Goose broodiness is involved in granulosa cell autophagy and homeostatic imbalance of follicular hormones

Abstract

Broodiness is observed in most domestic fowls and influences egg production. The goose is one of the most important waterfowls, having strong broody behavior. However, whether autophagy and follicular internal environment play a role in the broodiness behavior of goose is unknown. In this report, we analyzed the follicular internal environment and granulosa cell autophagy of goose follicles. The results show that the contents of hormones, including prolactin (PRL), progesterone (P4), and estradiol (E2), increased in broody goose follicles. Most importantly, the level of granulosa cell autophagy in broody goose follicles was elevated, detected by electron microscopy and western blotting. Also, the expressions of positive regulators of autophagy, including miR-7, miR-29, miR-100, miR-181, PRLR, LC3, p53,Beclin1, Atg9, and Atg12, were up-regulated and the expressions of negative regulators of autophagy, including miR-34b and miR-34c, were down-regulated in broody goose follicles. Our results suggest that goose broodiness is involved in increased granulosa cell autophagy and homeostasis imbalance of internal environment in the follicles. This work contributes to our knowledge of goose broodiness and may influence egg production.

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

“…Therefore, the transition from LWF to SYF might be the key point to control the egg production in the goose. Interestingly, we found that the autophagy of LWF and SYF appeared stronger in the broody stage than in the egg-laying stage, which is considered the main reason for broodiness in geese7. However, it is necessary to explain the relationships between broodiness and the establishment of follicle grades.…”

“…An elevated ambient temperature accelerated the broody process in turkeys by increasing the level of PRL10. Our previous study indicated that the broodiness was associated with autophagy7. During the broody stage, the level of autophagy, identified by scanning electron microscope and the ratio of LC3-II to LC3-I, was elevated, and the homeostasis of follicles was impaired in goose follicles7.…”

“…It is believed that the altered levels of reproductive endocrine hormones, including gonadotrophin (GnRH), prolactin (PRL), luteinizing hormone (LH), progesterone (P4), and estradiol (E2), are the major factors inducing the occurrence of broodiness789101112. The elevated levels of PRL, following the decrease of P4 and E2, induced the occurrence of broodiness89.…”

“…During the broody stage, the level of autophagy, identified by scanning electron microscope and the ratio of LC3-II to LC3-I, was elevated, and the homeostasis of follicles was impaired in goose follicles7. Also, many autophagy-related genes and miRNAs altered their expression in broody follicles tested by qPCR and miRNA transcriptome718. However, the mechanism of the occurrence of broodiness is not clear.…”

“…This mechanism of broodiness was considered to be controlled by a set of hormone-related genes of the ovarian tissues, including PRL and PRLR (prolactin receptor), and autophagy-related genes, including p53, Beclin1, Atg12, Atg9 , and Caspase3 in previous studies. However, based on our previous study, we speculated that their different expressions in follicles might be the cause inducing broodiness7. To deeply explore the mechanism of broodiness occurring in geese, we sampled the SWF, LWF, and SYF during egg-laying and broody stages, and analyzed the whole transcriptomic data.…”