Academic literature on the topic 'Follicle development'
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Journal articles on the topic "Follicle development"
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Nie, Ruixue, Xiaotong Zheng, Wenhui Zhang, et al. "Morphological Characteristics and Transcriptome Landscapes of Chicken Follicles during Selective Development." Animals 12, no. 6 (2022): 713. http://dx.doi.org/10.3390/ani12060713.
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Ovarian follicle selection largely depends on the transition of granulosa cells from an undifferentiated to a fully differentiated state, which is accompanied by morphological and functional changes in follicles. The processes and transcriptional regulation of follicles during follicle selection are unclear; we thus used follicles from the prehierarchal to the hierarchal stage to investigate histology, reproductive endocrinology, and transcription. The morphology of follicles changed markedly during follicle selection. The numbers of large white, small yellow, and large yellow follicles (LWF, SYF, and LYF, respectively) were 11.83 ± 2.79, 6.83 ± 2.23, and 1.00, respectively, per ovary. LYF showed thicker granulosa cell layers than those of other prehierarchal follicles. Progesterone concentrations were significantly higher in LYF than that in LWF and SYF. In total, 16,823 genes were positively expressed in LWF, SYF, and LYF. Among follicle types, 1290 differentially expressed genes were enriched regarding cell differentiation, blood vessel morphogenesis, and response to steroid hormones. Candidate genes associated with follicle selection participated in the Wnt signaling pathway, steroid hormone biosynthesis, and the TGF-β signaling pathway. We produced insights into crucial morphological characteristics of transcriptional regulation in follicle development. Our results provide an important basis for revealing the mechanism of follicle selection and potential impact on the poultry industry.
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Kezele, Phillip, and Michael K. Skinner. "Regulation of Ovarian Primordial Follicle Assembly and Development by Estrogen and Progesterone: Endocrine Model of Follicle Assembly." Endocrinology 144, no. 8 (2003): 3329–37. http://dx.doi.org/10.1210/en.2002-0131.
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Abstract The assembly of the developmentally arrested primordial follicle and the subsequent transition of the primordial follicle to the primary follicle are critical processes in normal ovarian physiology that remain to be elucidated. Ovarian follicles do not proliferate and the primordial follicles present in the neonate represent the total number of gametes available to a female throughout her reproductive life. The primordial follicles are oocytes surrounded by less differentiated squamous granulosa cells and are derived from oocyte nests, and primary follicles are oocytes surrounded by a single layer of cuboidal granulosa cells that have initiated follicle development. Abnormalities in primordial follicle assembly, arrest, and development (i.e. primordial to primary follicle transition) can cause pathological conditions such as premature ovarian failure. In this study newborn rat ovaries were cultured for 7 d. The rate of primordial follicle assembly in vivo was identical with the rate in vitro. Interestingly, the rate of primordial follicle transition to the primary follicle was found to be 3 times greater in culture. This abnormal rate of primary follicle development in culture suggests the primordial follicle does not arrest in development as observed in vivo. To investigate this phenomena newborn rat ovaries were cultured in the presence of progesterone, estradiol or calf serum. Estradiol, progesterone, or calf serum significantly reduced the level of initial primordial to primary follicle transition. Approximately 60% of follicles make the primordial to primary follicle transition in control ovaries and about 30% in treated ovaries. Steroids and calf serum had no effect on the primordial to primary follicle transition in ovaries collected and cultured from postnatal 4-d-old rats, suggesting the effects observed are restricted to the initial wave of primordial to primary follicle transition. Interestingly, progesterone was also found to significantly reduce the rate of primordial follicle assembly. All viable oocytes assembled into primordial follicles in control ovaries and approximately 40% remained unassembled in progesterone-treated ovaries. Progesterone was also found to reduce primordial follicle assembly in vivo with 10% of the total follicles remaining unassembled in progesterone injected neonatal animals. Analysis of cellular apoptosis demonstrated that progesterone inhibited the coordinated oocyte apoptosis required for primordial follicle assembly. The hypothesis developed is that high levels of maternal and fetal steroids prevent premature primordial follicle assembly and primordial to primary follicle transition in the embryo. After birth steroid levels fall dramatically and the primordial follicles are free to assemble and initiate development. These observations suggest a novel role for steroids and the maternal-fetal endocrine unit in the control of ovarian primordial follicle assembly and early follicular development.
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Nagashima, Jennifer B., Andrea M. Hill, and Nucharin Songsasen. "In vitro development of mechanically and enzymatically isolated cat ovarian follicles." Reproduction and Fertility 2, no. 1 (2021): 35–46. http://dx.doi.org/10.1530/raf-20-0067.
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Graphical Abstract Isolation of ovarian follicles is a key step in culture systems for large mammalian species to promote the continued growth of follicles beyond the preantral stage in fertility preservation efforts. Still, mechanical isolation methods are user-skill dependent and time-consuming, whereas enzymatic strategies carry increased risk of damaging theca cell layers and the basement membranes. Here, we sought to determine an optimal method to rescue domestic cat (Felis catus) early antral and antral stage follicles from ovarian tissue and to evaluate the influence of isolation strategy on follicle development, survival, and gene expression during 14 days of in vitro culture in alginate hydrogel. Mechanical isolation was compared with 90 min digestion in 0.7 and 1.4 Wünsch units/mL Liberase blendzyme (0.7L and 1.4L, respectively). Mechanical isolation resulted in improved follicle growth and survival, and better antral cavity and theca cell maintenance in vitro, compared with 1.4L (P < 0.05) but displayed higher levels of apoptosis after incubation compared with enzymatically isolated follicles. However, differences in follicle growth and survival were not apparent until 7+ days in vitro. Expressions of CYP19A1, GDF9, LHR, or VEGFA were similar among isolation-strategies. Cultured follicles from all isolation methods displayed reduced STAR expression compared with freshly isolated follicles obtained mechanically or via 0.7L, suggesting that prolonged culture resulted in loss of theca cell presence and/or function. In sum, early antral and antral stage follicle development in vitro is significantly influenced by isolation strategy but not necessarily observable in the absence of extended culture. These results indicate that additional care must be taken in follicle isolation optimizations for genome rescue and fertility preservation efforts. Lay summary The ovary contains hundreds of eggs with only a select few developing from an immature stage through to ovulation over the course of an animal's lifetime. Rescue of eggs from this pool, and the ability to grow them in culture to a mature stage, would be incredibly valuable for fertility preservation efforts in both humans and endangered species. Currently, the isolation of ovarian follicles (eggs with their surrounding helper cells) is a key step in culture systems for large mammalian species, to promote continued growth. Yet, isolation methods may affect the follicle’s future developmental capacity. We evaluated two isolation strategies, mechanical micro-dissection (needle/scalpel blade) and enzymatic digestion (using Liberase blendzyme) on ovaries of domestic cats obtained via routine spay procedures. Mechanically isolated follicles displayed improved growth, survival, and indications of developmental competence in 14-day culture, compared with high concentration (1.4 Wünsch units/mL) enzyme-isolated follicles. However, mechanical isolation was not different from low (0.7 Wünsch units/mL) enzyme for these metrics, or for expression of key genes indicative of follicular cell functions. Further, differences in follicle growth/survival were not apparent until 7+ days in culture. Thus, ovarian follicle isolation strategies influence developmental potential in culture, and extended culture will be required to identify optimal methods for fertility preservation efforts.
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Durlinger, Alexandra L. L., Maria J. G. Gruijters, Piet Kramer, et al. "Anti-Müllerian Hormone Attenuates the Effects of FSH on Follicle Development in the Mouse Ovary." Endocrinology 142, no. 11 (2001): 4891–99. http://dx.doi.org/10.1210/endo.142.11.8486.
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Abstract Although ovarian follicle growth is under the influence of many growth factors and hormones of which FSH remains one of the most prominent regulators. Therefore, factors affecting the sensitivity of ovarian follicles to FSH are also important for follicle growth. The aim of the present study was to investigate whether anti-Müllerian hormone (AMH) has an inhibitory effect on follicle growth by decreasing the sensitivity of ovarian follicles to FSH. Furthermore, the combined action of AMH and FSH on ovarian follicle development was examined. Three different experiments were performed. Using an in vitro follicle culture system it was shown that FSH-stimulated preantral follicle growth is attenuated in the presence of AMH. This observation was confirmed by an in vivo experiment showing that in immature AMH-deficient females, more follicles start to grow under the influence of exogenous FSH than in their wild-type littermates. In a third experiment, examination of the follicle population of 4-month-old wild-type, FSHβ-, AMH-, and AMH-/FSHβ-deficient females revealed that loss of FSH expression has no impact on the number of primordial and preantral follicles, but the loss of inhibitory action of AMH on the recruitment of primordial follicles in AMH-deficient mice is increased in the absence of FSH. In conclusion, these studies show that AMH inhibits FSH-stimulated follicle growth in the mouse, suggesting that AMH is one of the factors determining the sensitivity of ovarian follicles for FSH and that AMH is a dominant regulator of early follicle growth.
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Moore, GPM, N. Jackson, K. Isaacs, and G. Brown. "Development and density of wool follicles in Merino sheep selected for single fibre characteristics." Australian Journal of Agricultural Research 47, no. 8 (1996): 1195. http://dx.doi.org/10.1071/ar9961195.
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Wool follicles are classified into 3 major types: primary (P), original secondary (SO), and derived secondary (SD). They are formed during fetal life as successive waves of initiation pass through the skin. P follicles are the first to be initiated. SO follicles develop between the primaries and are separated from them at non-randomly distributed sites. SD follicles are the last to be initiated and branch from SO and other SD follicles. We have measured the densities of these follicles in 4 lines of sheep selected for different fleece characters. Primary follicle and total follicle densities (NP and NP + NS) were estimated by conventional procedures. The densities of pilary canals were also obtained to provide a measure of Np + NSO. Follicle counts in both adult and fetal animals showed that NP and NP + NSO were relatively constant across the lines. Predominantly, density differences were due to variations in the numbers of follicles initiated during the last wave, forming the derived secondary population. Changes in follicle densities were therefore effected by developmental mechanisms that increase or decrease the extent of branching rather than by altering the numbers of P and SO follicles. The results suggest firstly that the numbers of initiation sites for P or SO follicle formation in the fetus, corresponding to the pilary canals of adult skin, are limited. Secondly, the skin has the capacity to continue to initiate follicles after most or all of the sites have been occupied. It is concluded that the mechanisms controlling follicle initiation site densities and total follicle densities are independently regulated in the sheep. The observations are discussed in relation to factors that influence the densities of the different follicle types. The results have practical implications for changing fleece weight and fibre diameter through selective breeding.
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Cossigny (Rosairo), D. A., J. K. Findlay, and A. E. Drummond. "123. ACTIVIN A AND OVARIAN FOLLICLE DEVELOPMENT." Reproduction, Fertility and Development 21, no. 9 (2009): 42. http://dx.doi.org/10.1071/srb09abs123.
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A significant developmental stage in ovarian folliculogenesis is the acquisition of gonadotropin sensitivity by ovarian follicles. Activin has previously been suggested to be involved in the responsiveness of granulosa cells to FSH (1). Therefore, the role of activin was investigated using a ‘physiological’ culture system to determine if pathways exist to transduce activin signals within the postnatal rat ovary. Organ cultures with day 4 whole ovaries were employed in order to assess the potential impact of Activin A on follicle growth and transition from the primordial through to the primary and later preantral stages of development. Ovaries were isolated and cultured for 10 days with the addition of supplemented DMEM/Hams F-12 media (2)and either FSH (100ng/ml), Activin A (50ng/ml), or a combination of the two. Media and treatments were refreshed every alternate day. At the end of the culture period, ovaries were fixed and sectioned, or placed immediately into Ultraspec for RNA extraction for future real-time PCR. Sections were used for morphological assessment and ovarian follicle counting of primordial, primary and preantral follicles. An evaluation of atresia by the detection of apoptotic cells was undertaken using terminal deoxynucleotidyl transferase (TdT) mediated dUTP-biotin nick-end labeling (TUNEL). Primary follicle numbers increased significantly (P<0.05) in the combined treatment group whereas, preantral follicle numbers increased significantly (P<0.0001) when treated with Activin A alone. This is consistent with a morphological appraisal of atresia where a decrease in atresia was found in primordial and primary follicles, supporting the primary follicle development data and Activin A treatment alone resulted in more healthy primary and preantral follicles than atretic ones. Therefore, a stimulatory role for Activin A both in the presence of FSH (primary follicle development) or alone (preantral follicle development) has resulted in more follicles making the transition from the primordial to primary stages, as well as to the later preantral stages.
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McGee, Elizabeth A., and Aaron J. W. Hsueh. "Initial and Cyclic Recruitment of Ovarian Follicles*." Endocrine Reviews 21, no. 2 (2000): 200–214. http://dx.doi.org/10.1210/edrv.21.2.0394.
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Abstract Mammalian ovaries consist of follicles as basic functional units. The total number of ovarian follicles is determined early in life, and the depletion of this pool leads to reproductive senescence. Each follicle develops to either ovulate or, more likely, to undergo degeneration. The dynamics of ovarian follicle development have interested endocrinologists and developmental biologists for many years. With the advent of assisted reproductive techniques in humans, the possibility of regulating follicle development in vivo and in vitro has gained clinical relevance. In this review, we focus upon key branching points during the development of ovarian follicles as well as factors involved in determining the eventual destiny of individual follicles. We discuss inconsistencies in the literature regarding the definitions of follicle recruitment and selection and propose to name the two major steps of follicle development as initial and cyclic recruitment, respectively. Because some of these disparities have arisen due to differences in the animal systems studied, we also compare the development of the ovarian follicles of both humans and rats. We also review the status of knowledge of several puzzling clinical issues that may provide important clues toward unlocking the mechanisms of follicle development.
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Schauer, S. N., S. D. Sontakke, E. D. Watson, C. L. Esteves, and F. X. Donadeu. "Involvement of miRNAs in equine follicle development." REPRODUCTION 146, no. 3 (2013): 273–82. http://dx.doi.org/10.1530/rep-13-0107.
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Previous evidence fromin vitrostudies suggests specific roles for a subset of miRNAs, including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, and miR-212, in regulating ovarian follicle development. The objective of this study was to determine changes in the levels of these miRNAs in relation to follicle selection, maturation, and ovulation in the monovular equine ovary. In Experiment 1, follicular fluid was aspirated during ovulatory cycles from the dominant (DO) and largest subordinate (S) follicles of an ovulatory wave and the dominant (DA) follicle of a mid-cycle anovulatory wave (n=6 mares). Follicular fluid levels of progesterone and estradiol were lower (P<0.01) in S follicles than in DO follicles, whereas mean levels of IGF1 were lower (P<0.01) in S and DA follicles than in DO follicles. Relative to DO and DA follicles, S follicles had higher (P≤0.01) follicular fluid levels of miR-145 and miR-378. In Experiment 2, follicular fluid and granulosa cells were aspirated from dominant follicles before (DO) and 24 h after (L) administration of an ovulatory dose of hCG (n=5 mares/group). Relative to DO follicles, L follicles had higher follicular fluid levels of progesterone (P=0.05) and lower granulosa cell levels ofCYP19A1andLHCGR(P<0.005). Levels of miR-21, miR-132, miR-212, and miR-224 were increased (P<0.05) in L follicles; this was associated with reduced expression of the putative miRNA targets,PTEN,RASA1, andSMAD4. These novel results may indicate a physiological involvement of miR-21, miR-145, miR-224, miR-378, miR-132, and miR-212 in the regulation of cell survival, steroidogenesis, and differentiation during follicle selection and ovulation in the monovular ovary.
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Feeney, Amanda, Eric Nilsson, and Michael K. Skinner. "Cytokine (IL16) and tyrphostin actions on ovarian primordial follicle development." REPRODUCTION 148, no. 3 (2014): 321–31. http://dx.doi.org/10.1530/rep-14-0246.
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An ovarian follicle is composed of an oocyte and surrounding theca and granulosa cells. Oocytes are stored in an arrested state within primordial follicles until they are signaled to re-initiate development by undergoing primordial-to-primary follicle transition. Previous gene bionetwork analyses of primordial follicle development identified a number of critical cytokine signaling pathways and genes potentially involved in the process. In the current study, candidate regulatory genes and pathways from the gene network analyses were tested for their effects on the formation of primordial follicles (follicle assembly) and on primordial follicle transition using whole ovary organ culture experiments. Observations indicate that the tyrphostin inhibitor (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased follicle assembly significantly, supporting a role for the MAPK signaling pathway in follicle assembly. The cytokine interleukin 16 (IL16) promotes primordial-to-primary follicle transition as compared with the controls, where as Delta-like ligand 4 (DLL4) and WNT-3A treatments have no effect. Immunohistochemical experiments demonstrated the localization of both the cytokine IL16 and its receptor CD4 in the granulosa cells surrounding each oocyte within the ovarian follicle. The tyrphostin LDN193189 (LDN) is an inhibitor of the bone morphogenic protein receptor 1 within the TGFB signaling pathway and was found to promote the primordial-to-primary follicle transition. Observations support the importance of cytokines (i.e., IL16) and cytokine signaling pathways in the regulation of early follicle development. Insights into regulatory factors affecting early primordial follicle development are provided that may associate with ovarian disease and translate to improved therapy in the future.
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Ruoss, Chantelle, Amanda Tadros, Tim O'Shea, Jim McFarlane, and Ghanim Almahbobi. "Ovarian follicle development in Booroola sheep exhibiting impaired bone morphogenetic protein signalling pathway." REPRODUCTION 138, no. 4 (2009): 689–96. http://dx.doi.org/10.1530/rep-09-0190.
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The role of bone morphogenetic proteins (BMPs) in the regulation of ovarian function has been extensively investigated but the mechanism of regulation is not well understood. The aim of this study was to investigate the effect of mutation in the BMP receptor in Booroola sheep on the number of primordial follicles and rate of follicle recruitment in comparison with that in normal merino sheep in vivo. Whole sheep ovaries at the time of birth, 1.5 and 5 years old were collected and processed for the follicle quantification, using computerised stereological methods and statistical analyses. At birth, the total number of primordial follicles in Booroola sheep was significantly lower than in merino sheep. At 1.5 and 5 years, a reversed pattern in favour of Booroola ewes was seen with significantly more primordial follicles than merino. In parallel, the rate of primordial follicle recruitment to developing cohort was substantially lower in Booroola ewes with only 51 and 66% of primordial follicle consumption at 1.5 and 5 years respectively compared to 92 and 97% in merino ewes. On other hand, the mean numbers of developing primary follicles were smaller in Booroola sheep at the time of birth, yet, Booroola ewes possess more primary follicles than merino at 1.5 years. These findings suggest that attenuation of the intraovarian signalling pathway of BMPs may in fact be a successful means of rationalising follicle consumption, preventing unnecessary loss of follicles from the initial primordial follicle pool, hence increasing reproductive longevity and fertility.
Dissertations / Theses on the topic "Follicle development"
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Lo, Belinda. "Investigating follicle development using in vitro technologies." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:9f646f48-bf7c-426e-a6b0-1d6e8f0f5adc.
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Patients with dysfunctional ovaries, such as those with premature ovarian insufficiency and granulosa cell tumours, do not have normal follicle development and may not respond to traditional assisted reproductive techniques. Using the reaggregated ovary (RO) technique, these patients' oocytes may be reaggregated with functional supporting cells and cultured in vitro to develop fertilisable eggs. However, current research using ROs have only used murine ovaries as a somatic cell source. In this thesis, with the aim of moving towards a clinical treatment, we assessed follicle development in ROs in vitro and progressed to using the technique with human tissues. To assess whether an older murine somatic cell source resulted in advanced follicle development, and how follicle development differed between transplanted and cultured ROs, ROs were generated using postnatal day 2 (P2) and P6 mouse ovaries. To investigate theca cell development in follicles from cultured tissue, mouse ovaries were cultured with mouse serum or encapsulated in hyaluronan hydrogels. Prior to generating and culturing chimeric human-mouse ROs (HuMoROs), competent handling and digestion of bovine cortical tissue was required. Broadly, ROs generated from both P2 and P6 exhibited similar follicle development in vitro after 14 d of culture, and follicles from cultured ROs were more developed than those from transplanted ROs. Theca cell development observed in follicles from cultured ovaries was still poorer than those from in vivo ovaries, even when ovaries were cultured in mouse serum or encapsulated in a hyaluronan hydrogel. Finally, some follicles containing potential human oocytes developed within the generated HuMoROs after 7 d of culture. These results have highlighted the potential of the RO technique as a method to generate fertilisable eggs and identified further aspects which need to be targeted in order to improve the success of the technique.
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Webber, Lisa Jan. "Prenatal follicle development in normal and polycystic ovaries." Thesis, Imperial College London, 2005. http://hdl.handle.net/10044/1/11954.
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Kanakkaparambil, Raji. "Methyl metabolism and ovarian follicle development in sheep." Thesis, University of Nottingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.478930.
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Miller, Andrew Thomas. "Control of follicle growth and development in pigs." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387658.
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Ralph, John Hunter. "Factors affecting follicle and oocyte development in cattle." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/11889.
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The mechanisms governing development of mammalian oocytes are not well understood. Isolation and in vitro growth of immature cattle follicles will enable determination of the factors affecting bovine follicular development, have potential applications in assisted reproduction and provide a suitable model for studying human infertility. Intercommunication of the oocyte and somatic cells is necessary for normal oocyte and follicle development. Studies using systems where oocyte-somatic cell communication is preserved allows an accurate assessment of the factors affecting follicular development. The aims of this project were to examine early follicle and oocyte development in cattle and determine whether the bovine oocyte plays a role in follicular development. A non-enzymatic isolation procedure was developed which allowed intact bovine follicles to be isolated. On the basis of follicle size, these could be divided into 3 distinct stages: large preantral, large preantral/early antral and antral follicles. A culture technique was devised which supported in vitro follicle and oocyte development, the key elements of which were: volume of medium (0.25 ml/follicle), serum and insulin minimal number of medium changes and a substrate of collagen. The effect of FSH on preantral to early antral follicles in culture was examined. Initial experiments on large preantral/early antral follicle growth found that all FSH doses stimulated an increase in follicle diameter. The dose of FSH was important as low levels did not stimulate proliferation or affect oocyte size whilst high levels reduced proliferation, inhibited oocyte growth and reduced oocyte quality. Oocyte localised granulosa cell proliferation was observed in some follicles only when a healthy oocyte was present, demonstrating the importance of oocyte-somatic cell communication in granulosa cell proliferation and differentiation. The intensity of oocyte localised proliferation was reduced at high FSH doses, confirming its dose dependent inhibitory effect on follicular development. FSH stimulated the growth of large preantral/early antral and antral follicles but not oocyte growth in any of the stages. The increase in size was due to an increase in intercellular spacing and, as antral cavities were neither maintained or formed during culture, this may be analogous to antrum development. FSH maintained granulosa cell proliferation in all follicle size classes. No detectable effect of FSH on preantral follicles were found, therefore the effect of FSH depends on the stage of follicle examined.
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Boland, Nicola I. "Experimental investigation of follicle development in mammalian ovaries." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/20104.
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Follicle development in the mouse ovary has been studied using two experimental approaches: firstly, a novel culture system was designed to investigate the metabolism of individual follicles for the first time, and secondly, chimaeric mice and molecular biology techniques were employed to study follicle morphogenesis and the developmental relationships between the different ovarian cell types. Physiological studies of follicle metabolism have been limited by the absence of a suitable culture system which is capable of supporting normal follicle growth and maturation. A novel culture system was developed to provide a physiological model for studies of metabolism by individual mouse ovarian follicles. This system supports the growth of individual primary mouse follicles to Graafian stages <i>in vitro</i> over a period of 5 days and is the first model demonstrating apparently normal ovulation of <i>in vitro</i>-grown follicles in response to LH. Preantral follicles of c.180 microns diameter were micro-dissected from the ovaries of 4 week old mice using fine needles and cultured individually in 20 μl of medium under mineral oil in V-shaped wells of a microtitre plate for a period of 6 days. Medium was supplemented with 1IU/ml hFSH and 5% serum from hypogonadal (<i>hpg/hpg</i>) mice. After every 24 hours of culture, follicles were washed and transferred to wells containing 20 μl of fresh medium: samples of 5-10 μl were then taken from the previous well for the analysis of metabolites. During growth and ovulation in culture, follicles and oocytes were morphologically indistinguishable from those during culture, indicating that premature luteinization does not occur in this system. Approximately 60% of dissected follicles reach preovulatory sizes during culture, which is considerably greater than the maturation rate <i>in vivo</i>, indicating that atresia is not a pre-programmed event. Experiments demonstrated that FSH-stimulation is required for full antral development and LH-induced ovulation, confirming that FSH confers LH-responsiveness to the follicle.
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Harris, Susan Jane. "Properties of Vibrissa follicle cells during follicle development and regeneration, and their interactions with embryonic stem cells." Thesis, Durham University, 2001. http://etheses.dur.ac.uk/3815/.
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Follicular dermal cells possess properties that regulate induction of follicle formation, hair growth, and follicle end bulb regeneration after amputation. While the molecular basis for these developmental interactions are being uncovered, it is evident that innervation, pigmentation and vascular! sation of the follicle, together with its role as a stem cell repository, make interpretations of molecular function within the follicle, complex. This thesis examined aspects of vibrissa follicle development using immunohistochemistry, and demonstrated that segregation of the follicle dermis and epithelial differentiation were defined by lamin-A antibody. Versican, a proteoglycan recently implicated in dermal papilla induction, was absent from early dermal condensations, but its expression correlated with follicle innervation during development and the adult hair growth cycle. When lower follicle regeneration was studied with in situ hybridisation and immunohistochemistry, versican showed two distinct expression domains. These were the dermal components of the end bulb and the follicle neck. BrdU labelling of cell division showed regeneration of the epithelial component to be consistent with stem cell location. Paucity of dermal cell proliferation left the precise origin of the new dermal papilla unresolved, but a-smooth muscle actin expression showed that dermal sheath cells moved through the glassy membrane. Sonic hedgehog expression indicated that epithelial-mesenchymal interactions, evident in follicle development, were mirrored in regeneration. A co-culture model investigated the capacity of follicular dermal cells to induce embryonic stem (ES) cell differentiation. Unexpectedly, follicle cells were seen to maintain ES cells in an undifferentiated condition. Differentiation assays demonstrated that ES cells remained pluripotent after co-culture, lnterleukin-6 family cytokines, known to maintain ES cell pluripotency, were detected by RT-PCR in cultured cells and vibrissa follicles. Thus, since the follicle dermis produces these cytokines, they may be acting to inhibit the differentiation of follicular epithelial stem cells and/or maintain multipotent stem cell populations in the follicle.
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Basiouni, Ghazi Faisal. "Preovulatory follicle development and defective luteal function in sheep." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262149.
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Shuttleworth, Gail. "Porcine ovarian follicle development and the renin-angiotensin system." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324699.
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Miranda, Benjamin H. "Development of a novel, clinically-relevant model for investigating factors that stimulate human hair growth." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5731.
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Lack of hair due to alopecia or skin grafting procedures causes significant distress due to hair's role in social and sexual communication. Only limited pharmacological agents are currently available to stimulate hair growth; their development is hampered by inappropriate model systems. Most research involves large terminal scalp follicles rather than the clinical targets of tiny vellus or intermediate follicles. The overall aim of this thesis was to develop a novel model system based on intermediate hair follicles. Initially, intermediate follicles from female pre-auricular skin were characterised and compared to matched terminal follicles. Intermediate follicles were smaller, less pigmented, shorter and possessed a more 'tubular' bulb morphology than their more 'bulbous' terminal counterparts. Significant correlations were demonstrated between various hair follicle measurements and corresponding dermal papilla diameters. Isolated terminal follicles grew significantly more than intermediate hair follicles in organ culture for 9 days. Testosterone (10nM), the major regulator of human hair growth, increased only intermediate follicle growth; the anti-androgen, cyproterone acetate (1μM), prevented this stimulation, unlike the 5α-reductase type 2 inhibitor finasteride (40ng/ml). Immunohistochemistry demonstrated androgen receptor and 5α-reductase type 2 proteins in both follicle types, while quantitative real-time PCR and gene microarray analysis detected their increased gene expression in intermediate follicles. Thus, smaller intermediate follicles showed major morphological and gene expression differences to terminal follicles in vivo and retained significant, biologically-relevant differences in vitro in organ culture including androgen-responsiveness. Therefore, intermediate hair follicles offer a novel, exciting, more clinically relevant, albeit technically difficult, model for future investigations into hair growth.
Books on the topic "Follicle development"
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F, Naftolin, and DeCherney Alan H, eds. The Control of follicle development, ovulation, and luteal function: Lessons from in vitro fertilization. Raven Press, 1987.
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Duchens, Mario. Influence of suprabasal progesterone on preovulatory follicle development in heifers: Clinical, endocrinologicaland morphological studies. Sveriges Lantbruksuniversitet, 1995.
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Bendell, James John *. Transforming growth factor in the ovarian follicle: production, regulation, and role in growth and development. 1991.
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Garzo-Toro, Vicente Gabriel. Aromatase activity in human granulosa cells during follicular development and the modulation by follicle-stimulating hormone and insulin. 1985.
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Naftolin, Frederick. The Control of Follicle Development, Ovulation, and Luteal Function: Lessons from in Vitro Fertilization (Serono Symposia Publications from Raven, 3). Raven Pr, 1987.
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Schoot. Exogenous Fsh and Development of Human Ovarian Follicles. Parthenon Pub Group, 1995.
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A. Bulbul, Tuba Bulbul, V. Ozdemir, M.S. Akosman, Elmas Ulutas, and O. Yilmaz. Biphasic effect of nitric oxide on development of ovarian primordial and primary follicles in laying quail. Verlag Eugen Ulmer, 2015. http://dx.doi.org/10.1399/eps.2015.105.
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Martin, Daniel. The Enduring Cult of The Bride with White Hair: Chivalry and the Monstrous Other in the Hong Kong Fantasy-Horror. Edinburgh University Press, 2018. http://dx.doi.org/10.3366/edinburgh/9781474424592.003.0005.
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The Bride with White Hair (Ronny Yu, 1993) tells the tale of a heroic swordsman’s ill-fated love affair with a woman transformed by hatred into a white-haired killer, elevated the figure of the frosty-follicled executioner into one of the most enduring icons of the Hong Kong horror film. The timelessness and mysticism of the story lends itself to a highly hybridized type of horror, offering wuxia (swordplay), magical fantasy, romance and erotic scintillation alongside bloody fights, savage violence, and a monstrous depiction of malevolent conjoined twins. This chapter examines this film as emblematic of a particular cultural moment in the development of the Hong Kong fantasy-horror, appealing to a global fanbase for its supposedly transgressive and erotic content, and analyses the film in terms of its generic hybridity, its depictions of disability and morality, as well as in the context of the international marketing and reception of cult Hong Kong horror of the 1990s.
Book chapters on the topic "Follicle development"
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Soriano, Adrianna, Christopher Petit, Savannah Ryan, and Jennifer C. Jemc. "Tracking Follicle Cell Development." In Methods in Molecular Biology. Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-2970-3_8.
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Fauser, Bart C. J. M., Thierry D. Pache, and Dick C. Schoot. "Dynamics of Human Follicle Development." In Ovarian Cell Interactions. Springer New York, 1993. http://dx.doi.org/10.1007/978-1-4613-8336-9_11.
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Niikura, Yuichi, and Joshua Johnson. "Ovarian Follicle Development and Fertility Preservation." In Fertility Preservation in Females. Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4614-5617-9_3.
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Niikura, Yuichi, and Joshua Johnson. "Ovarian Follicle Development and Fertility Preservation." In Fertility Preservation. Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-1783-6_3.
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Hillensjö, Torbjörn, Jan-Henrik Olsson, and Lars Hamberger. "Physiology of Follicle Development in Stimulated Cycles." In Advances in Assisted Reproductive Technologies. Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0645-0_5.
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Gougeon, Alain. "Dynamics of Follicle Development in the Human Ovary." In Polycystic Ovary Syndrome. Springer New York, 1996. http://dx.doi.org/10.1007/978-1-4613-8483-0_2.
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Nishimura, Hisao, Noriko Nishimura, Chiharu Tohyama, Graham R. Cam, and David L. Adelson. "Metallothionein expression during wool follicle development in foetal sheep." In Metallothionein IV. Birkhäuser Basel, 1999. http://dx.doi.org/10.1007/978-3-0348-8847-9_46.
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Schomberg, David W. "Regulation of Follicle Development by Gonadotropins and Growth Factors." In The Primate Ovary. Springer US, 1987. http://dx.doi.org/10.1007/978-1-4615-9513-7_2.
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Noort, Marjolein Hage-van, Wooter C. Puijk, Wim M. M. Schaaper, et al. "Development of Antagonists and Agonists of Follicle Stimulating Hormone." In Spermatogenesis — Fertilization — Contraception. Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-662-02815-5_3.
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Stouffer, Richard L., Mary B. Zelinski-Wooten, Yasmin Aladin Chandrasekher, and Don P. Wolf. "Stimulation of Follicle and Oocyte Development in Macaques for IVF Procedures." In In Vitro Fertilization and Embryo Transfer in Primates. Springer New York, 1993. http://dx.doi.org/10.1007/978-1-4612-2716-8_8.
Full textConference papers on the topic "Follicle development"
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Srinualchai, Phasin, Thanchanok Khorporn, Patsawee Sriboonaied, and Peerapat Thongnuek. "Development of Hair Follicle Dermal Papilla Spheroids Encapsulated in Alginate Hydrogel with Extracellular Matrix Protein." In 2024 16th Biomedical Engineering International Conference (BMEiCON). IEEE, 2024. https://doi.org/10.1109/bmeicon64021.2024.10896310.
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Sarty, Gordon E., Milan Sonka, Weidong Liang, and Roger A. Pierson. "Development of an automatic follicle isolation tool for ovarian ultrasonographic images." In Medical Imaging 1997, edited by Kenneth M. Hanson. SPIE, 1997. http://dx.doi.org/10.1117/12.274170.
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Zhang, Xin, Ruonan Zheng, Jinwen Lin, Yanru Zeng, and Yuming Zheng. "Development of AI Hair Follicle Detecting System and Related Biomedical Products." In 2021 International Conference on Networking Systems of AI (INSAI). IEEE, 2021. http://dx.doi.org/10.1109/insai54028.2021.00019.
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Amaral, Marcello Magri, Aixia Sun, Yilin Li, Ping Wang, Zexu Jiao, and Chao Zhou. "Study of Mice Ovaries using Optical Coherence Tomography." In Latin America Optics and Photonics Conference. Optica Publishing Group, 2022. http://dx.doi.org/10.1364/laop.2022.tu1b.5.
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We investigate the age-related follicle and oocyte morphological differences using Optical Coherence Tomography (OCT). The oocyte’s development stages were observed and discussed. OCT technique can provide a real-time imaging tool for future ovarian tissue characterization.
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Perera, K. U. E., L. Organ, S. Royce, et al. "A Comparison of Secondary Lymphoid Follicle Development in Two Animal Models of Pulmonary Fibrosis." In American Thoracic Society 2020 International Conference, May 15-20, 2020 - Philadelphia, PA. American Thoracic Society, 2020. http://dx.doi.org/10.1164/ajrccm-conference.2020.201.1_meetingabstracts.a2274.
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Al-Rubaei, Hashim M., and Marwa M. Radhi. "Study of the relationship between follicle size and some hormonal and ionic components of ovarian follicular fluid with oocyte development in local goats (Capra hircus)." In 1ST INTERNATIONAL CONFERENCE ON ACHIEVING THE SUSTAINABLE DEVELOPMENT GOALS. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0136163.
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Park, Heuijoon, Sonali Lad, Kelsey Boland, et al. "Abstract LB-039: Chronic inflammation-mediated contribution of bone marrow-derived epithelial cells and hair follicle stem cells to development of cutaneous neoplasms." In Proceedings: AACR Annual Meeting 2019; March 29-April 3, 2019; Atlanta, GA. American Association for Cancer Research, 2019. http://dx.doi.org/10.1158/1538-7445.sabcs18-lb-039.
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Park, Heuijoon, Sonali Lad, Kelsey Boland, et al. "Abstract LB-039: Chronic inflammation-mediated contribution of bone marrow-derived epithelial cells and hair follicle stem cells to development of cutaneous neoplasms." In Proceedings: AACR Annual Meeting 2019; March 29-April 3, 2019; Atlanta, GA. American Association for Cancer Research, 2019. http://dx.doi.org/10.1158/1538-7445.am2019-lb-039.
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Sand, Jordan M., Nancy E. Dreckschmidt, Deric L. Wheeler, Terry D. Oberley та Ajit K. Verma. "Abstract 5151: Protein kinase Cε, which is linked to development of squamous cell carcinomas, potentiates ultraviolet radiation-induced proliferation of hair follicle putative stem cells". У Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC. American Association for Cancer Research, 2010. http://dx.doi.org/10.1158/1538-7445.am10-5151.
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Redding, Gabe P., and John E. Bronlund. "Engineering as a Tool in Assisted Reproduction: An Investigation Using Mathematical Modelling of Oxygen Transport in the Ovarian Follicle." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-66519.
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The key objective of any Assisted Reproductive Technology (ART) is to provide infertile couples with the maximal chance of producing healthy offspring and there is a large body of research within this field directed toward this objective. However, despite this volume of research attention, the success rates of many procedures such as In-Vitro fertilization (IVF) have improved little since their inception. Engineering principles have not been widely applied to ART and, as a result, it appears that there is great potential for engineering to make a contribution to this field. The objectives of this work were to demonstrate the usefulness of engineering principles in this field via the example of modelling oxygen transport in the preovulatory human ovarian follicle. The results show mathematical relationships between follicular fluid dissolved oxygen levels, follicular vascularity and the developmental potential of the oocyte can be described. These relationships are shown to be consistent with findings reported in the literature. Significant results include the emergence of cut off levels of both follicular vascularity and follicle size below which all eggs will be starved of oxygen. Based on current model parameters these cut off levels are predicted to range from 22–40% and 3.5–4.3 ml (19.0–20.3 mm follicle diameter) for follicle vascularity and volume respectively. These results serve to highlight the potential contribution of engineering in general to ART. The implications of these findings are also discussed as are future improvements for modelling mass transport in the ovarian follicle.
Reports on the topic "Follicle development"
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Wang, Xinrun, Tianye Li, Xuechai Bai, Yun Zhu, and Meiliang Zhang. Therapeutic prospect on umbilical cord mesenchymal stem cells in animal model with primary ovarian insufficiency: A meta-analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, 2023. http://dx.doi.org/10.37766/inplasy2023.5.0075.
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Review question / Objective: Participants: experiment POI animal models; Interventions: human umbilical cord mesenchymal stem cells; Comparisons: POI animal models without hUCMSC therapy; Outcomes: estrous cycle situation, serum sex hormone level and ovarian follicle count; Studies: randomized controlled animal study; The aim of the review is to figure out whether hUCMSC can recover ovarian function in POI animal models. Condition being studied: Primary ovarian insufficiency (POI) is a syndrome characterized by reduced or absent ovarian function (hypogonadism) and elevated levels of gonadotropins, specifically luteinising hormone (LH) and follicle-stimulating hormone (FSH). Etiologies of POI are various. Genetic disorders, autoimmune diseases, iatrogenic injuries like chemotherapy and radiotherapy, and infectious diseases all contribute to the development of POI. Main manifestation of POI includes decreased ovarian function and infertility. Patients may suffer from menopausal symptoms, such as increased cardiovascular disease, decreased bone mineral density, vulvovaginal atrophy, psychological distress and so on. Current treatment of POI is limited. HRT mainly ameliorates symptoms while ART can achieve fertility in some patients but faces many challenges in clinical practice because it's hard to get satisfied oocytes. Stem cell therapy is proved to be efficient in recovering organ functions and hUCMSC is one of the easiest cell to obtain. So we think hUCMSC is promising in treating POI.
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Wolfenson, David, William W. Thatcher, and James E. Kinder. Regulation of LH Secretion in the Periovulatory Period as a Strategy to Enhance Ovarian Function and Fertility in Dairy and Beef Cows. United States Department of Agriculture, 2003. http://dx.doi.org/10.32747/2003.7586458.bard.
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The general research objective was to increase herd pregnancy rates by enhancing corpus luteum (CL) function and optimizing follicle development, in order to increase conception rate and embryo survival. The specific objectives were: to determine the effect of the duration of the preovulatory LH surge on CL function; to determine the function of LH during the postovulatory period on CL development; to optimize CL differentiation and follicle development by means of a biodegradable GnRH implant; to test whether optimization of CL development and follicle dynamics in timed- insemination protocols would improve fertility in high-yielding dairy cows. Low fertility in cattle results in losses of hundreds of millions of dollars in the USA and Israel. Two major causes of low fertility are formation of a functionally impaired CL, and subsequent enhanced ovarian follicle development. A functionally impaired CL may result from suboptimal LH secretion. The two major causes of low fertility in dairy cattle in US and Israel are negative energy status and summer heat stress; in both situations, low fertility is associated with reductions in LH secretion and impaired development of the ovulatory follicle and of the CL. In Florida, the use of 450-mg deslorelin (GnRH analogue) implants to induce ovulation, under the Ovsynch protocol resulted in a higher pregnancy rates than use of 750-mg implants, and pregnancy losses tended to decrease compared to controls, due probably to decrease in follicular development and estradiol secretion at the time of conceptus signaling to maintain the CL. An alternative strategy to enhance progesterone concentrations involved induction of an accessory CL by injection of hCG on day 5 after the cows were inseminated. Treatment with hCG resulted in 86% of the cows having two CLs, compared with 23% of the control cows. Conception rates were higher among the hCG-treated cows than among the controls. Another approach was to replace the second injection of GnRH analogue, in a timed-insemination protocol, with estradiol cypionate (ECP) injected 24 h after the injection of PGF₂ₐ Pregnancy rates were comparable with those obtained under the regular Ovsynch (timed- AI) program. Use of ECP induced estrus, and cows inseminated at detected estrus are indeed more fertile than those not in estrus at the time of insemination. Collectively, the BARD-supported programs at the University of Florida have improved timed insemination programs. In Ohio, the importance of the frequency of LH episodes during the early stages of the estrous cycle of cattle, when the corpus luteum is developing, was studied in an in vivo experiment in which cows were subjected to various episodic exposures to exogenous bovine LH. Results indicate that the frequent LH episodes immediately following the time of ovulation are important in development of the corpus luteum, from the points of view of both size and functionality. In another study, rates of cell proliferation and numbers of endothelial cells were examined in vitro in CLs collected from cows that received post-ovulation pulsatile LH treatment at various frequencies. The results indicate that the corpora lutea growth that results from luteal cell proliferation is enhanced by the episodes of LH release that occur immediately after the time of ovulation in cattle. The results also show that luteal endothelial cell numbers did not differ among cows treated with different LH doses. In Israel. a longer duration of the preovulatory LH surge stimulated the steroidogenic capacity of granulosa-derived luteal cells, and might, thereby, contribute to a higher progesterone output from the bovine corpus luteum. In an in vivo study, a subgroup of high-yielding dairy cows with extended estrus to ovulation interval was identified. Associated with this extended interval were: low plasma progesterone and estradiol concentrations and a low preovulatory LH surge prior to ovulation, as well as low post- ovulation progesterone concentration. In experiments based on the above results, we found that injection of GnRH at the onset of estrus increased the LHpeak, prevented late ovulation, decreased the variability between cows and elicited high and uniform progesterone levels after ovulation. GnRH at estrus onset increased conception rates, especially in the summer, and among primiparous cows and those with low body condition. Another study compared ovarian functions in multiparous lactating cows with those in nulliparous non-lactating heifers. The results revealed differences in ovarian follicular dynamics, and in plasma concentrations of steroids and gonadotropins that may account for the differences in fertility between heifers and cows.
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Chen, Yuqi. Efficacy of acupuncture treatment for ovulatory disorder infertility A systematic review and meta-analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, 2023. http://dx.doi.org/10.37766/inplasy2023.4.0088.
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Review question / Objective: Efficacy of Acupuncture for ovulatory disorder infertility: A Systematic Review and Meta-Analysis of randomized controlled trials. Condition being studied: Those who do not have contraception after marriage, have a normal sexual life, and cohabitation for 1 year without pregnancy are called infertility, and those who have no history of pregnancy are called primary infertility. Those with a history of previous pregnancy are called secondary infertility. Infertility is a global reproductive health problem that affects about 10% of married women. Ovulatory infertility ranked second only to fallopian tube abnormalities in the proportion of all infertility, accounting for 25%-30%. Ovulation induction drugs are commonly used in western medicine, but long-term use often causes side effects such as follicular hyperstimulation. Modern clinical studies have shown that traditional Chinese medicine and acupuncture have good effects on follicle development and ovulation induction, with few side effects. This article systematically reviews the clinical efficacy of acupuncture and moxibustion in the treatment of ovulatory infertility by searching the clinical research literature and conducting Meta-analysis, so as to provide an evidence-based basis for clinical decision-making.
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Meidan, Rina, and Robert Milvae. Regulation of Bovine Corpus Luteum Function. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7604935.bard.
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The main goal of this research plan was to elucidate regulatory mechanisms controlling the development, function of the bovine corpus luteum (CL). The CL contains two different sterodigenic cell types and therefore it was necessary to obtain pure cell population. A system was developed in which granulosa and theca interna cells, isolated from a preovulatory follicle, acquired characteristics typical of large (LL) and small (SL) luteal cells, respectively, as judged by several biochemical and morphological criteria. Experiments were conducted to determine the effects of granulosa cells removal on subsequent CL function, the results obtained support the concept that granulosa cells make a substaintial contribution to the output of progesterone by the cyclic CL but may have a limited role in determining the functional lifespan of the CL. This experimental model was also used to better understand the contribution of follicular granulosa cells to subsequent luteal SCC mRNA expression. The mitochondrial cytochrome side-chain cleavage enzyme (SCC), which converts cholesterol to pregnenolone, is the first and rate-limiting enzyme of the steroidogenic pathway. Experiments were conducted to characterize the gene expression of P450scc in bovine CL. Levels of P450scc mRNA were higher during mid-luteal phase than in either the early or late luteal phases. PGF 2a injection decreased luteal P450scc mRNA in a time-dependent manner; levels were significantly reduced by 2h after treatment. CLs obtained from heifers on day 8 of the estrous cycle which had granulosa cells removed had a 45% reduction in the levels of mRNA for SCC enzymes as well as a 78% reduction in the numbers of LL cells. To characterize SCC expression in each steroidogenic cell type we utilized pure cell populations. Upon luteinization, LL expressed 2-3 fold higher amounts of both SCC enzymes mRNAs than SL. Moreover, eight days after stimulant removal, LL retained their P4 production capacity, expressed P450scc mRNA and contained this protein. In our attempts to establish the in vitro luteinization model, we had to select the prevulatory and pre-gonadotropin surge follicles. The ratio of estradiol:P4 which is often used was unreliable since P4 levels are high in atretic follicles and also in preovulatory post-gonadotropin follicles. We have therefore examined whether oxytocin (OT) levels in follicular fluids could enhance our ability to correctly and easily define follicular status. Based on E2 and OT concentrations in follicular fluids we could more accurately identify follicles that are preovulatory and post gonadotropin surge. Next we studied OT biosynthesis in granulosa cells, cells which were incubated with forskolin contained stores of the precursor indicating that forskolin (which mimics gonadotropin action) is an effective stimulator of OT biosynthesis and release. While studying in vitro luteinization, we noticed that IGF-I induced effects were not identical to those induced by insulin despite the fact that megadoses of insulin were used. This was the first indication that the cells may secrete IGF binding protein(s) which regonize IGFs and not insulin. In a detailed study involving several techniques, we characterized the species of IGF binding proteins secreted by luteal cells. The effects of exogenous polyunsaturated fatty acids and arachidonic acid on the production of P4 and prostanoids by dispersed bovine luteal cells was examined. The addition of eicosapentaenoic acid and arachidonic acid resulted in a dose-dependent reduction in basal and LH-stimulated biosynthesis of P4 and PGI2 and an increase in production of PGF 2a and 5-HETE production. Indomethacin, an inhibitor of arachidonic acid metabolism via the production of 5-HETE was unaffected. Results of these experiments suggest that the inhibitory effect of arachidonic acid on the biosynthesis of luteal P4 is due to either a direct action of arachidonic acid, or its conversion to 5-HETE via the lipoxgenase pathway of metabolism. The detailed and important information gained by the two labs elucidated the mode of action of factors crucially important to the function of the bovine CL. The data indicate that follicular granulosa cells make a major contribution to numbers of large luteal cells, OT and basal P4 production, as well as the content of cytochrome P450 scc. Granulosa-derived large luteal cells have distinct features: when luteinized, the cell no longer possesses LH receptors, its cAMP response is diminished yet P4 synthesis is sustained. This may imply that maintenance of P4 (even in the absence of a Luteotropic signal) during critical periods such as pregnancy recognition, is dependent on the proper luteinization and function of the large luteal cell.
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Gootwine, Elisha, David Thomas, Ruth Braw-Tal, Amir Bor, and P. J. Dziuk. Improvement of Prolificacy of Israeli and U.S. Sheep Breeds through Inclusion of the F Gene of the Booroola Merino-Stage II. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7604931.bard.
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The purposes of this project were: 1) to introduce the FecB gene to the Awassi and Assaf breeds in Israel and the Rambouillet breed in the U.S.A. aiming in the long run to establish Awassi, Assaf and Rambouillet nucclei breeding flocks homozygous for the F gene in which the contribution of the Booroola Merino genetic background will be less than 10%; (In the U.S., Booroola crosses with Suffolk and Targhee were also studied. 2) to evaluate the effect of the FecB gene and different proportions of Booroola Merino genetic background on lamb survival, growth, milk production and wool production in Booroola crosses with the native breeds; 3) to reveal the specific effect of the FecB gene on ovarian development, follicle stimulating hormone (FSH) and inhibin secretion in prepubertal ewe lambs and in adult ewes in order to define physiological criteria for distinguishing carriers of the FecB allele from non-carriers and 4) to identify genetic markers linked to the FecB gene to assist in selection of genotypes within the Booroola crosses. Introgression of the Booroola gene reached the stage of the third backcross in the Awassi, Assaf and the Rambouillet crosses. In all cases the Booroola crosses were superior in prolificacy. However, they were inferior in comparison to the local breeds in production due to Booroola Merino genes other than the FecB. It is expected that the beneficial economic contribution of the Booroola gene will increase along with the upgrading to the local breeds. FSH plasma levels and induced ovulation rate of 5 month old FecB carriers among the crossbreeds. The OarAE101 marker can assist in detecting FecB carriers among Booroola-Awassi crosses. However, this marker is informative only in some of the families.
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Wolfenson, David, William W. Thatcher, Rina Meidan, Charles R. Staples, and Israel Flamenbaum. Hormonal and Nutritional Stretegies to Optimize Reproductive Function and Improve Fertility of Dairy Cattle during Heat Stress in Summer. United States Department of Agriculture, 1994. http://dx.doi.org/10.32747/1994.7568773.bard.
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The BARD program includes two main parts. In the first, experiments were conducted to complete our understanding of the mechanisms responsible for the impairment of reproductive functions under heat stress. Experiments focused on follicular development and function, since results obtained in our previous BARD project indicate that the preovulatory follicle is susceptible to heat stress. The theca cells, sensitive to thermal stress, produced less androgen during the summer, as well as during the autumn. Similarly, luteinized theca cells obtained from cows in summer produced much less progesterone than in winter. Granulosa cells and luteinized granulosa cells were less susceptible to heat stress. A delayed effect of heat stress on follicular development, on suppression of dominance and on steroid production by theca and granulosa cells was noted. This may be related to the low fertility of cows during the cool months of autumn. In the second part, experiments were conducted aiming to improve fertility in summer. The timed AI program was developed using two injections of GnRH coupled with PGF2a. It was found effective in improving reproductive performance in lactating cows. Limitations induced by heat stress on estrus detection were eliminated with the timed AI management program. Replacing the second injection of GnRH with hCG instead of GnRH agonist increased plasma progesterone levels post ovulation but did not improve fertility. Use of the timed AI program in summer, shortened days open and increased the net revenue per cow, however, it did not protect the embryo fiom temperature-induced embryonic mortality. Incorporation of a GnRH-agonist implant into the timed AJ program was examined. The implant increased plasma progesterone and LH concentrations and altered follicular dynamics. The use of a GnRH-implant enhanced pregnancy rate in cows with low body conditions. In a timed embryo transfer experiment, the use of fresh or frozen in vitro produced embryos was compared in the summer to improve fertility. The use of flesh embryos (but not frozen ones) improved pregnancy rate, however, substantial embryonic death occurred between 21 and 45 days. The timed AI program, which is now being used commercially, shortened days open, and increased pregnancy rate during summer. Other approaches which were found to improve fertility in small-scale studies, need to be tested again in large-scale field trials.
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Tummaruk, Padet. Impact of PRRS virus infection in the replacement gilts on number and development of follicles in the ovarian tissues. Chulalongkorn University, 2015. https://doi.org/10.58837/chula.res.2015.81.
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Replacement gilts are a major source of introducing the porcine reproductive and respiratory syndrome (PRRS) virus into the swine breeding herd. The objective of the present study was to determine the prevalence of PRRS virus antigen by detection in the ovary of gilts culled due to reproductive disturbances. Ovarian tissues were collected from 100 Landrace x Yorkshire crossbred slaughtered gilts in Thailand. PRRS virus antigen in the ovarian tissues were detected by using immunohistochemistry. On average, the gilts were culled at 277 days of age at a body weight of 148 kg. Of these gilts, 75 had attained puberty and 25 had not attained puberty. PRRS virus antigens were detected in the macrophages within the ovary. The histological morphology of macrophages containing the PRRS virus in ovarian tissue was similar to that found in lung tissue. Of all the ovarian tissues (n = 100), the PRRS virus was detected in 70 (70.0%) ovaries. The detection frequency of the PRRS virus in the ovarian tissue of gilts did not differ significantly among the culling reasons (P = 0.496). The gilts that had exhibited standing oestrus had a lower PRRS virus detection than those that had never exhibited standing oestrus (62.8% versus 92.0%, respectively, P = 0.005). Gilts with a body weight of 151 – 160 kg had a higher frequency of PRRS virus detection (89.5%) than gilts with a body weight of ≤130 kg (52.9%, P = 0.025) and 131–140 kg (50.0%, P = 0.032). The ovulation rate in the ovary containing the PRRS virus tended to be lower than the ovary without the PRRS virus (14.8 and 16.7 CL, respectively, P = 0.196). These findings indicated that the natural exposure to PRRS virus in the replacement gilts caused an existence of the virus in the ovarian tissues and may subsequently influence the ovarian function.
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Britt, Jack, Miriam Rosenberg, Steven Washburn, and Moshe Kaim. Development and Evaluation of a Method of Hormonal Treatment to Increase Fertility in Dairy Cows. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7612833.bard.
Full textAbstract:
The objectives were: 1) to develop a practical method for improving conception rates of dairy cows by administering progesterone during the critical period of the luteal phase prior to first insemination, 2) to determine which cows respond best to such a progesterone treatment, and 3) to determine physiological changes that are associated with this treatment. Experiment 1, conducted in the US and Israel, tested three treatment protocols. Holstein cows: 1) served as controls, 2) received two injections of prostaglanding F2a (PGF) 14 days apart, or 3) received two PGF injections and were inserted with a progesterone releasing intravaginal device (PRID) for 6 days beginning 9 days after the first injection of PGF. Fertility was positively related to plasma progesterone concentations prior to the second PGF injection, but PRID treatment did not improve fertility in cows with low progesterone. Cows in synchronized estrus 2-8 days after the second injection of PGF had higher fertility and better reproductive performance than non-synchronized cows. Experiment 3, conducted in Israel, involved three studies that assessed effect of PRID treatment on: 1) progesterone concentration in ovarian tissue and uterine tissue and fluids, 2) changes in systemic LH and estradiol, and 3) development and function of dominant follicles. Treatment with PRID increased progesterone in uterine tissue and fluid exclusive of effects on systemic concentrations. Low progesterone resulted in persistent follicles that exceeded normal size and produced excessive estrogen. Experiment 4, conducted in the US, evaluated influence of endogenous progesterone on embryo development. Cows were given two injections of PGF 14 days apart and single embryos were recovered 7 days after estrus. Among cyclic cows, there was a linear relationship between progesterone concentration and percentage of cows from which an embryo was recovered. Overall these experiments show that systemic progesterone concentrations affect fertility in high-producing dairy cows through effects on follicular development and embryo survival
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Hansen, Peter J., Zvi Roth, and Jeremy J. Block. Improving oocyte competence in dairy cows exposed to heat stress. United States Department of Agriculture, 2014. http://dx.doi.org/10.32747/2014.7598163.bard.
Full textAbstract:
Original Objectives. The overall goal is to develop methods to increase pregnancy rate in lactating dairy cows exposed to heat stress through methods that minimize damage to the oocyte and embryo caused by heat stress. Objectives were as follows: (1) examine the protective effects of melatonin on developmental competence of oocytes exposed to elevated temperature in vitro; (2) test whether melatonin feeding can improve developmental competence of oocytes in vivo and, if so, whether effects are limited to the summer or also occur in the absence of heat stress; and (3) evaluate the effectiveness of improving fertility by facilitating follicular turnover in the summer and winter. Revised Objectives. (1) Examine protective effects of melatonin and follicular fluid on developmental competence of oocytes exposed to elevated temperature in vitro; (2) examine the protective effects of melatonin on developmental competence of embryos exposed to elevated temperature in vitro; (3) evaluate effectiveness of improving fertility by administering human chorionicgonadotropin (hCG) to increase circulating concentrations of progesterone and evaluate whether response to hCG depends upon genotype for four mutations reported to be related to cow fertility; and (4) identify genes with allelic variants that increase resistance of embryos to heat shock. Background. The overall hypothesis is that pregnancy success is reduced by heat stress because of damage to the oocyte and cleavage-stage embryo mediated by reactive oxygen species (ROS), and that fertility can be improved by provision of antioxidants or by removing follicles containing oocytes damaged by heat stress. During the study, additional evidence from the literature indicated the potential importance of treatment with chorionicgonadotropin to increase fertility of heat- stressed cows and results from other studies in our laboratories implicated genotype as an important determinant of cow fertility. Thus, the project was expanded to evaluate hCG treatment and to identify whether fertility response to hCG depended upon single nucleotide polymorphisms (SNP) in genes implicated as important for cow fertility. We also evaluated whether a SNP in a gene important for cellular resistance to heat stress (HSPA1L, a member of the heat shock protein 70 family) is important for embryonic resistance to elevated temperature. Major conclusions, solutions & achievements. Results confirmed that elevated temperature increases ROS production by the oocyte and embryo and that melatonin decreases ROS. Melatonin reduced, but did not completely block, damaging effects of heat shock on the oocyte and had no effect on development of the embryo. Melatonin was protective to the oocyte at 0.1-1 μM, a concentration too high to be achieved in cows. It was concluded that melatonin is unlikely to be a useful molecule for increasing fertility of heat-stressed cows. Treatment with hCG at day 5 after breeding increased first-service pregnancy rate for primiparous cows but not for multiparous cows. Thus, hCG could be useful for increasing fertility in first-parity cows. The effectiveness of hCG depended upon genotype for a SNP in COQ9, a gene encoding for a mitochondrial-function protein. This result points the way to future efforts to use genetic information to identify populations of cows for which hormone treatments will be effective or ineffective. The SNP in HSPA1L was related to embryonic survival after heat shock. Perhaps, genetic selection for mutations that increase cellular resistance to heat shock could be employed to reduce effects of heat stress on fertility. Implications, both scientific and agricultural. This project has resulted in abandonment of one possible approach to improve fertility of the heat-stressed cow (melatonin therapy) while also leading to a method for improving fertility of primiparous cows exposed to heat stress (hCG treatment) that can be implemented on farms today. Genetic studies have pointed the way to using genetic information to 1) tailor hormonal treatments to cow populations likely to respond favorably and 2) select animals whose embryos have superior resistance to elevated body temperatures.