The characteristics of oviposition and hormonal and gene regulation of ovarian follicle development in Magang geese

Abstract

BackgroundEgg laying in Magang geese is characterized by extended interruption between clutches and lowing laying rate. Both the ovarian follicular development and ovulation characteristics, and the associated endocrine and molecular regulatory mechanisms involved are poorly understood, but could be important for guiding development of molecule aided selection of egg laying performances in geese. This study, therefore, recorded egg-laying characteristics of Magang geese, and the endocrine and molecular regulatory mechanisms of ovarian follicular development, maturation, and ovulation in Magang geese.MethodsOviposition, ovarian follicle development, and reproductive hormone and gene expression profiles were observed in a small flock of Magang geese.ResultsGreater than 73% of eggs were laid during the day. The average oviposition interval was 46.8 h (36–55 h). It took approximately 18 days for large white follicles to develop into mature F1 follicles; follicular growth was exponential. LHR expression levels increased from the small to the large mature follicles, but FSHR expression decreased in the granulosa and thecal layers. As the follicles matured, inhibin alpha and inhibin betaA expression increased in the granulosa layer. Activin IR, activin IIRA, activin IIRB, and beta-glycan expressions also increased as the follicles increased in size, but were more abundantly expressed in the thecal than in the granulosa layers. During the oviposition cycle, plasma concentrations of gonadal hormones decreased rapidly, whereas the level of PGFM peaked around ovulation. The profiles of activin, inhibin, follistatin, estradiol, and progesterone leading to ovulation were characterized.ConclusionsThe molecular and endocrine mechanisms that regulate follicular development in Magang geese are similar to those in chickens. Moreover, gonadotropin regulation and interaction between activin, inhibin, and follistatin secretion may govern 3-stage maturation in the final preovulatory follicles in Magang geese. The rapid rebound of post-ovulatory secretions of inhibin and follistatin may inhibit recruitment of new SYF recruitment once a sequence of eggs is started, and may limit the egg clutch size to no more than the number of LYFs present before the first sequence egg.

Transcriptome analysis of follicles reveals the importance of autophagy and hormones in regulating broodiness of Zhedong white goose

“…Also, the hormones, such as progesterone and estradiol function in regulating the development of follicles, ovulation, and sexual behaviors in birds28 and the altered levels of reproductive hormones are associated with broodiness7. In this study, we demonstrated that progesterone and estradiol increased and the expressions of hormone-related genes were altered in the broody follicles.…”

Insulin‐like growth factor 1 and life‐history evolution of passerine birds

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Evening Primrose Oil Ameliorates Hyperleptinemia and Reproductive Hormone Disturbances in Obese Female Rats: Impact on Estrus Cyclicity

“…Studies highlighted many hormones, growth factor and cytokines in the ovary playing crucial roles in the follicular development. The follicles grow and develop orderly under the control of endocrine hormone (69,70), growth factor precisely produced at different time points (71,72) and the cytokines associated with the development of follicles include TNF-α, IL1β, and interferon-γ (73)(74)(75). The impact of adiposity has been involved in troubles of female reproduction (1).…”