Ovarian function in ewes during the transition from breeding season to anoestrus

1999 ◽  
Vol 57 (1-2) ◽  
pp. 51-66 ◽  
Author(s):  
Pawel M Bartlewski ◽  
Andrew P Beard ◽  
Norman C Rawlings
Keyword(s):  
Breeding Season ◽  
Ovarian Function

scholarly journals Fetal Programming: Prenatal Testosterone Treatment Leads to Follicular Persistence/Luteal Defects; Partial Restoration of Ovarian Function by Cyclic Progesterone Treatment

Endocrinology ◽  
2006 ◽  
Vol 147 (4) ◽  
pp. 1997-2007 ◽  
Author(s):  
Mohan Manikkam ◽  
Teresa L. Steckler ◽  
Kathleen B. Welch ◽  
E. Keith Inskeep ◽  
Vasantha Padmanabhan
Keyword(s):  
Breeding Season ◽  
Luteal Phase ◽  
Ovarian Function ◽  
Corpora Lutea ◽  
Polycystic Ovaries ◽  
Partial Restoration ◽  
Prenatal Testosterone ◽  
P Concentration ◽  
Ovarian Morphology ◽  
Follicular Dynamics

Prenatal testosterone (T) excess during midgestation leads to estrous cycle defects and polycystic ovaries in sheep. We hypothesized that follicular persistence causes polycystic ovaries and that cyclic progesterone (P) treatment would overcome follicular persistence and restore cyclicity. Twice-weekly blood samples for P measurements were taken from control (C; n = 16) and prenatally T-treated (T60; n = 14; 100 mg T, im, twice weekly from d 30–90 of gestation) Suffolk sheep starting before the onset of puberty and continuing through the second breeding season. A subset of C and T60 sheep were treated cyclically with a modified controlled internal drug-releasing device for 13–14 d every 17 d during the first anestrus (CP, 7; TP, 6). Transrectal ovarian ultrasonography was performed for 8 d in the first and 21 d in the second breeding season. Prenatal T excess reduced the number, but increased the duration of progestogenic cycles, reduced the proportion of ewes with normal cycles, increased the proportion of ewes with subluteal cycles, decreased the proportion of ewes with ovulatory cycles, induced the occurrence of persistent follicles, and reduced the number of corpora lutea in those that cycled. Cyclic P treatment in anestrus, which produced one third the P concentration seen during luteal phase of cycle, did not reduce the number of persistent follicles, but increased the number of progestogenic cycles while reducing their duration. These findings suggested that follicular persistence might contribute to the polycystic ovarian morphology. Cyclic P treatment was able to only partially restore follicular dynamics, but this may be related to the low replacement concentrations of P achieved.

Ovarian function in ewes at the onset of the breeding season

1999 ◽  
Vol 57 (1-2) ◽  
pp. 67-88 ◽  
Author(s):  
Pawel M Bartlewski ◽  
Andrew P Beard ◽  
Norman C Rawlings
Keyword(s):  
Breeding Season ◽  
Ovarian Function

scholarly journals Multi-omics analysis reveals that natural hibernation is crucial for oocyte maturation in the female Chinese alligator

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Jian-Qing Lin ◽  
Jun Yu ◽  
Hua Jiang ◽  
Yi Zhang ◽  
Qiu-Hong Wan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Breeding Season ◽  
Oocyte Maturation ◽  
Ovarian Function ◽  
Epigenetic Mechanism ◽  
Limiting Factor ◽  
Chinese Alligator ◽  
Omics Analysis ◽  
Negative Effect ◽  
Warm Room

Abstract Background Hibernation in an appropriate environment not only is important for the survival of hibernators in winter, but also is crucial for breeding in the following season for many hibernating species. However, the genetic and epigenetic mechanism underlying this process remain unclear. In the current study, we performed an integrative multi-omics analysis of gonads collected from Chinese alligators that overwintered in wild cave and artificial warmroom to explore transcriptomic and epigenomic alternations in these organs. Results The data revealed that in the breeding season, female alligators were more strongly affected in terms of gene expression than males by non-hibernation because of overwintering in a warm room, especially for genes related to oocyte maturation, and this effect commenced in winter with the downregulation of STAR, which is the rate limiting factor of steroid biosynthesis. Further, miRNAs were found to play essential roles in this negative effect of overwintering in the warm room on hibernation. The upregulated miRNAs likely were responsible for the suppression of oocyte maturation in the breeding season. Finally, DNA methylome changes, especially hypomethylation, were found to play an important role in the alterations in ovarian function-related gene expression induced by non-hibernation. Conclusions Our study revealed the crucial role of hibernation quality for oocyte maturation in the Chinese alligator and the underlying genetic and epigenetic mechanisms, and highlights the importance of habitat, and especially, the overwintering site, in the conservation of not only the Chinese alligator, but also other endangered hibernators.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

THE CONTROL OF OVARIAN FUNCTION

1971 ◽  
Vol 66 (1) ◽  
pp. 1-15 ◽  
Author(s):  
B. T. Donovan
Keyword(s):  
Ovarian Function

Foetal steroid binding protein in British and Japanese women

1987 ◽  
Vol 114 (4) ◽  
pp. 584-588 ◽  
Author(s):  
M. Jawed Iqbal ◽  
Alastair Forbes ◽  
Mark L. Wilkinson ◽  
John W. Moore ◽  
Roger Williams ◽  
...  
Keyword(s):  
Ovarian Function ◽  
Binding Protein ◽  
Premenopausal Women ◽  
Japanese Women ◽  
Sex Hormone Binding Globulin ◽  
Partial Purification ◽  
Enzyme Linked Immunosorbent Assay ◽  
Binding Characteristics ◽  
Steroid Binding ◽  
Steroid Binding Protein

Abstract. In order to examine the newly-discovered sex-steroid binding protein, foetal steroid binding protein (FSBP) in different populations, its binding characteristics and its level were studied by two-tier column ligand binding assay and enzyme-linked immunosorbent assay (ELISA) respectively. In 10 Japanese premenopausal women, analysis of 5α-dihydrotestosterone (DHT) binding in the Cibacron Blue 3GA-Sepharose 6B portion of the column showed a rising plateau pattern with a mean maximum binding of 31.1 ± 7.41%, whereas of 9 similar British women, 8 displayed unsaturable, non-cooperative binding of 11.6 ± 8.22% (P < 0.01). After partial purification of FSBP in these samples, the protein exhibited saturable binding kinetics, median binding 25 (interquartiles 23–34) and 19 (13–25) nmol DHT/l in Japanese and British women, respectively (P < 0.05). By analyzing FSBP by ELISA in 56 Japanese (45 premenopausal) and 59 British (25 premenopausal) women, higher levels were obtained in the whole Japanese group (P = 0.0016) and in the premenopausal Japanese women (P = 0.018) than in their British counterparts. In both nationalities, FSBP levels were higher in premenopausal women, and there was a significant negative correlation of FSBP with age in both populations, particularly in postmenopausal women. FSBP levels did not correlate with weight, parity, sex hormone binding globulin or albumin levels. The influence of FSBP on free steroid levels remains unclear, but some relationship with ovarian function seems a possibility.

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