scholarly journals Studies of Follicular Vascularity Associated with Follicle Selection and Ovulation in Cattle

2007 ◽  
Vol 53 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Tomas J. ACOSTA
Keyword(s):  
Follicular Vascularity ◽  
Follicle Selection

Multi-scale modeling of the follicle selection process in the ovary

2005 ◽  
Vol 198 (1) ◽  
pp. 57-79 ◽  
Author(s):  
Nki Echenim ◽  
Danielle Monniaux ◽  
Michel Sorine ◽  
Frédérique Clément
Keyword(s):  
Selection Process ◽  
Multi Scale ◽  
Scale Modeling ◽  
Multi Scale Modeling ◽  
Follicle Selection

Selection of fewer dominant follicles in Trio carriers given GnRH antagonist and luteinizing hormone action replaced by nonpulsatile human chorionic gonadotropin†

2020 ◽  
Vol 103 (6) ◽  
pp. 1217-1228
Author(s):  
Victor E Gomez-León ◽  
João Paulo Andrade ◽  
Brian W Kirkpatrick ◽  
Sadrollah Molaei Moghbeli ◽  
Alvaro García-Guerra ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Gnrh Antagonist ◽  
Maximum Diameter ◽  
High Fecundity ◽  
Follicle Diameter ◽  
Follicle Selection ◽  
Selection Of

Abstract Studying selection of multiple dominant follicles (DFs) in monovulatory species can advance our understanding of mechanisms regulating selection of single or multiple DFs. Carriers of the bovine high fecundity Trio allele select multiple DFs, whereas half-sib noncarriers select a single DF. This study compared follicle selection during endogenous gonadotropin pulses versus during ablation of pulses with Acyline (GnRH antagonist) and luteinizing hormone (LH) action replaced with nonpulsatile human chorionic gonadotropin (hCG) treatment in Trio carriers (n = 28) versus noncarriers (n = 32). On Day 1.5 (Day 0 = ovulation), heifers were randomized: (1) Control, untreated; (2) Acyline, two i.m. doses (Days 1.5 and D3) of 3 μg/kg; (3) hCG, single i.m. dose of 50 IU hCG on Day 1.5 followed by daily doses of 100 IU; and (4) Acyline + hCG. Treatments with nonpulsatile hCG were designed to replace LH action in heifers treated with Acyline. Acyline treatment resulted in cessation of follicle growth on Day 3 with smaller (P < 0.0001) maximum follicle diameter in Trio carriers (6.6 ± 0.2 mm) than noncarriers (8.7 ± 0.4 mm). Replacement of LH action (hCG) reestablished follicle diameter deviation and maximum diameter of DFs in both genotypes (8.9 ± 0.3 mm and 13.1 ± 0.5 mm; P < 0.0001). Circulating follicle stimulating hormone (FSH) was greater in Acyline-treated than in controls. Finally, Acyline + hCG decreased (P < 0.0001) the number of DFs from 2.7 ± 0.2 to 1.3 ± 0.2 in Trio carriers, with most heifers having only one DF. This demonstrates the necessity for LH in acquisition of dominance in Trio carriers (~6.5 mm) and noncarriers (~8.5 mm) and provides evidence for a role of GnRH-induced FSH/LH pulses in selection of multiple DFs in Trio carriers and possibly other physiologic situations with increased ovulation rate.

scholarly journals Follicle Selection in Cattle: Role of Luteinizing Hormone1

2001 ◽  
Vol 64 (1) ◽  
pp. 197-205 ◽  
Author(s):  
O.J. Ginther ◽  
D.R. Bergfelt ◽  
M.A. Beg ◽  
K. Kot
Keyword(s):  
Follicle Selection

scholarly journals Transcriptome Analysis on Single Small Yellow Follicles Reveals That Wnt4 Is Involved in Chicken Follicle Selection

2017 ◽  
Vol 8 ◽  
Author(s):  
Yiya Wang ◽  
Qiuyue Chen ◽  
Zemin Liu ◽  
Xiaoli Guo ◽  
Yanzhi Du ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Follicle Selection

scholarly journals Anti-Müllerian hormone and polycystic ovary syndrome: a mountain too high?

Reproduction ◽  
2010 ◽  
Vol 139 (5) ◽  
pp. 825-833 ◽  
Author(s):  
Laura Pellatt ◽  
Suman Rice ◽  
Helen D Mason
Keyword(s):  
Polycystic Ovary Syndrome ◽  
Polycystic Ovary ◽  
Primordial Follicle ◽  
Serum Levels ◽  
Dominant Follicle ◽  
Ovary Syndrome ◽  
Inhibitory Role ◽  
Mullerian Ducts ◽  
Human Ovaries ◽  
Follicle Selection

Anti-Müllerian hormone (AMH) was initially thought to be produced solely by the foetal male during sexual differentiation to promote regression of the Müllerian ducts. Over the last decade, however, a new and interesting role has emerged for AMH in the ovary. In human ovaries, AMH is produced by granulosa cells from 36 weeks of gestation until menopause, with the highest expression being in small antral follicles. AMH production gradually declines as follicles grow; once follicles reach a size at which they are dominant, it has largely disappeared. Its removal from these larger follicles appears to be an important requirement for dominant follicle selection and progression to ovulation as AMH has an inhibitory role in the ovary, reducing both primordial follicle initiation and follicle sensitivity to FSH by inhibition of aromatase. It is for this reason that AMH is a focus of interest in polycystic ovary syndrome (PCOS). Serum levels are doubled, and granulosa cell production is greatly increased. Interestingly, there appear to be two groups of women with PCOS who can be distinguished by their AMH level: one group consists of those who have high levels which do not reduce with treatment and who respond less well to induction of ovulation, and a second group consists of those in whom the level is less elevated and reduces on treatment and who seem to respond rather better. Understanding the reason for the raised AMH in PCOS may give clues as to the mechanism of anovulation. To conclude, AMH appears to have a major inhibitory role during folliculogenesis, which may contribute to anovulation in PCOS.

129 Ovarian dynamics and gonadotropins during selection of the dominant follicle in postpartum lactating versus non-postpartum cycling mares

2020 ◽  
Vol 32 (2) ◽  
pp. 191
Author(s):  
M. Pastorello ◽  
M. O. Gastal ◽  
G. K. Piquini ◽  
D. B. Godoi ◽  
E. L. Gastal
Keyword(s):  
Growth Rate ◽  
Maximum Diameter ◽  
Sequential Data ◽  
Dominant Follicle ◽  
Follicle Diameter ◽  
The Mean ◽  
Low Levels ◽  
Follicle Selection ◽  
Ovarian Dynamics ◽  
Selection Of

The mare, compared to other livestock, has the shortest interval from partum to the first ovulation. In monovulatory species, the follicle deviation process in a wave is characterised by the continued growth of the dominant follicle (DF) and regression of the subordinate follicle. Although follicle diameter deviation, a key event of follicle selection, has been investigated during the oestrous and menstrual cycles, the occurrence of this phenomenon before the first postpartum ovulation seems to be unclear in all species. This study aimed to compare the follicular dynamics and gonadotropin profiles around the follicle diameter deviation day in postpartum lactating (PP Lactating; n=24) versus non-postpartum cycling (NPP Cycling; n=15) mares. On the day of parturition, every PP Lactating mare was paired with an NPP Cycling mare, and ovarian follicles (>4mm) were tracked daily by transrectal ultrasonography, and blood samples were collected. Data were analysed in the PP Lactating group according to the length of the partum-ovulation interval (POI; ≤22 and >22 days) and the postpartum interovulatory interval (PPIOI), and in the NPP Cycling group during two interovulatory intervals (1st and 2nd IOI). In addition, regardless of group, all four intervals were compared. We performed the FSH and LH assays using radioimmunoassay. Ovarian and hormonal parameters were analysed using ANOVA for sequential data. The day and diameter of the DF at the deviation (overall mean: 14.9±2.5 days; 21.7±0.4mm, respectively) were not different (P>0.05) between PP Lactating and NPP Cycling mares. However, when considering the length of POI, follicle deviation occurred 4.4±0.8 days earlier (P<0.001) in mares with POI ≤ 22 days than in mares with POI>22 days. No difference was found between PP Lactating and NPP Cycling mares within and between groups for the intervals from deviation to maximum diameter of the DF (10.4±0.4 days), for the intervals from deviation to ovulation (12.1±0.5 days), or for the growth rates of the DF from deviation to maximum diameter (2.6±0.1mm per day). The growth rate of the DF from deviation to ovulation (2.4±0.1mm per day) did not differ between PP Lactating and NNP Cycling mares; however, this growth rate was lower (P<0.03) in the POI, PPIOI, and 1st IOI compared with the 2nd IOI. The mean diameter of the DF around deviation (days −3 to 3; 22.5±0.3mm), and systemic FSH (days −4 to 4; 10.3±0.2ngmL−1) were not different between PP Lactating and NPP Cycling mares. Level of LH was lower (P<0.0001) around deviation (days −4 to 4) in the PP Lactating (0.7±0.0ngmL−1) versus the NPP Cycling mares (1.8±0.1ngmL−1). Results demonstrated that a partum effect occurs only on the day of deviation in mares during the foal heat (POI ≤ 22 days) and that low levels of LH during both intervals in PP Lactating mares were not detrimental to prevent ovulation.

scholarly journals Effects of RAC1 on Proliferation of Hen Ovarian Prehierarchical Follicle Granulosa Cells

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1589
Author(s):  
Thobela Louis Tyasi ◽  
Xue Sun ◽  
Xuesong Shan ◽  
Simushi Liswaniso ◽  
Ignatius Musenge Chimbaka ◽  
...  
Keyword(s):  
Cell Cycle Progression ◽  
Biological Effects ◽  
Expression Levels ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Mrna And Protein Expression ◽  
Chicken Ovary ◽  
New Evidence ◽  
Follicle Selection

RAC1 belongs to the small G protein Rho subfamily and is implicated in regulating gene expression, cell proliferation and differentiation in mammals and humans; nevertheless, the function of RAC1 in growth and development of hen ovarian follicles is still unclear. This study sought to understand the biological effects of RAC1 on granulosa cell (GC) proliferation and differentiation of hen ovarian prehierarchical follicles. Firstly, our results showed expression levels of RAC1 mRNA in the follicles with diameters of 7.0–8.0 mm, 6.0–6.9 mm and 1.0–3.9 mm were greater than other follicles (p < 0.05). The RAC1 protein was mainly expressed in oocyte and its around GCs and stromal tissues of the prehierarchical follicles by immunohistochemistry. Further investigation revealed the RAC1 gene remarkably enhanced the mRNA and protein expression levels of FSHR (a marker of follicle selection), CCND2 (a marker of cell-cycle progression and GC differentiation), PCNA (a marker of GC proliferation), StAR and CYP11A1 (markers of GC differentiation and steroidogenesis) (p < 0.05). Furthermore, our data demonstrated siRNA interference of RAC1 significantly reduced GC proliferation (p < 0.05), while RAC1 gene overexpression enhanced GC proliferation in vitro (p < 0.05). Collectively, this study provided new evidence that the biological effects of RAC1 on GC proliferation, differentiation and steroidogenesis of chicken ovary follicles.

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