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1
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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Whiteley, A. R., K. N. Persaud, N. Derome, R. Montgomerie y L. Bernatchez. "Reduced sperm performance in backcross hybrids between species pairs of whitefish (Coregonus clupeaformis)". Canadian Journal of Zoology 87, n.º 7 (julio de 2009): 566–72. http://dx.doi.org/10.1139/z09-042.
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Previous work has demonstrated that genomic incompatibilities work together with ecologically divergent selection to promote and maintain reproductive isolation between incipient species (dwarf and normal) of lake whitefish ( Coregonus clupeaformis (Mitchill, 1818)). Whitefish spawn in groups with external fertilization, which creates conditions for strong sperm competition. In this study, we asked whether reduced sperm performance in hybrids from whitefish species-pair matings might contribute to postzygotic isolating mechanisms between these taxa. We examined two sperm traits, sperm swimming speed and flagellum length, in pure dwarf and normal whitefish and in their F1 and backcross hybrids. We observed significantly reduced sperm swimming speed in backcross but not in F1 hybrids. Sperm flagellum length was not significantly correlated with sperm swimming speed. These results demonstrate that F1 hybrids formed in nature should be capable of the same fertilization success as the parental species during sperm competition, everything else being equal. However, reduced sperm performance in the backcross generation is consistent with other evidence suggesting that genomic incompatibilities create a range of negative fitness effects in post-F1 whitefish hybrids and provides evidence for an additional postzygotic isolation mechanism involved in the incipient speciation of sympatric dwarf and normal whitefish.
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Bourne, H., N. Richings, DY Liu, GN Clarke, O. Harari y HW Baker. "Sperm preparation for intracytoplasmic injection: methods and relationship to fertilization results". Reproduction, Fertility and Development 7, n.º 2 (1995): 177. http://dx.doi.org/10.1071/rd9950177.
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Sperm preparation for intracytoplasmic sperm injection (ICSI) is described and the effect of high speed centrifugation during preparation on fertilization rate is evaluated. No significant differences were found in the 2-pronuclear or abnormal fertilization rates between sibling oocytes injected with sperm prepared by swim-up or mini-Percoll combined with high speed centrifugation. The high fertilization rate obtained with both methods indicates that high speed centrifugation is not necessary to prepare sperm for ICSI. Fertilization rates were also compared for sperm obtained from ejaculates, fresh and frozen epididymal aspirates, and testicular biopsies. High fertilization rates were obtained from all groups but they were significantly higher in those oocytes injected with epididymal sperm (78% per oocyte surviving injection). The high fertilization rate with epididymal sperm may reflect sperm quality or may result from the method of sperm preparation for injection. Fertilization after the injection of sperm from which the tail was dislodged during immobilization was compared with that obtained using intact sperm. A significantly lower rate of 2-pronuclear fertilization was found in those oocytes injected with sperm heads only (55%) compared with intact sperm (68%), although cleavage rates between the two groups were similar. The use of hypo-osmotic medium to select potentially live sperm from an immotile sample is also described and fertilization was obtained after the injection of sperm with a structural defect which were selected using this technique. These results indicate that high fertilization rates can be obtained with ejaculated, epididymal and testicular sperm without special treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Boumaza, Karima y Abdelhamid Loukil. "Computer-Assisted Analysis of Human Semen Concentration and Motility". International Journal of E-Health and Medical Communications 11, n.º 4 (octubre de 2020): 17–33. http://dx.doi.org/10.4018/ijehmc.2020100102.
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Computer-assisted semen analysis systems insist on evaluating sperm characteristics. These systems afford capacity to study and evaluate sperm statistical and morphological characteristics such as concentration, morphology, and motility, which have an important role in diagnosis and treatment of male infertility. In this paper, the proposed algorithm allows the assessment of concentration and motility rate of sperms in microscopic videos. First, enhancement process is required because of microscopic images limitations such as low contrast and noises. Then, for true sperm recognition among noise and debris, a hybrid approach is proposed using a combination between segmentation techniques. After, the use of geometric features of the bounding ellipse of the sperm head led to define sperm concentration. Finally, inter-frame difference is applied for motile sperm detection. The proposed method was tested on microscopic videos of human semen; the performance of this method is analyzed in terms of speed, accuracy, and complexity. Obtained results during the experiments are very promising compared with those obtained by the traditional assessment, which is the most widely used and approved in the laboratories.
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Rosengrave, P., R. Montgomerie, V. J. Metcalf, K. McBride y N. J. Gemmell. "Sperm traits in Chinook salmon depend upon activation medium: implications for studies of sperm competition in fishes". Canadian Journal of Zoology 87, n.º 10 (octubre de 2009): 920–27. http://dx.doi.org/10.1139/z09-081.
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Sperm traits of externally fertilizing fish species are typically measured in fresh (or salt) water, even though the spawning environment of their ova contains ovarian fluid. In this study, we measured sperm traits of Chinook salmon ( Oncorhynchus tshawytscha (Walbaum in Artedi, 1792)) in both fresh water and dilute ovarian fluid at 10 and 20 s postactivation, using a computer-assisted sperm analysis system. Spermatozoa swam faster, and had both higher percent motility and a straighter path trajectory for a longer period of forward motility when activated in ovarian fluid compared with activation in fresh water. Comparing sperm activity of 10 males in water versus ovarian fluid, we found a weak but significant correlation for sperm swimming speed at 10 s postactivation (r = 0.34, p = 0.01), but not for any other sperm traits measured. Most important, across males, mean sperm swimming speed in water accounted for <10% of the observed variation in mean sperm swimming speed in ovarian fluid. Thus, we argue that sperm traits measured in fresh water are not particularly relevant to those same traits during normal spawning in this species. We suggest that sperm performance measured in fresh water should be used with caution when comparing the potential for individual males to fertilize ova, especially in studies of sperm competition in externally fertilizing species.
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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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Vaz Serrano, Jonathan, Ivar Folstad, Geir Rudolfsen y Lars Figenschou. "Do the fastest sperm within an ejaculate swim faster in subordinate than in dominant males of Arctic char?" Canadian Journal of Zoology 84, n.º 7 (1 de julio de 2006): 1019–24. http://dx.doi.org/10.1139/z06-097.
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Theoretical models predict that subordinate males should have higher sperm velocity to compensate for their disadvantaged mating role and because they experience sperm competition more frequently than dominant males. Differences in mean velocity between sperm of dominants and subordinates in the predicted direction are also documented for a few species, including the Arctic char, Salvelinus alpinus (L., 1758). Yet, this difference in mean velocity does not imply that the fastest sperm within an ejaculate, which are those most likely to fertilize eggs, swim faster in subordinates than in dominants. We studied the 5% and 10% fastest sperm cells in ejaculates of dominant and subordinate Arctic char. Before individuals attained their status, there were no differences in velocity between the fastest sperm of males that later became dominant or subordinate. Yet, after establishment of social position, subordinates showed significantly higher sperm swimming speed of the fastest cells in the first 30 s post activation (i.e., at 15, 20, and 30 s post activation). Males that became subordinates showed no change in sperm speed of the fast cells compared with those at pre-trial levels, whereas males that became dominant reduced the speed of their sperm (15 s post activation) compared with those at pre-trial levels. Our results suggest that males which attain social dominance are unable to maintain high sperm velocity, even among the small fraction of the fastest cells.
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Nascimento, Jaclyn M., Linda Z. Shi, Stuart Meyers, Pascal Gagneux, Naida M. Loskutoff, Elliot L. Botvinick y Michael W. Berns. "The use of optical tweezers to study sperm competition and motility in primates". Journal of The Royal Society Interface 5, n.º 20 (24 de julio de 2007): 297–302. http://dx.doi.org/10.1098/rsif.2007.1118.
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Optical trapping is a non-invasive biophysical tool which has been widely applied to study physiological and biomechanical properties of cells. Using laser ‘tweezers’ in combination with custom-designed computer tracking algorithms, the swimming speeds and the relative swimming forces of individual sperm can be measured in real time. This combination of physical and engineering tools has been used to examine the evolutionary effect of sperm competition in primates. The results demonstrate a correlation between mating type and sperm motility: sperm from polygamous (multi-partner) primate species swim faster and with greater force than sperm from polygynous (single partner) primate species. In addition, sperm swimming force linearly increases with swimming speed for each species, yet the regression relating the two parameters is species specific. These results demonstrate the feasibility of using these tools to study rapidly moving (μm s −1 ) biological cells.
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Gee, C. C. y R. K. Zimmer-Faust. "The effects of walls, paternity and ageing on sperm motility." Journal of Experimental Biology 200, n.º 24 (1 de diciembre de 1997): 3185–92. http://dx.doi.org/10.1242/jeb.200.24.3185.
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The measurement of sperm motility is critical when studying fertilization kinetics and chemotaxis. Analysis of motility has traditionally been carried out on cells in small fluid volumes on microscope slides. Several theoretical treatments suggest that drag forces significantly affect flagellar motion within 10 sperm body lengths of the slide surface. Understanding how sperm move in the absence of surface drag is crucial when considering natural locomotory patterns. To examine the effects of solid surfaces, motile sperm from sea urchins (Arbacia punctulata) were placed in a Plexiglas chamber (69 mmx45 mmx15.5 mm; length x width x height). A system was constructed to minimize convective flow by limiting temperature differences within the chamber to less than 0.1 degrees C. The movement of sperm was video-recorded at two levels: (3/4)100 micron (3 body lengths) and 5 mm (150 body lengths) below the chamber lid. When swimming speeds were measured using a computerized video motion-analysis system, a highly significant difference (P<0. 0001) between cells at the two depths was found. Cells nearest the lid swam at 174.6+/-5.9 micron s-1 (mean +/- s.e.m.), whereas those farther away slowed to only 111.1+/-9.9 micron s-1 (mean +/- s.e.m.). Swimming speed was also found to be significantly (P<0.01) affected by paternity, but not by sperm age. We conclude that viscous wall effects must be carefully considered in studies of sperm motility and chemotaxis. The analysis of sperm on a microscope slide may substantially exaggerate swimming speed.
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Gómez Montoto, Laura, María Varea Sánchez, Maximiliano Tourmente, Juan Martín-Coello, Juan José Luque-Larena, Montserrat Gomendio y Eduardo R. S. Roldan. "Sperm competition differentially affects swimming velocity and size of spermatozoa from closely related muroid rodents: head first". REPRODUCTION 142, n.º 6 (diciembre de 2011): 819–30. http://dx.doi.org/10.1530/rep-11-0232.
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Sperm competition favours an increase in sperm swimming velocity that maximises the chances that sperm will reach the ova before rival sperm and fertilise. Comparative studies have shown that the increase in sperm swimming speed is associated with an increase in total sperm size. However, it is not known which are the first evolutionary steps that lead to increases in sperm swimming velocity. Using a group of closely related muroid rodents that differ in levels of sperm competition, we here test the hypothesis that subtle changes in sperm design may represent early evolutionary changes that could make sperm swim faster. Our findings show that as sperm competition increases so does sperm swimming speed. Sperm swimming velocity is associated with the size of all sperm components. However, levels of sperm competition are only related to an increase in sperm head area. Such increase is a consequence of an increase in the length of the sperm head, and also of the presence of an apical hook in some of the species studied. These findings suggest that the presence of a hook may modify the sperm head in such a way that would help sperm swim faster and may also be advantageous if sperm with larger heads are better able to attach to the epithelial cells lining the lower isthmus of the oviduct where sperm remain quiescent before the final race to reach the site of fertilisation.
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Fitzpatrick, John L., Paul M. Craig, Carol Bucking, Sigal Balshine, Chris M. Wood y Grant B. McClelland. "Sperm performance under hypoxic conditions in the intertidal fish Porichthys notatus". Canadian Journal of Zoology 87, n.º 5 (mayo de 2009): 464–69. http://dx.doi.org/10.1139/z09-031.
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Hypoxia (low oxygen) exposure generally leads to decreased reproductive capacity, exhibited by reductions in testicular mass, reproductive hormones, and sperm swimming speed. However, in many fish species, reproduction occurs either periodically or exclusively under hypoxic conditions. In this study we assessed how hypoxia influences sperm performance in the plainfin midshipman ( Porichthys notatus Girard, 1854), a species that lives in intertidal nests that become hypoxic during low tides. We exposed sperm from the same male to normoxic or hypoxic conditions and compared sperm characteristics and oxygen consumption between treatments. Sperm exposed to hypoxic water swam faster and consumed more oxygen than sperm swimming in normoxic conditions. Sperm swimming speed was positively related with oxygen consumption. For each male, the percentage of motile spermatozoa did not differ between treatments, suggesting that the same number of sperm were active but their performance was dependent on the dissolved oxygen content in the water. We discuss the implications of our results in the context of sperm competition and fertilization success under hypoxic conditions.
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Burness, Gary, Stephen J. Casselman, Albrecht I. Schulte-Hostedde, Christopher D. Moyes y Robert Montgomerie. "Sperm swimming speed and energetics vary with sperm competition risk in bluegill ( Lepomis macrochirus )". Behavioral Ecology and Sociobiology 56, n.º 1 (1 de mayo de 2004): 65–70. http://dx.doi.org/10.1007/s00265-003-0752-7.
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Simmons, Leigh W. y John L. Fitzpatrick. "Sperm wars and the evolution of male fertility". REPRODUCTION 144, n.º 5 (noviembre de 2012): 519–34. http://dx.doi.org/10.1530/rep-12-0285.
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Females frequently mate with several males, whose sperm then compete to fertilize available ova. Sperm competition represents a potent selective force that is expected to shape male expenditure on the ejaculate. Here, we review empirical data that illustrate the evolutionary consequences of sperm competition. Sperm competition favors the evolution of increased testes size and sperm production. In some species, males appear capable of adjusting the number of sperm ejaculated, depending on the perceived levels of sperm competition. Selection is also expected to act on sperm form and function, although the evidence for this remains equivocal. Comparative studies suggest that sperm length and swimming speed may increase in response to selection from sperm competition. However, the mechanisms driving this pattern remain unclear. Evidence that sperm length influences sperm swimming speed is mixed and fertilization trials performed across a broad range of species demonstrate inconsistent relationships between sperm form and function. This ambiguity may in part reflect the important role that seminal fluid proteins (sfps) play in affecting sperm function. There is good evidence that sfps are subject to selection from sperm competition, and recent work is pointing to an ability of males to adjust their seminal fluid chemistry in response to sperm competition from rival males. We argue that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity. Research at the genomic level will identify the genes that ultimately control male fertility.
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Engin, Serhat, Şahin Saka y Kürşat Fırat. "Çipura (Sparus aurata, Linneaus, 1758) Spermasının Kısa Süreli Saklanması ve Spermatolojik Özellikleri ile Ebeveyn İlişkilerinin Araştırılması". Turkish Journal of Agriculture - Food Science and Technology 6, n.º 3 (19 de marzo de 2018): 372. http://dx.doi.org/10.24925/turjaf.v6i3.372-379.1756.
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Sperm samples taken from gilthead sea bream obtained from a production farm located in the province of Balıklıova in İzmir were examined under one phase contrast type microscope every six hours after they were kept in ice at 0°C. Data related to sperm maintenance durations, speed, concentration and sperm volume were obtained in the study and these results were related to the parent. The fish weighed 405-625 g and the sperm volume 25-37 cm was 3.1-8.3 ml.kg-1. The most intense concentration was found in the second experiment with 5.35x109 spz.ml-1 and the lowest sperm concentration in the second test with 0.16×109 spz.ml-1. During the study, the highest head speed index was determined for all subjects and time as 35.5 head height.sn-1 (210.16 μm.sn-1) and the lowest head speed was 2.6 head height.sn-1 (15.39 μm.sn-1). The study lasted a total of 126 hours. The shortest storage period is 26-50 hours and the longest storage period is 126-150 hours.
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Johnson, Lawrence A., Glenn R. Welch y Wim Rens. "The Beltsville sperm sexing technology: high-speed sperm sorting gives improved sperm output for in vitro fertilization and AI". Journal of Animal Science 77, suppl_2 (1999): 213. http://dx.doi.org/10.2527/1999.77suppl_2213x.
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Thabet Saeed, Ghassan, Khalid Suhail A. Al-Azzawi y Hydar Saadi Hassan Al-Wasti. "The Effect of Mechanical Vibration on Human Sperm Activity in Vitro". Biomedical and Pharmacology Journal 11, n.º 3 (11 de julio de 2018): 1617–21. http://dx.doi.org/10.13005/bpj/1529.
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It is well known that sperm is a unique cell in that it has a function to be done by itself outside the body and this function is essential for species' continuity thus sperm by its power and intact structure has to reach the ova and perform the fertilization and this journey is affected by the chemical and physical factors that might increase or decrease its ability to move or fertilize or even to survive. The aim of this study is to find the effect of vibration that is a vigorous movement with high frequency for 20min on whole seminal fluid samples as an external physical factor. 40 fresh seminal fluid samples were selected. 1ml of each semen samples was placed in the bottom of conical tube; the tube was exposure to vibration waves by using a special shaker designed for this purpose for 20 min. This shaker consist of a M540 DC motor equipped with PWM controller to control the rotational speed from 5-2400 rpm. Semen analysis was done before and after subject vibration. A significant increase (P<0.05) was found in percentage of sperm active directed motility (grade A) with a non-significant increase in sluggish motility and a non-significant decrease in percentage of immotile sperms percentage. No significant changes were founded regarded sperm morphology and count. It was concluded that vibrating seminal sample for 20min increases the overall sperms activity with significant increase in percentage of highly active directed sperms.
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Casselman, Stephen J., Albrecht I. Schulte-Hostedde y Robert Montgomerie. "Sperm quality influences male fertilization success in walleye (Sander vitreus)". Canadian Journal of Fisheries and Aquatic Sciences 63, n.º 9 (1 de septiembre de 2006): 2119–25. http://dx.doi.org/10.1139/f06-108.
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We examined how variation in sperm quality influences a male's success at fertilizing ova (male fertilization success) in a wild population of walleye (Sander vitreus). To do this, we conducted controlled fertilization trials using milt and eggs (ova) from wild-spawning fish and measured male fertilization success (percentage of ova fertilized) by examining eggs after 24 h of incubation. We found that both the number of sperm and sperm swimming speed (at 10 s after activation) were significantly related to fertilization success. There was, with respect to fertilization success, a relatively large return on male investment in the number of sperm, but this return diminished as the percentage of ova fertilized increased above 50%. This is in agreement with theoretical predictions based on external fertilization dynamics. When the number of sperm used in the experimental trials was kept constant, variation in sperm swimming speed (at 10 s after activation) explained approximately 90% of the variation in a male's fertilization success. These findings demonstrate that the variation in sperm quality found in wild spawning populations has the potential to dramatically influence male reproductive success.
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Kleven, Oddmund, Frode Fossøy, Terje Laskemoen, Raleigh J. Robertson, Geir Rudolfsen y Jan T. Lifjeld. "COMPARATIVE EVIDENCE FOR THE EVOLUTION OF SPERM SWIMMING SPEED BY SPERM COMPETITION AND FEMALE SPERM STORAGE DURATION IN PASSERINE BIRDS". Evolution 63, n.º 9 (septiembre de 2009): 2466–73. http://dx.doi.org/10.1111/j.1558-5646.2009.00725.x.
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Gomendio, Montserrat, Aurelio F. Malo, Julian Garde y Eduardo R. S. Roldan. "Sperm traits and male fertility in natural populations". Reproduction 134, n.º 1 (julio de 2007): 19–29. http://dx.doi.org/10.1530/rep-07-0143.
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Male fertility has seldom been studied in natural populations because it has been assumed that strong selection would result in uniformly high values among males, and therefore mating success has been equated with fertilisation success. In contrast, male fertility has received much attention in studies of domestic livestock, where economic benefits rely on improving productivity, and in human infertility studies, where the efficiency of treatments depends on understanding which ejaculate traits explain reproductive failures and predict success at assisted conception. Despite years of efforts, no conclusive results have been obtained, probably because such studies have focused on opposite extremes of the range with little variation: domestic livestock have often been subject to strong artificial selection for high fertility, and human patients requiring treatment have compromised fertility. Recent findings from natural populations of red deer have shown that males differ markedly in their fertility, and have revealed the degree of variation found in different semen traits, both between and within males. Fertility trials have shown that male fertility is determined mainly by sperm swimming speed and the proportion of normal sperm, when sperm numbers are kept constant. Sperm design exerts a strong influence on sperm swimming speed, with faster swimming sperm having elongated heads, shorter midpieces and a longer principal plus terminal pieces in relation to total flagellum length. Thus, the large inter-male variation in sperm design found among natural populations underlies differences in sperm swimming speed which, in turn, determine differences in male fertility rates. Secondary sexual characters are honest indicators of male fertility, so males with large and elaborated antlers have larger testes and faster swimming sperm. Testosterone does not seem to mediate the relationship between antler size and semen quality, since it is associated with sperm production, but not with sperm quality or antler size. Finally, more fertile males produce a greater proportion of sons, who will inherit the semen traits which will enhance their fertility.
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Almeida, Diones Bender, Marco André Paldes Costa, Liane Ney Bassini, Cecilia Irene Pérez Calabuig, Carla GiovaneÁvila Moreira, Marília Danyelle Nunes Rodrigues, Antonio Sergio Varela Junior, Carine Dahl Corcini, Maria Eduarda Bicca Dode y Heden Luiz Marques Moreira. "Sperm evaluation in strains of Nile tilapia, Oreochromis niloticus". JOURNAL OF ADVANCES IN AGRICULTURE 6, n.º 2 (28 de julio de 2016): 933–41. http://dx.doi.org/10.24297/jaa.v6i2.5376.
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The reproductive characteristics of tilapia species used for large-scale production is critically important for breeding management. Although Nile tilapia (Oreochromis niloticus) is one of the most cultivated species globally, little is known about its sperm characteristics. Therefore, the objective of this study was to evaluate and compare the reproductive parameters of three tilapia strains before and after cryopreservation. Nile tilapia specimens from three strains, Supreme (SUP), Premium Aquabel (PA), and Chitralada (CHI) (90 specimens in total, 30 from each strain), were examined. All morphometric measurements were highest in PA. CHI had the highest sperm motility and speed, although less than half the sperm concentration of SUP. PA had a similar sperm speed and concentration to CHI, although its sperm motility was similar to that of SUP. SUP had a relatively high sperm viability and higher percentages of sperm without dislocation than PA and CHI. However, all strains showed similar rectilinear dislocation. Except for PA DNA integrity, SUP showed the best results before cryopreservation. From the results it was not possible to identify an ideal marker for semen quality, due to the differences observed between specimens from the same fish. However, the results regarding efficient sperm cryopreservation in the present study are important for the genetic screening and development of these strains in aquaculture.
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Trippel, Edward A. y John D. Neilson. "Fertility and Sperm Quality of Virgin and Repeat-Spawning Atlantic Cod (Gadus morhua) and Associated Hatching Success". Canadian Journal of Fisheries and Aquatic Sciences 49, n.º 10 (1 de octubre de 1992): 2118–27. http://dx.doi.org/10.1139/f92-235.
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Sperm performance of virgin and repeat spawners of Atlantic cod (Gadus morhua) was compared. Our results indicate that sperm extracted from either virgin or repeat-spawning male cod exhibit a high capacity (usually >95%) to fertilize eggs at semen:seawater dilutions ranging from 1:1 to 1:100. Fertilization rates at higher dilutions, however, decreased to averages of 47 and 53% at 1:1000, with no statistically significant differences occurring betwen the two types of spawners. Spermatocrit and proportion of sperm cells exhibiting progressive forward motion together accounted for, at most, 14% of the total variability in success of fertilization at semen:seawater dilutions of 1:250, 1:500, and 1:1000. Individuals of both spawner types had immotile sperm, sometimes at high prevalence levels, but these individuals achieved fertiliztion rates comparable with those with high sperm motility. Hatching success of eggs fertilized by virgin males was more variable but, based on mean values, was almost identical to that of repeat spawners. Use of a video camera to record enlarged images of sperm with a haemacytometer grid pattern in the background has permitted the first documented measurements of sperm swimming speeds of a marine teleost fish; the fastest recorded speed was 1000 μm∙30 s−1.
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Sharma, R. K., S. Vemulapalli, S. Kohn y A. Agarwal. "Effect of Centrifuge Speed, Refrigeration Medium, and Sperm Washing Medium on Cryopreserved Sperm Quality After Thawing". Archives of Andrology 39, n.º 1 (enero de 1997): 33–38. http://dx.doi.org/10.3109/01485019708987899.
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STOLTZ, J. A. y B. D. NEFF. "Sperm competition in a fish with external fertilization: the contribution of sperm number, speed and length". Journal of Evolutionary Biology 19, n.º 6 (noviembre de 2006): 1873–81. http://dx.doi.org/10.1111/j.1420-9101.2006.01165.x.
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Lara, Carlos E., Helen R. Taylor, Benedikt Holtmann, Sheri L. Johnson, Eduardo S. A. Santos, Neil J. Gemmell y Shinichi Nakagawa. "Dunnock social status correlates with sperm speed, but fast sperm does not always equal high fitness". Journal of Evolutionary Biology 33, n.º 8 (21 de junio de 2020): 1139–48. http://dx.doi.org/10.1111/jeb.13655.
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Bennison, Clair, Nicola Hemmings, Jon Slate y Tim Birkhead. "Long sperm fertilize more eggs in a bird". Proceedings of the Royal Society B: Biological Sciences 282, n.º 1799 (22 de enero de 2015): 20141897. http://dx.doi.org/10.1098/rspb.2014.1897.
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Sperm competition, in which the ejaculates of multiple males compete to fertilize a female's ova, results in strong selection on sperm traits. Although sperm size and swimming velocity are known to independently affect fertilization success in certain species, exploring the relationship between sperm length, swimming velocity and fertilization success still remains a challenge. Here, we use the zebra finch ( Taeniopygia guttata ), where sperm size influences sperm swimming velocity, to determine the effect of sperm total length on fertilization success. Sperm competition experiments, in which pairs of males whose sperm differed only in length and swimming speed, revealed that males producing long sperm were more successful in terms of (i) the number of sperm reaching the ova and (ii) fertilizing those ova. Our results reveal that although sperm length is the main factor determining the outcome of sperm competition, complex interactions between male and female reproductive traits may also be important. The mechanisms underlying these interactions are poorly understood, but we suggest that differences in sperm storage and utilization by females may contribute to the outcome of sperm competition.
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Valiuškaitė, Viktorija, Vidas Raudonis, Rytis Maskeliūnas, Robertas Damaševičius y Tomas Krilavičius. "Deep Learning Based Evaluation of Spermatozoid Motility for Artificial Insemination". Sensors 21, n.º 1 (24 de diciembre de 2020): 72. http://dx.doi.org/10.3390/s21010072.
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We propose a deep learning method based on the Region Based Convolutional Neural Networks (R-CNN) architecture for the evaluation of sperm head motility in human semen videos. The neural network performs the segmentation of sperm heads, while the proposed central coordinate tracking algorithm allows us to calculate the movement speed of sperm heads. We have achieved 91.77% (95% CI, 91.11–92.43%) accuracy of sperm head detection on the VISEM (A Multimodal Video Dataset of Human Spermatozoa) sperm sample video dataset. The mean absolute error (MAE) of sperm head vitality prediction was 2.92 (95% CI, 2.46–3.37), while the Pearson correlation between actual and predicted sperm head vitality was 0.969. The results of the experiments presented below will show the applicability of the proposed method to be used in automated artificial insemination workflow.
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Cheng, Chin Yuan y Chao Heng Chien. "Microfluidic Chip of X-Sperm and Y-Sperm Separation by Property and QCM". Applied Mechanics and Materials 378 (agosto de 2013): 594–97. http://dx.doi.org/10.4028/www.scientific.net/amm.378.594.
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In this research, we try to extend the application of bio-chip that basic on our MEMS laboratory like sperm separation for IVF(In Vitro Fertilization). At the past research, many properties of sperm had been observed by academic. The difference between X-sperm and Y-sperm are not only DNA but also like speed of motilitymorphologyweightPH value.[1] Those properties all could be able to promote sperm separation and add to our design for bio-chip. Finally, the end of micro channel had made a DEP-QCM device that was our MEMS laboratory research achievement in the past year. The DEP-QCM device can trapped micro particles or cells and determined weight by the changes of frequency. On the other hand, we also used simulation software on PC to analysis the flow field and electric field for our design.
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Støstad, Hanna Nyborg, Arild Johnsen, Jan Terje Lifjeld y Melissah Rowe. "Sperm head morphology is associated with sperm swimming speed: A comparative study of songbirds using electron microscopy". Evolution 72, n.º 9 (26 de julio de 2018): 1918–32. http://dx.doi.org/10.1111/evo.13555.
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Salinas, Paulo. "Flow Cytometry and Sperm Sexing in Animals". International Journal of Medical and Surgical Sciences 3, n.º 3 (26 de octubre de 2018): 893–902. http://dx.doi.org/10.32457/ijmss.2016.022.
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Flow cytometry is a useful technology in the sexed sperm, which measures and analyzes simultaneously, multiple physical characteristics of the cell, as they flow in a stream flow, through a light beam. The measured properties are the size of a particle, relative internal granularity, relative complexity and relative fluorescence intensity. Currently, hundreds of calves have been gestated through artificial insemination with sexed sperm in animal production. Since 1992, flow cytometry has been used, a technique that allows spermatozoa X and Y differentiation by DNA content. There is no other practical technique for sperm sexing to keep sperm functionality. The objectives of this review are to explain: (1) why the sperm containing the X or Y chromosome are phenotypically similar, but differ among themselves, (2) the principles and procedures used for sexing sperm by flow cytometry and sorting ( 3) accuracy, speed and efficiency of current procedure sperm sexing, (4) sperm damage occurred during sperm sexing and consequently the effects on fertility.
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Hajiyavand, Amir, Mozafar Saadat, Alessandro Abena, Ferhat Sadak y Xiaochen Sun. "Effect of Injection Speed on Oocyte Deformation in ICSI". Micromachines 10, n.º 4 (29 de marzo de 2019): 226. http://dx.doi.org/10.3390/mi10040226.
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Oocyte deformation during injection is a major cause of potential cell damage which can lead to failure in the Intracytoplasmic Sperm Injection (ICSI) operation used as an infertility treatment. Injection speed plays an important role in the deformation creation. In this paper the effect of different speeds on deformation of zebrafish embryos is studied using a specially designed experimental set-up. An analytical model is developed in order to link injection force, deformation, and injection speed. A finite element (FE) model is also developed to analyse the effect of injection speed, allowing the production of additional information that is difficult to obtain experimentally, e.g., deformation and stress fields on the oocyte. The numerical model is validated against experimental results. Experimental results indicate that by increasing the injection speed, the deformation decreases. However, higher speeds cause higher levels of injection force and force fluctuation, leading to a higher vibration during injection. For this reason, an optimum injection speed range is determined. Finally, the FE model was validated against experimental results. The FE model is able to predict the force-deformation variation during injection for different speeds. This proves to be useful for future studies investigating different injection conditions.
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Hook, Kristin A., Lauren M. Wilke y Heidi S. Fisher. "Apical Sperm Hook Morphology Is Linked to Sperm Swimming Performance and Sperm Aggregation in Peromyscus Mice". Cells 10, n.º 9 (1 de septiembre de 2021): 2279. http://dx.doi.org/10.3390/cells10092279.
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Mammals exhibit a tremendous amount of variation in sperm morphology and despite the acknowledgement of sperm structural diversity across taxa, its functional significance remains poorly understood. Of particular interest is the sperm of rodents. While most Eutherian mammal spermatozoa are relatively simple cells with round or paddle-shaped heads, rodent sperm are often more complex and, in many species, display a striking apical hook. The function of the sperm hook remains largely unknown, but it has been hypothesized to have evolved as an adaptation to inter-male sperm competition and thus has been implicated in increased swimming efficiency or in the formation of collective sperm movements. Here we empirically test these hypotheses within a single lineage of Peromyscus rodents, in which closely related species naturally vary in their mating systems, sperm head shapes, and propensity to form sperm aggregates of varying sizes. We performed sperm morphological analyses as well as in vitro analyses of sperm aggregation and motility to examine whether the sperm hook (i) morphologically varies across these species and (ii) associates with sperm competition, aggregation, or motility. We demonstrate inter-specific variation in the sperm hook and then show that hook width negatively associates with sperm aggregation and sperm swimming speed, signifying that larger hooks may be a hindrance to sperm movement within this group of mice. Finally, we confirmed that the sperm hook hinders motility within a subset of Peromyscus leucopus mice that spontaneously produced sperm with no or highly abnormal hooks. Taken together, our findings suggest that any adaptive value of the sperm hook is likely associated with a function other than inter-male sperm competition, such as interaction with ova or cumulous cells during fertilization, or migration through the complex female reproductive tract.
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Nicovich, Philip R., Erin L. Macartney, Renee M. Whan y Angela J. Crean. "Measuring Sperm Movement within the Female Reproductive Tract using Fourier Analysis". Microscopy and Microanalysis 21, n.º 1 (febrero de 2015): 256–63. http://dx.doi.org/10.1017/s1431927614014627.
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AbstractThe adaptive significance of variation in sperm phenotype is still largely unknown, in part due to the difficulties of observing and measuring sperm movement in its natural, selective environment (i.e., within the female reproductive tract). Computer-assisted sperm analysis systems allow objective and accurate measurement of sperm velocity, but rely on being able to track individual sperm, and are therefore unable to measure sperm movement in species where sperm move in trains or bundles. Here we describe a newly developed computational method for measuring sperm movement using Fourier analysis to estimate sperm tail beat frequency. High-speed time-lapse videos of sperm movement within the female tract of the neriid flyTelostylinus angusticolliswere recorded, and a map of beat frequencies generated by converting the periodic signal of an intensity versus time trace at each pixel to the frequency domain using the Fourier transform. We were able to detect small decreases in sperm tail beat frequency over time, indicating the method is sensitive enough to identify consistent differences in sperm movement. Fourier analysis can be applied to a wide range of species and contexts, and should therefore facilitate novel exploration of the causes and consequences of variation in sperm movement.
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Ogneva, Irina V., Maria A. Usik, Nikolay S. Biryukov y Yuliya S. Zhdankina. "Sperm Motility of Mice under Simulated Microgravity and Hypergravity". International Journal of Molecular Sciences 21, n.º 14 (17 de julio de 2020): 5054. http://dx.doi.org/10.3390/ijms21145054.
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For deep space exploration, reproductive health must be maintained to preserve the species. However, the mechanisms underlying the effect of changes in gravity on male germ cells remain poorly understood. The aim of this study was to determine the effect of simulated micro- and hypergravity on mouse sperm motility and the mechanisms of this change. For 1, 3 and 6 h, mouse sperm samples isolated from the caudal epididymis were subjected to simulated microgravity using a random position machine and 2g hypergravity using a centrifuge. The experimental samples were compared with static and dynamic controls. The sperm motility and the percentage of motile sperm were determined using microscopy and video analysis, cell respiration was determined by polarography, the protein content was assessed by Western blotting and the mRNA levels were determined using qRT-PCR. The results indicated that hypergravity conditions led to more significant changes than simulated microgravity conditions: after 1 h, the speed of sperm movement decreased, and after 3 h, the number of motile cells began to decrease. Under the microgravity model, the speed of movement did not change, but the motile spermatozoa decreased after 6 h of exposure. These changes are likely associated with a change in the structure of the microtubule cytoskeleton, and changes in the energy supply are an adaptive reaction to changes in sperm motility.
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Eshel, D., C. Shingyoji, K. Yoshimura, I. R. Gibbons y K. Takahashi. "Evidence for an inequality in the forces that generate principal and reverse bends in sperm flagella". Journal of Cell Science 100, n.º 1 (1 de septiembre de 1991): 213–18. http://dx.doi.org/10.1242/jcs.100.1.213.
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The response of the mechanism initiating flagellar bends to imposed mechanical transients has been studied by holding the head of a sea urchin sperm in the tip of a sinusoidally vibrating micropipet and then displacing the micropipet laterally at a speed of up to 1.15 micron ms-1 for 1.5 beat cycle, without vibration, before resuming sinusoidal vibration with the initial phase, frequency and amplitude at the new location of the pipet. This transient displacement of the micropipet delays the initiation of the bend that was due to initiate 0.5 beat cycle after onset of the displacement. The amount of this delay increases with the speed of the displacement, for speeds up to 1 micron ms-1. Analysis of the flagellar waveforms during the transient showed that with imposed displacements at speeds of equal magnitude, the initiation of a principal bend was delayed to a longer extent than that of a reverse bend. At a micropipet speed of 0.75 micron ms-1, there was an average delay of 0.21 beat cycle in the initiation time of a principal bend as compared to a delay of only about 0.04 beat cycle in the initiation time of a reverse bend during displacements in the opposite direction. For both principal and reverse bends, the second bend due to initiate during the transient displacement initiated in most of the cases with no delay, regardless of the micropipet speed. Our results suggest that the force generated by microtubule sliding to initiated a new reverse bend is greater than that generated to initiate a principal bend.
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Schulte-Hostedde, Albrecht I. y Gary Burness. "Fertilization dynamics of sperm from different male mating tactics in bluegill (Lepomis macrochirus)". Canadian Journal of Zoology 83, n.º 12 (1 de diciembre de 2005): 1638–42. http://dx.doi.org/10.1139/z05-164.
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Sperm competition results in the evolution of ejaculate characteristics such as high sperm density, high motility, and fast sperm swimming speed. A fundamental assumption of sperm competition theory is that ejaculates with high motility and fast-swimming sperm have an advantage with respect to fertilization success. We tested this assumption by studying the fertilization dynamics of alternative mating tactics (cuckolders and parentals) of male bluegill (Lepomis macrochirus Rafinesque, 1819). Sneakers (cuckolders) have faster swimming sperm and a higher proportion of motile sperm immediately following sperm activation than do parentals; however, these variables decline more quickly over time in sneaker sperm than in the sperm of parental males. We used a controlled fertilization experiment to test the prediction that parental males will have higher fertilization success than sneakers late in the sperm activation cycle because of the reduced rate of decline in ejaculate quality over time. We found that as the time from sperm activation increases parental sperm fertilizes more eggs than the sperm of sneakers. Our results support the idea that fertilization success is higher when ejaculates contain a higher proportion of either motile sperm or faster swimming sperm, all else being equal. In addition, after controlling for time from sperm activation, we found a significant bias in fertilization success toward parental males, suggesting that cryptic female choice might play a role in fertilization dynamics.
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Aparicio, I. M., M. J. Bragado, M. C. Gil, M. Garcia-Herreros, L. Gonzalez-Fernandez, J. A. Tapia y L. J. Garcia-Marin. "Porcine sperm motility is regulated by serine phosphorylation of the glycogen synthase kinase-3α". Reproduction 134, n.º 3 (septiembre de 2007): 435–44. http://dx.doi.org/10.1530/rep-06-0388.
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Sperm functions are critically controlled through the phosphorylation state of specific proteins. Glycogen synthase kinase-3 (GSK3) is a serine/threonine kinase with two different isoforms (α and β), the enzyme activity of which is inhibited by serine phosphorylation. Recent studies suggest that GSK3 is involved in the control of bovine sperm motility. Our aim was to investigate whether GSK3 is present in porcine spermatozoa and its role in the function of these cells. This work shows that both isoforms of GSK3 are present in whole cell lysates of porcine sperm and are phosphorylated on serine in spermatozoa stimulated with the cAMP analog, 8Br-cAMP. A parallel increase in serine phosphorylation of the isoform GSK3α, but not in the isoform GSK3β, is observed after treatments that also induce a significant increase in porcine sperm velocity parameters. Therefore, a significant positive correlation among straight-line velocity, circular velocity, average velocity, rapid-speed spermatozoa, and GSK3α serine phosphorylation levels exists. Inhibition of GSK3 activity by alsterpaullone leads to a significant increase in the percentage of rapid- and medium-speed spermatozoa as well as in all sperm velocity parameters and coefficients. Moreover, pretreatment of porcine spermatozoa with alsterpaullone significantly increased the percentage of capacitated porcine spermatozoa and presents no effect in the number of acrosome-reacted porcine spermatozoa. Our work suggests that the isoform GSK3α plays a negative role in the regulation of porcine sperm motility and points out the possibility that sperm motile quality might be modulated according the activity state of GSK3α.
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Omori, Toshihiro y Takuji Ishikawa. "Swimming of Spermatozoa in a Maxwell Fluid". Micromachines 10, n.º 2 (24 de enero de 2019): 78. http://dx.doi.org/10.3390/mi10020078.
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It has been suggested that the swimming mechanism used by spermatozoa could be adopted for self-propelled micro-robots in small environments and potentially applied to biomedical engineering. Mammalian sperm cells must swim through a viscoelastic mucus layer to find the egg cell. Thus, understanding how sperm cells swim through viscoelastic liquids is significant not only for physiology, but also for the design of micro-robots. In this paper, we developed a numerical model of a sperm cell in a linear Maxwell fluid based on the boundary element slender-body theory coupling method. The viscoelastic properties were characterized by the Deborah number (De), and we found that, under the prescribed waveform, the swimming speed decayed with the Deborah number in the small-De regime (De < 1.0). The swimming efficiency was independent of the Deborah number, and the decrease in the swimming speed was not significantly affected by the wave pattern.
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Ladyka, V. I., Y. I. Sklyarenko, Y. M. Pavlenko y O. V. Sherbak. "ANALYSIS OF CRYOСONSERVED SPERM OF SIRES OF THE LEBEDINIAN BREED AND ORIGINAL BROWN CATTLE OF GERMANY". Animal Breeding and Genetics 58 (29 de noviembre de 2019): 95–101. http://dx.doi.org/10.31073/abg.58.13.
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In recent years, in Ukraine, as well as around the world, some local breeds have been on the verge of extinction, resulting in irretrievable loss of valuable genes, reduction of genetic diversity. In order to avoid these problems, it is necessary to work on the conservation of animal genetic resources. The creation of banks for long-term storage of biological material is one of the methods of preserving the gene pool of local, small and indigenous breeds of animals.
Sperm quality is one of the main factors that determines the success of insemination of heifers and cows. Comprehensive analysis of sperm includes a large number of qualitative and quantitative indicators, the accuracy of which is influenced by a number of objective and subjective factors.
Currently, microscopic analysis of sperm motility and survival is used in production conditions. Such approaches are easy to implement, but their results can be subjective. Research using a computer-based sperm fertility analysis system is becoming a priority today. With the help of CASA-Sperm Vision it is possible to carry out a morphological analysis already during the study of sperm motility.
The purpose of our research was to analyze the quality of deep-frozen sperm of sires of Lebedinian breed and original brown cattle of Germany in order to attract such genetic material in the conservation of local Lebedinian breed cattle.
Materials and methods. In the study used cryopreserved sperm doses of five sires of Lebedinian breed and three sires of the original brown cattle of Germany.
Researches of qualitative, quantitative and dynamic characteristics of sperm of bulls were carried out at the laboratory of biotechnology of reproduction of Institute of Animal Breeding and Genetics nd. a. M.V.Zubets of NAAS and production laboratory "Ukrainian genetic company" using computer analysis of sperm motility Sperm Analysis System Version 12 IVOS.
It was determined that the average dose of cryopreserved sperm of bulls of the Lebedinian breed was 0.25 ml, and of the sires of the original brown cattle of Germany -0.21 ml. It was found that the sires of the original brown cattle of Germany had the best indicators of total sperm motility by 21.7% compared to the sires of the Lebedinian breed (55.7%). They also noted a greater number of sperm with straight-forward movement of 16.5%. (40.2% of the Lebedinian breed sires).
The average concentration of sperm in one milliliter was 10.5 times higher in animals of the Lebedinian breed (compared to the sires of the original brown cattle of Germany (331 million/ml).
Comparing the indicators of the average speed of the sperm on the average trajectory (VAP), it should be noted that the minimum value was 85.3 microns/sec, the maximum value for this indicator – 141.7 microns/sec. The results of the VSL study showed that the average value of this indicator of sperm in the studied sperm doses of sires of the Lebedinian breed was 102 microns/sec, of the original brown cattle of Germany – 75.
Obtained opposite to the direction coefficients of the correlation depending on the origin, between total sperm motility and average sperm speed for the average trajectory, the average speed of the sperm on the real trajectory, the average deviation of the sperm, the degree of straightness of the directed movement of sperm.
Summary.
1. The complex of researches provided an objective analysis of qualitative and quantitative indicators of cryopreserved sperm production of the bulls of original brown cattle of Germany and the Lebedinian breed. It was found that the quality of the studied sperm doses met the requirements of "Instructions for Artificial Insemination of Cows and Heifers" (Order of the Ministry of Agrarian Policy of Ukraine dated August 1, 2001 № 230).
2. The comparative analysis of sperm production of the original brown cattle of Germany and the Lebedinian breed for its long-term storage was carried out. It is established that the sperm of sires of the original brown cattle of Germany exhibit higher dynamic characteristics of movement, while the sperm of sires of the Lebedinian breed were inferior to them in these indicators.
3. The possibility of insemination of females with cryopreserved sperm of the studied bulls whose sperm production has been stored for more than 30 years has been proved.
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Tuset, V. M., E. A. Trippel y J. de Monserrat. "Sperm morphology and its influence on swimming speed in Atlantic cod". Journal of Applied Ichthyology 24, n.º 4 (agosto de 2008): 398–405. http://dx.doi.org/10.1111/j.1439-0426.2008.01125.x.
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Parker, T. H., D. Thompson, J. D. Ligon, B. Schneider y F. Byrn. "Does red junglefowl comb size predict sperm swimming speed and motility?" Ethology Ecology & Evolution 18, n.º 1 (enero de 2006): 53–60. http://dx.doi.org/10.1080/08927014.2006.9522726.
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Fisher, Heidi S., Luca Giomi, Hopi E. Hoekstra y L. Mahadevan. "The dynamics of sperm cooperation in a competitive environment". Proceedings of the Royal Society B: Biological Sciences 281, n.º 1790 (7 de septiembre de 2014): 20140296. http://dx.doi.org/10.1098/rspb.2014.0296.
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Sperm cooperation has evolved in a variety of taxa and is often considered a response to sperm competition, yet the benefit of this form of collective movement remains unclear. Here, we use fine-scale imaging and a minimal mathematical model to study sperm aggregation in the rodent genus Peromyscus . We demonstrate that as the number of sperm cells in an aggregate increase, the group moves with more persistent linearity but without increasing speed. This benefit, however, is offset in larger aggregates as the geometry of the group forces sperm to swim against one another. The result is a non-monotonic relationship between aggregate size and average velocity with both a theoretically predicted and empirically observed optimum of six to seven sperm per aggregate. To understand the role of sexual selection in driving these sperm group dynamics, we compared two sister-species with divergent mating systems. We find that sperm of Peromyscus maniculatus (highly promiscuous), which have evolved under intense competition, form optimal-sized aggregates more often than sperm of Peromyscus polionotus (strictly monogamous), which lack competition. Our combined mathematical and experimental study of coordinated sperm movement reveals the importance of geometry, motion and group size on sperm velocity and suggests how these physical variables interact with evolutionary selective pressures to regulate cooperation in competitive environments.
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Smith, Chad C. y Michael J. Ryan. "Tactic-dependent plasticity in ejaculate traits in the swordtail Xiphophorus nigrensis". Biology Letters 7, n.º 5 (20 de abril de 2011): 733–35. http://dx.doi.org/10.1098/rsbl.2011.0286.
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In species with alternative reproductive tactics, males that sneak copulations often have larger, higher quality ejaculates relative to males that defend females or nest sites. Ejaculate traits can, however, exhibit substantial phenotypic plasticity depending on a male's mating role in sperm competition, which may depend on the tactic of his competitor. We tested whether exposure to males of different tactics affected sperm number and quality in the swordtail Xipophorus nigrensis , a species with small males that sneak copulations and large males that court females. Sperm swimming speed was higher when the perceived competitor was small than when the competitor was large. Plasticity, however, was only exhibited by small males. Sperm number and viability were invariant between social environments. Our results suggest sperm quality is role-dependent and that plastic responses to the social environment can differ between male reproductive tactics.
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Dardikman-Yoffe, Gili, Simcha K. Mirsky, Itay Barnea y Natan T. Shaked. "High-resolution 4-D acquisition of freely swimming human sperm cells without staining". Science Advances 6, n.º 15 (abril de 2020): eaay7619. http://dx.doi.org/10.1126/sciadv.aay7619.
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We present a new acquisition method that enables high-resolution, fine-detail full reconstruction of the three-dimensional movement and structure of individual human sperm cells swimming freely. We achieve both retrieval of the three-dimensional refractive-index profile of the sperm head, revealing its fine internal organelles and time-varying orientation, and the detailed four-dimensional localization of the thin, highly-dynamic flagellum of the sperm cell. Live human sperm cells were acquired during free swim using a high-speed off-axis holographic system that does not require any moving elements or cell staining. The reconstruction is based solely on the natural movement of the sperm cell and a novel set of algorithms, enabling the detailed four-dimensional recovery. Using this refractive-index imaging approach, we believe that we have detected an area in the cell that is attributed to the centriole. This method has great potential for both biological assays and clinical use of intact sperm cells.
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Subramani, Elavarasan, Himanish Basu, Shyam Thangaraju, Sucheta Dandekar, Deepak Mathur y Koel Chaudhury. "Rotational Dynamics of Optically Trapped Human Spermatozoa". Scientific World Journal 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/154367.
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Introduction. Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner. As sperm motility is an important criterion for assessing the male fertility potential, this technique is used to study sperm cell motility behavior and rotational dynamics.Methods and Patients. An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls.Results. The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa. The rotational speed of sperm cells from infertile men is observed to be significantly less as compared to controls.Conclusions. Distinguishing normal and abnormal sperm cells on the basis of beat frequency above 5.6 Hz may be an important step in modern reproductive biology to sort and select good quality spermatozoa. The application of laser-assisted technique in biology has the potential to be a valuable tool for assessment of sperm fertilization capacity for improving assisted reproductive technology.
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Green, Christine, Jessica P. Rickard, Simon P. de Graaf y Angela J. Crean. "From One Ejaculate to Another: Transference of Sperm Traits via Seminal Plasma Supplementation in the Ram". Biology 9, n.º 2 (18 de febrero de 2020): 33. http://dx.doi.org/10.3390/biology9020033.
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Males can adjust sperm motility instantaneously in response to the perceived risk of sperm competition. The speed of this response suggests that sperm motility is regulated by changes in seminal plasma rather than changes in the sperm cells themselves. Hence, here we test whether inter-ejaculate variation in seminal plasma can be used to alter sperm quality prior to use in assisted reproductive technologies. We supplemented fresh ejaculates of Merino rams with seminal plasma collected from previous ‘donor’ ejaculates to test whether changes in sperm kinetics were related to the relative quality of donor to focal ejaculates. We found a positive relationship between the change in sperm traits before and after supplementation, and the difference in sperm traits between the donor and focal ejaculate. Hence, sperm motility can be either increased or decreased through the addition of seminal plasma from a superior or inferior ejaculate, respectively. This positive relationship held true even when seminal plasma was added from a previous ejaculate of the same ram, although the slope of the relationship depended on the identity of both the donor and receiver ram. These findings indicate that seminal plasma plays a key role in the control and regulation of sperm kinetics, and that sperm kinetic traits can be transferred from one ejaculate to another through seminal plasma supplementation.
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Ogneva, Irina V., Maria A. Usik, Maria V. Burtseva, Nikolay S. Biryukov, Yuliya S. Zhdankina, Vladimir N. Sychev y Oleg I. Orlov. "Drosophila melanogaster Sperm under Simulated Microgravity and a Hypomagnetic Field: Motility and Cell Respiration". International Journal of Molecular Sciences 21, n.º 17 (20 de agosto de 2020): 5985. http://dx.doi.org/10.3390/ijms21175985.
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The role of the Earth’s gravitational and magnetic fields in the evolution and maintenance of normal processes of various animal species remains unclear. The aim of this work was to determine the effect of simulated microgravity and hypomagnetic conditions for 1, 3, and 6 h on the sperm motility of the fruit fly Drosophila melanogaster. In addition to the usual diet, the groups were administered oral essential phospholipids at a dosage of 500 mg/kg in medium. The speed of the sperm tails was determined by video recording and analysis of the obtained video files, protein content by western blotting, and cell respiration by polarography. The results indicated an increase in the speed of movement of the sperm tails after 6 h in simulated microgravity. The levels of proteins that form the axoneme of the sperm tail did not change, but cellular respiration was altered. A similar effect occurred with the administration of essential phospholipids. These results may be due to a change in the level of phosphorylation of motor proteins. Exposure to hypomagnetic conditions led to a decrease in motility after 6 h against a background of a decrease in the rate of cellular respiration due to complex I of the respiratory chain. This effect was not observed in the flies that received essential phospholipids. However, after 1 h under hypomagnetic conditions, the rate of cellular respiration also increased due to complex I, including that in the sperm of flies receiving essential phospholipids.
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Neff, Anton W., George M. Malacinski y Hae-Moon Chung. "Microgravity simulation as a probe for understanding early Xenopus pattern specification". Development 89, n.º 1 (1 de octubre de 1985): 259–74. http://dx.doi.org/10.1242/dev.89.1.259.
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Pattern specification in early amphibians Xenopus) was monitored in embryos subjected to gravity compensation (microgravity simulation) by constant low-speed rotation on a horizontal axis (clinostat). The useful range of clinostat speeds was determined empirically. The results were interpreted in terms of a set of models which account for the reorganization of the egg cytoplasm that follows fertilization and that correlates with the establishment of dorsal/ventral polarity. Large percentages of clinostated eggs displayed a positive result (normal axial structure morphogenesis). Consequently, normal development of amphibian eggs in the microgravity environment of space should be possible. Models which depend upon gravity-driven rearrangements for cytoplasmic organization (e.g. dorsal/ventral polarization) of the early embryo should, therefore, not be favoured. At several clinostat speeds symmetrization of the egg in accordance with the site of sperm penetration, a natural phenomenon, was altered. The results at those clinostat speeds indicate that models which employ sperm entrance as an obligatory feature of the cytoplasmic rearrangements that generate egg polarity are not applicable.
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Ishijima, Sumio. "Dynamics of flagellar force generated by a hyperactivated spermatozoon". REPRODUCTION 142, n.º 3 (septiembre de 2011): 409–15. http://dx.doi.org/10.1530/rep-10-0445.
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The flagellar force generated by a hyperactivated monkey spermatozoon was evaluated using the resistive force theory applied to the activated (nonhyperactivated) and hyperactivated flagellar waves that were obtained using high-speed video microscopy and digital image processing in order to clarify the mechanism of sperm penetration through the zona pellucida. No difference in the maximum propulsive force, which was parallel to the longitudinal sperm head axis, was found between the activated and hyperactivated spermatozoa. The maximum transverse force (45 pN), which was perpendicular to the longitudinal sperm head axis, of the hyperactivated spermatozoon was ∼2.5 times its propulsive force. As the beat frequency of the flagellar beating remarkably decreased during the hyperactivation, the slowly oscillating transverse force (5 Hz) by the hyperactivated spermatozoon seems to be most effective for sperm penetration through the zona pellucida.
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Frommel, A. Y., V. Stiebens, C. Clemmesen y J. Havenhand. "Effect of ocean acidification on marine fish sperm (Baltic cod: <i>Gadus morhua</i>)". Biogeosciences 7, n.º 12 (1 de diciembre de 2010): 3915–19. http://dx.doi.org/10.5194/bg-7-3915-2010.
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Abstract. Ocean acidification, as a consequence of increasing marine pCO2, may have severe effects on the physiology of marine organisms. However, experimental studies remain scarce, in particular concerning fish. While adults will most likely remain relatively unaffected by changes in seawater pH, early life-history stages are potentially more sensitive – particularly the critical stage of fertilization, in which sperm motility plays a central role. In this study, the effects of ocean acidification (decrease of pHT to 7.55) on sperm motility of Baltic cod, Gadus morhua, were assessed. We found no significant effect of decreased pH on sperm speed, rate of change of direction or percent motility for the population of cod analyzed. We predict that future ocean acidification will probably not pose a problem for sperm behavior, and hence fertilization success, of Baltic cod.
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Frommel, A. Y., V. Stiebens, C. Clemmesen y J. Havenhand. "Effect of ocean acidification on marine fish sperm (Baltic cod: <i>Gadus morhua</i>)". Biogeosciences Discussions 7, n.º 4 (5 de agosto de 2010): 5859–72. http://dx.doi.org/10.5194/bgd-7-5859-2010.
Texto completoResumen
Abstract. Ocean acidification, as a consequence of increasing marine pCO2, may have severe effects on the physiology of marine organisms. However, experimental studies remain scarce, in particular concerning fish. While adults will most likely remain relatively unaffected by changes in seawater pH, early life-history stages are potentially more sensitive – particularly the critical stage of fertilization, in which sperm motility plays a central role. In this study, the effects of ocean acidification (decrease of pH to 7.55) on sperm motility of Baltic cod, Gadus morhua, were assessed. We found no significant effect of decreased pH on sperm speed, rate of change of direction or percent motility for the population of cod analyzed. We predict that future ocean acidification will probably not pose a problem for sperm behavior, and hence fertilization success, of Baltic cod.