scholarly journals Gonadotrophin-induced follicle development in red deer hinds during the breeding and non-breeding seasons

Reproduction ◽  
2001 ◽  
pp. 111-119 ◽  
Author(s):  
BJ McLeod ◽  
LM Meikle ◽  
MW Fisher ◽  
GH Shackell ◽  
DA Heath
Keyword(s):  
Health Status ◽  
Follicular Fluid ◽  
Red Deer ◽  
Single Injection ◽  
Antral Follicle ◽  
Chorionic Gonadotrophin ◽  
Follicle Development ◽  
Camp Production ◽  
Breeding Seasons

The effect of exogenous equine chorionic gonadotrophin (eCG) and endogenous (GnRH-treatment) gonadotrophins in promoting antral follicle development in red deer hinds was assessed during the breeding and non-breeding seasons. After progesterone pretreatment, hinds received no further treatment, a single injection of 300 iu equine chorionic gonadotrophin or infusion of GnRH (1.0 microg h(-1)) for up to 4 days. Ovaries were recovered (n = 5 per group) at the time of, or 36 h after, progesterone removal. All follicles > or = 2.0 mm in diameter were dissected out, their health status assessed and follicular fluid oestradiol content measured. Granulosa cells were counted and their capacity for oestradiol and cAMP production assessed in vitro. Oestrus, the preovulatory LH surge and ovulation rates were monitored in additional groups of hinds that had been treated identically (n = 5 per group). During the breeding season, all monitored animals ovulated, but five of 15 (one eCG, three GnRH, one progesterone alone) did not exhibit oestrus, and three (all eCG) had luteinized follicles. During seasonal anoestrus, four hinds (all eCG-treated) displayed oestrus, but only two ovulated. Two non-ovulating hinds (one eCG, one progesterone alone) had luteinized follicles. The total number of follicles, or of large (> or = 4 mm) follicles, did not differ significantly between seasons. There were proportionately more healthy follicles during seasonal anoestrus (P < 0.05). Treatment with GnRH, and to a lesser extent eCG, increased the number of oestrogenic follicles and their follicular fluid oestradiol content. In summary, exogenous and endogenous gonadotrophins affected antral follicle development similarly in both the breeding and non-breeding seasons, although the response was variable among animals and often associated with failure of oestrous expression, ovulation and with follicle luteinization.

scholarly journals Variation in antral follicle development during the follicular phase of the oestrous cycle in red deer (Cervus elaphus) hinds

Reproduction ◽  
2001 ◽  
pp. 697-705 ◽  
Author(s):  
BJ McLeod ◽  
LM Meikle ◽  
MW Fisher ◽  
TR Manley ◽  
DA Heath ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Follicular Fluid ◽  
Red Deer ◽  
Antral Follicle ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Aromatase Activity ◽  
Follicle Development ◽  
Follicle Diameter ◽  
Follicle Size

The aim of this study was to quantify antral follicle populations in cyclic red deer hinds and to monitor follicle development leading to ovulation. Oestrus was synchronized with exogenous progesterone and ovaries were recovered approximately 0, 12, 24 or 36 h (follicular phase) or 10 days (luteal phase) after progesterone withdrawal (n = 5 per group). All follicles > or = 2 mm in diameter were dissected out, health status was assessed, follicular fluid oestradiol content was measured, granulosa cells were harvested and their capacity for oestradiol and cAMP production was determined. The time of oestrus and the preovulatory LH surge were monitored in five control hinds. Deer ovaries contained 26.6 +/- 3.45 (mean +/- SEM) follicles > or = 2 mm in diameter (range 4-81), with at least one large antral follicle (diameter: 8.3 +/- 0.38 mm) per hind. There was a strong correlation between follicle size and granulosa cell population (r(2) = 0.676). Approximately half (50.7%) of the follicles were classified as healthy, with the percentage classified as atretic decreasing with increasing follicle size. Neither the total number of antral follicles nor their size distribution differed significantly among groups. There were significantly more (P < 0.05) healthy follicles at 24 h after progesterone withdrawal than at 0 h, when large oestrogenic follicles had fewer granulosa cells, lower follicular fluid oestradiol concentrations and lower aromatase activity (P < 0.05) than did those from other groups. In summary, antral follicle development in red deer is similar to that in other monovulatory ruminants, and at least one large follicle is present at all stages of the oestrous cycle.

scholarly journals Involvement of miRNAs in equine follicle development

Reproduction ◽  
2013 ◽  
Vol 146 (3) ◽  
pp. 273-282 ◽  
Author(s):  
S N Schauer ◽  
S D Sontakke ◽  
E D Watson ◽  
C L Esteves ◽  
F X Donadeu
Keyword(s):  
Cell Survival ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Ovarian Follicle ◽  
Follicle Development ◽  
Previous Evidence ◽  
Ovarian Follicle Development ◽  
Fluid Levels ◽  
Follicle Selection

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.

Effect of combined exogenous progesterone with luteotrophic support via equine chorionic gonadotrophin (eCG) on corpus luteum development, circulating progesterone concentrations and embryo development in cattle

2016 ◽  
Vol 28 (3) ◽  
pp. 269 ◽  
Author(s):  
L. O'Hara ◽  
N. Forde ◽  
P. Duffy ◽  
F. Randi ◽  
A. K. Kelly ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Embryo Quality ◽  
Single Injection ◽  
Chorionic Gonadotrophin ◽  
Serum Progesterone ◽  
Conceptus Development ◽  
Luteal Tissue ◽  
Exogenous Progesterone ◽  
Intravaginal Device

The aim was to examine the effect of a single intramuscular (i.m.) injection of equine chorionic gonadotrophin (eCG) on Day 3 after oestrus on corpus luteum (CL) development, circulating progesterone and conceptus development in cross-bred beef heifers. In Experiment 1, heifers received: (1) saline, or a single i.m. injection of eCG on Day 3 at (2) 250 IU (3) 500 IU (4) 750 IU or (5) 1000 IU. Administration of eCG resulted in increased luteal tissue area and progesterone and oestradiol concentrations compared with controls. In Experiment 2, heifers received (1) a progesterone-releasing intravaginal device (PRID Delta) from Day 3 to 5 or (2) a PRID Delta from Day 3 to 5 plus a single injection of 750 IU eCG on Day 3. In vitro-produced blastocysts (n = 10 per recipient) were transferred on Day 7 and heifers were slaughtered on Day 14 to assess conceptus development. Administration of eCG reduced the number of short cycles (6.3% vs 31.3%) and increased mean luteal tissue weight (P = 0.02). Insertion of a PRID Delta on Day 3 resulted in an elevation (P < 0.05) in serum progesterone until removal on Day 5. Administration of eCG at the time of PRID Delta insertion resulted in higher progesterone levels (P < 0.05) from Day 10 onwards. Conceptus dimensions were not affected. In conclusion, a single injection of eCG on Day 3 increased CL size and progesterone concentrations and, when given in conjunction with a progesterone-releasing device, appeared to reduce the number of short cycles, presumably due to its luteotrophic nature. The implications of the elevated oestradiol concentrations for embryo quality require further study.

scholarly journals Supplementation of c-type natriuretic peptide during the whole in vitro growth period benefits the development of murine secondary follicles

2020 ◽  
Author(s):  
Ang Li ◽  
Haixia Cao ◽  
Hongxia Li ◽  
Ruijiao Li ◽  
Huaixiu Wang ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Ovulation Induction ◽  
Germinal Vesicle ◽  
Antral Follicle ◽  
Control Group ◽  
Follicle Development ◽  
In Vitro Growth ◽  
Germinal Vesicle Breakdown ◽  
Preovulatory Follicles

Abstract Background Supplementation of c-type natriuretic peptide (CNP) in the culture medium shortly before in vitro maturation (IVM) has been reported to be effective in delaying meiotic resumption of murine oocyte. The present study investigated the effect of CNP supplementation during the whole period of in vitro growth (IVG) on the development of murine secondary ovarian follicles.Methods Late secondary ovarian follicles isolated from ovaries of Kunming mice were cultured in vitro with and without supplementation of CNP. In experiment 1, CNP was supplemented at the early stage and the follicle development was evaluated. In experiment 2 and 3, CNP was supplemented during the whole period of IVG. In experiment 2, follicle development and oocyte maturity were evaluated. In group 3, follicle development and rate of cleaved embryos after in vitro fertilization (IVF) was assessed.Results In control group in all 3 experiments, granulosa cells migrated from within follicle and adhered to the plate at different degrees. The follicles flattened and could not reach antral stage. About 39.8% (39/98) of the oocytes ovulated nakedly. As no antral follicle was obtained, IVF was not performed in control group in experiment 3. In experiment group in all 3 experiments, no migration of guanulosa cells was observed and the follicles grew three-dimensionally. Ovulation of naked oocyte decreased substantially. The rate of antral stage follicle were 45% (18/40) in experiment 1. This parameter was 75.9% (44/58) in experiment 2 and 3 combined. In experiment 2, in preovulatory follicles without ovulation induction, oocytes at germinal vesicle (GV) stage and germinal vesicle breakdown (GVBD) stage were 87.5% (14/16) and 12.5% (2/16), respectively. In preovulatory follicles with ovulation induction, no GV stage oocyte was retrieved, oocytes at GVBD and metaphase II (MII) stage were 50% (8/16), respectively. In experiment 3, among 18 follicles cultured, 12 cumulus-oocyte complexes (COC) ovulated automatically after ovulation induction. Eleven oocytes were fertilized and cleaved. Compared with control groups, the follicle development assessed by naked oocyte ovulation and follicle stage (preantral follicle and antral follicle) in experiment groups were significantly superior (p<0.0001). CNP effectively maintained oocytes’ meiotic arrest and enhanced fertilization competency.Conclusions The supplementation of CNP in culture system of murine late secondary follicle during the whole period of IVG could sustain the 3-dimensional structure of follicle, increase the antral formation rate. As a result, the oocyte’s competency to be fertilized was greatly improved.

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