Transcriptome comparative analysis of ovarian follicles reveals the key genes and signaling pathways implicated in hen egg production

Abstract

Background Ovarian follicle development plays an important role in determination of poultry egg production. The follicles at the various developmental stages possess their own distinct molecular genetic characteristics and have different biological roles in chicken ovary development and function. In the each stage, several genes of follicle-specific expression and biological pathways are involved in the vary-sized follicular development and physiological events. Identification of the pivotal genes and signaling pathways that control the follicular development is helpful for understanding their exact regulatory functions and molecular mechanisms underlying egg-laying traits of laying hens. Results The comparative mRNA transcriptomic analysis of ovarian follicles at three key developmental stages including slow growing white follicles (GWF), small yellow follicles (SYF) of recruitment into the hierarchy, and differentiated large yellow follicles (LYF), was accomplished in the layers with lower and higher egg production. Totally, 137, 447, and 229 of up-regulated differentially expressed genes (DEGs), and 99, 97, and 157 of down-regulated DEGs in the GWF, SYF and LYF follicles, including VIPR1, VIPR2, ADRB2, and HSD17B1 were identified, respectively. Moreover, NDUFAB1 and GABRA1 genes, two most promising candidates potentially associated with egg-laying performance were screened out from the 13 co-expressed DEGs in the GWF, SYF and LYF samples. We further investigated the biological effects of NDUFAB1 and GABRA1 on ovarian follicular development and found that NDUFAB1 promotes follicle development by stimulating granulosa cell (GC) proliferation and decreasing cell apoptosis, increases the expression of CCND1 and BCL-2 but attenuates the expression of caspase-3, and facilitates steroidogenesis by enhancing the expression of STAR and CYP11A1. In contrast, GABRA1 inhibits GC proliferation and stimulates cell apoptosis, decreases the expression of CCND1, BCL-2, STAR, and CYP11A1 but elevates the expression of caspase-3. Furthermore, the three crucial signaling pathways such as PPAR signaling pathway, cAMP signaling pathway and neuroactive ligand-receptor interaction were significantly enriched, which may play essential roles in ovarian follicle growth, differentiation, follicle selection, and maturation. Conclusions The current study provided new molecular data for insight into the regulatory mechanism underlying ovarian follicle development associated with egg production in chicken.

Transcriptomic analysis of the thyroid and ovarian stroma reveals key pathways and potential candidate genes associated with egg production in ducks

“…This is consistent with previously reported results ( Mishra et al, 2020 ). The genes enriched in the BP category of this study, including GABRA1, LPAR2 , and ATF3 , which have been reported to be possibly involved in regulating egg-laying performance( Bello et al, 2021 ; Chen et al, 2021 ), and GABRA1 can inhibit the proliferation of granulosa cells and stimulate apoptosis ( Sun et al, 2021 ).…”

DNA methylome and transcriptome identified Key genes and pathways involved in Speckled Eggshell formation in aged laying hens

“…Studies have shown that GABRA1 plays an important role in egg production. High expression levels of GABRA1 can inhibit the proliferation of granulosa cells, enhance cell apoptosis, and inhibit the synthesis and secretion of progesterone, resulting in reduced egg production [43][44][45]. The egg-laying rhythm of laying hens is a neuromodulatory process [46,47].…”

Transcriptomics and Metabolomics Analysis of the Ovaries of High and Low Egg Production Chickens

“…In a previous report, this gene was found to be associated with granulosa cell proliferation and apoptosis in the ovary [ 21 ]. However, Sun et al found that it may be at the GWF developmental stage and that high VIPR2 expression may be associated with brooding and lower egg-laying traits in hens [ 31 ]. In this study, it was found to have higher expression in high egg-laying ovaries and may have a positive effect on egg production.…”