proboscis monkey (Nasalis larvatus)". Journal of Veterinary Research 65, n.º 3 (1 de septiembre de 2021): 375–81. http://dx.doi.org/10.2478/jvetres-2021-0048.
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Abstract Introduction The proboscis monkey (Nasalis larvatus) is an endangered species with a declining population. This article describes the first successful attempt at sperm collection and evaluation, and the testicular and sperm morphometries of the wild proboscis monkey in Sabah, Malaysia. Material and Methods Eight semen collection procedures using electro-ejaculation and digital manipulation were conducted in three wild adult male proboscis monkeys. A total of 21 ejaculates were collected. The testicular biometry was measured with the aid of ultrasonography. Sample evaluation included semen volume and pH and sperm concentration, viability, and abnormality. The sperm morphometry was undertaken using phase contrast microscopy. Results The mean (±SD) total testicular volume of these animals was 5.77 cm3 (±1.58). Semen collection by electro-ejaculation resulted in an 84% success rate, while digital manipulation did not result in any ejaculation. Each animal showed different semen characteristics, where the volume was 5–540 μL, pH 8–9, and sperm concentration 0.041–83.00 ×106/mL. The percentage of abnormal sperm was high at 76.8% (±89.60), largely due to midpiece abnormality. Normal sperm had a spherical head and long tail with a head : midpiece : tail length ratio of 1 : 2: 8. Conclusion The social status of these animals may contribute to the generally low quality of the semen. The techniques and data from this study are useful for future conservation and application of assisted reproductive technology in this species.
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Zee, Yeng Peng, William V. Holt, Camryn D. Allen, Vere Nicolson, Michelle Burridge, Allan Lisle, Frank N. Carrick y Steve D. Johnston. "Effects of cryopreservation on mitochondrial function and heterogeneity, lipid raft stability and phosphatidylserine translocation in koala (Phascolarctos cinereus) spermatozoa". Reproduction, Fertility and Development 19, n.º 7 (2007): 850. http://dx.doi.org/10.1071/rd07084.
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Koala sperm mitochondria were examined by cryomicroscopy using the fluorescent probe JC-1, which distinguishes high (red) and low (green) mitochondrial membrane potential (MMP). At normal body temperature, ~70% of live and untreated spermatozoa exhibited high MMP whereas <3% of live untreated spermatozoa exhibited low potential. A third class, in which single midpieces contained mixed mitochondrial populations, was also detected. Heterogeneity was noted in the level of MMP between individual koalas, individual spermatozoa and even between mitochondrial gyres within single midpieces. MMP of the live sperm population was not significantly affected by glycerol but was suppressed by freezing and thawing treatments. After thawing, MMP declined significantly during rewarming, especially as the temperature increased from 5 to 35°C. The distribution of the ganglioside GM1 was examined using fluorescent-labelled cholera toxin B. In fresh, untreated koala spermatozoa GM1 was detected on the head and midpiece, but not on the principal piece. No significant redistribution of GM1 was observed after chilling and cryotreatment. Phosphatidylserine translocation across the plasma membrane was examined using fluorescent-labelled annexin V. Few fresh spermatozoa exhibited phosphatidylserine translocation (~1%); this was not increased by chilling or cryopreservation, thus implying that cryotreatment had little effect on plasma membrane lipid asymmetry.
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DiLauro, Martin N., Wayne S. Kaboord y Rosemary A. Walsh. "Sperm-cell ultrastructure of North American sturgeons. III. The lake sturgeon (Acipenser fulvescens Rafinesque, 1817)". Canadian Journal of Zoology 78, n.º 3 (1 de abril de 2000): 438–47. http://dx.doi.org/10.1139/z99-241.
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Lake sturgeon (Acipenser fulvescens) sperm cell fine structure was examined using transmission electron microscopy. The cell possesses a distinct acrosome, a defined head region, a midpiece, and a single flagellum. Sperm cells of this species share a general radial symmetry, an elongate shape, a distinct acrosome, and the presence of endonuclear canals with those of other sturgeons. The mean length of the lake sturgeon sperm cell body (acrosome + nucleus + midpiece) is approximately 7.13 µm and the length of the flagellum is about 50 µm, resulting in a total cell length of about 57 µm. The lake sturgeon sperm cell is much longer and slightly wider than that of the Atlantic sturgeon. The sperm-cell nuclei of lake, shortnose, white, and stellate sturgeons are elongate trapezoids in shape, with the anterior (acrosome) end narrowest but, in the Atlantic sturgeon, the anterior portion of the trapezoid is wider than the posterior. Although slightly smaller in total length and width, the lake sturgeon sperm cell is most similar to the shortnose sperm cell in ultrastructure, overall size, and shape; it also shares similarity of shape with the stellate and white sturgeon sperm cells. The cell nuclei of these four sturgeons have three endonuclear canals. The acrosome of the lake sturgeon sperm cell has longer posterolateral projections than that of the Atlantic or shortnose sturgeon sperm cell. A structural connection, the fibrous body, is present in the lake sturgeon sperm cell between the nuclear fossa and the proximal centriole, as in the Atlantic and shortnose sturgeon sperm cells. Our results suggest a more recent evolutionary linkage between the lake and shortnose sturgeons than with the Atlantic sturgeon. This work presents the first ultrastructural description of the lake sturgeon sperm cell.
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VAAMONDE, Δ., A. SÁNCHEZ DE MEDINA, Β. CORTÉS, Α. DÍAZ y Ι. RODRÍGUEZ. "Effect of trans-resveratrol or ubiquinol supplementation on the sperm morphology of CD-1 mice subjected to forced swimming". Journal of the Hellenic Veterinary Medical Society 71, n.º 3 (15 de octubre de 2020): 2349. http://dx.doi.org/10.12681/jhvms.25096.
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This study was undertaken to assess the effect of a three-minute forced swimming protocol for 50 days, with and without antioxidant administration on sperm morphology in CD-1 mice. Seventy-five mice were randomly allocated to one of the following five groups: no exercise (control group; CG), swimming without antioxidant administration (EX), swimming with trans-resveratrol administration (EX-Resv), swimming with ubiquinol and excipient administration (Kaneka´s ubiquinol) (EX-Ubiq), and swimming with just only the excipient for Kaneka´s ubiquinol administration (EX-Excp). The EX group showed that 53.03±4.83% of sperm had abnormal morphology, with significant differences with regards to CG (46.47±10.57%) (p<0.05). The number of sperm with abnormal morphology decreased in all groups treated with either antioxidants or with excipient; this was most noticeable in EX-Ubiq (p<0.05). The percentage of midpiece and tail, as well as multiple anomalies were greater in EX than in CG (p<0.05). While both antioxidants, as well as the excipient, decreased midpiece and head anomalies, only trans-resveratrol and ubiquinol had an effect on multiple anomalies. Furthermore, only trans-resveratrol had an effect upon tail anomalies. The imposed exercise caused alterations in CD-1 mice sperm morphology, and antioxidant treatment seems suitable to decrease morphological anomalies. Both trans- resveratrol and ubiquinol were effective in decreasing simple as well as multiple sperm anomalies.
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Setiawan, Rangga, Chathura Priyadarshana, Atsushi Tajima, Alexander J. Travis y Atsushi Asano. "Localisation and function of glucose transporter GLUT1 in chicken (Gallus gallus domesticus) spermatozoa: relationship between ATP production pathways and flagellar motility". Reproduction, Fertility and Development 32, n.º 7 (2020): 697. http://dx.doi.org/10.1071/rd19240.
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Glucose plays an important role in sperm flagellar motility and fertility via glycolysis and oxidative phosphorylation, although the primary mechanisms for ATP generation vary between species. The glucose transporter 1 (GLUT1) is a high-affinity isoform and a major glucose transporter in mammalian spermatozoa. However, in avian spermatozoa, the glucose metabolic pathways are poorly characterised. This study demonstrates that GLUT1 plays a major role in glucose-mediated motility of chicken spermatozoa. Using specific antibodies and ligand, we found that GLUT1 was specifically localised to the midpiece. Sperm motility analysis showed that glucose supported sperm movement during incubation for 0–80min. However, this was abolished by the addition of a GLUT1 inhibitor, concomitant with a substantial decrease in glucose uptake and ATP production, followed by elevated mitochondrial activity in response to glucose addition. More potent inhibition of ATP production and mitochondrial activity was observed in response to treatment with uncouplers of oxidative phosphorylation. Because mitochondrial inhibition only reduced a subset of sperm movements, we investigated the localisation of the glycolytic pathway and showed glyceraldehyde-3-phosphate dehydrogenase and hexokinase I at the midpiece and principal piece of the flagellum. The results of this study provide new insights into the mechanisms involved in ATP production pathways in avian spermatozoa.
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Feiden, Sandra, Uwe Wolfrum, Gerhard Wegener y Günter Kamp. "Expression and compartmentalisation of the glycolytic enzymes GAPDH and pyruvate kinase in boar spermatogenesis". Reproduction, Fertility and Development 20, n.º 6 (2008): 713. http://dx.doi.org/10.1071/rd08004.
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Boar spermatozoa contain isoforms of both glyceraldehyde 3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12) and pyruvate kinase (PK, EC 2.7.1.40). The sperm-specific forms, GAPDH-S and PK-S, are tightly bound to cell structures. By immunofluorescence microscopy GAPDH-S and PK-S were localised in the principal piece of the boar sperm flagellum as well as in the acrosomal region of the sperm head and at the head–midpiece junction. The midpiece of the flagellum, however, contains isoforms of GAPDH and PK that were only recognised by antibodies against somatic GAPDH and PK, respectively, but not by the antibodies against GAPDH-S and PK-S. In sections of boar testis, GAPDH-S and PK-S were first detected in elongating spermatids when both the developing flagellum and the head were labelled with antibodies against GAPDH-S and PK-S. In contrast, antibodies against rabbit muscle GAPDH and PK labelled all developmental stages of germ cells and also neighbouring contractile cells. Thus, the structure-bound sperm-specific enzymes, GAPDH-S and PK-S, appeared only late in spermatogenesis simultaneously with the development of the structures to which they are bound. Anchoring glycolytic enzymes to structures in these mitochondria-free regions may secure ATP-production for both motility and acrosome function.
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Sousa, Mário, Elsa Oliveira, Ângela Alves, Mónica Gouveia, Helena Figueiredo, Luís Ferraz, Alberto Barros y Rosália Sá. "Ultrastructural analysis of five patients with total sperm immotility". Zygote 23, n.º 6 (20 de enero de 2015): 900–907. http://dx.doi.org/10.1017/s0967199414000616.
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SummaryAsthenozoospermia has been related to structural defects of the sperm flagellum. However, few reports have studied in detail the ultrastructure of sperm with total immotility. We present an ultrastructural study of sperm from five patients with total sperm immotility, four due to dysplasia of the fibrous sheath (DFS) and one with situs-inversus. Of the four patients with DFS, three cases presented a hypertrophic and hyperplastic fibrous sheath that invaded the midpiece space, absence of the annulus, and a short midpiece containing a few disorganized and pale mitochondria. Of these cases, two presented absence of the central complex and radial spokes; another additionally presented absence of dynein arms and nexin bridges; and the other patient presented an intact annulus with a dysplastic fibrous sheath restricted to the principal piece with disorganized microtubule doublets. The patient with situs-inversus presented severe respiratory symptoms, with absence of dynein arms and nexin bridges. In conclusion, we present three cases with DFS associated with total sperm immotility, abnormal mitochondria, and absence of the annulus, central pair complex and radial spokes, of which one had in addition absence of dynein arms and nexin bridges. We also describe a patient, with total sperm immotility and a different presentation of DFS, as the annulus was present and the dysplastic fibrous sheath was restricted to the principal piece. These findings thus confirm the heterogeneity of the DFS condition. The changes observed in the patient with situs-inversus also further support previous observations.
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Pinto-Correia, C., D. L. Poccia, T. Chang y J. M. Robl. "Dephosphorylation of sperm midpiece antigens initiates aster formation in rabbit oocytes." Proceedings of the National Academy of Sciences 91, n.º 17 (16 de agosto de 1994): 7894–98. http://dx.doi.org/10.1073/pnas.91.17.7894.
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Bhatt, Gaurav, Shurveer Singh, Vivek Bahugua, Ashish K. Chowdhary, Siddhand Bhardwaj y S. N. Bahuguna. "Semen quality and sperm ultrastructure of Himalayan snowtrout Schizothorax plagiostomus Heckel, 1838". Indian Journal of Fisheries 64, n.º 1 (31 de marzo de 2017): 49. http://dx.doi.org/10.21077/ijf.2017.64.1.61169-08.
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The aim of this study was to characterise physical and biochemical aspects of semen as well as to investigate the fine structure of spermatozoa of the Himalayan snowtrout Schizothorax plagiostomus Heckel, 1838 using scanning and transmission electron microscopy. The species breed twice in a year and semen was collected during both seasons, i.e. from 24 males in February and March, 2015 and from 30 males in September and October, 2015. Size of the fish ranged from 13.5 to 36 cm in February-March and 12.3 to 38 cm in September-October. The mean milt volume (ml), sperm density (×1010 ml-1) and spermatocrit (%) values were 2.25±1.26, 2.22±0.53 and 78.87± 8.25 in February-March and 2.12±1.25, 2.12±0.52 and 75.54±8.23 in September-October respectively. Biochemical parameters of seminal plasma viz., total protein (g dl-1), carbohydrates (mg dl-1) and total lipids were 0.312±0.05, 1.348±0.07 and 26.4±2.23 in February-March and 0.340±0.05, 1.34±0.1 and 26.4±3.19 in September-October respectively. Scanning and transmission electron microscopy studies of sperm revealed that the sperm was composed of an ovoid shaped head without acrosome, ellipsoidal midpiece with mitochondria and tail or flagellum. Flagellum had a typical 9+2 axoneme arrangement. The mean length (μm) of head, midpiece, flagella and total length of sperm were 1.82±0.24, 0.35±0.07, 20.18±0.79 and 22.3±3 respectively. For both the breeding seasons, sperm motility decreased significantly with time post-activation.