Transcriptomic diversification of granulosa cells during follicular development between White Leghorn and Silky Fowl hens

Abstract

Egg production rate in chicken is related to the continuity of follicle development. In this study, we found that the numbers of white prehierarchical, dominant, and yellow preovulatory follicles in the high-yielding layer breed, White Leghorn (WL), were significantly higher than those in the low egg-yielding variety, Silky Fowl (SF). The proliferation and differentiation of granulosa cells (GCs) play an important role in follicle maturation. Histological observation revealed a large number of melanocytes in the outer granulosa layer of follicles in SF but not in WL. Finally, RNA-sequencing was used to analyze the gene expression profiles and pathways of the GC layer in the follicles in both WL and SF hens. Transcriptome analysis of prehierarchical GCs (phGCs) and preovulatory GCs (poGCs) between WL and SF showed that steroid hormone-, oxytocin synthesis-, tight junction-, and endocytosis-related genes were expressed at higher levels in WL phGCs than in SF phGCs, whereas the insulin signaling pathway- and vascular smooth muscle contraction-related genes were upregulated in SF phGCs. Fatty acid synthesis, calcium signaling, and Wnt signaling pathway-related genes were expressed at higher levels in WL poGCs than in SF poGCs; however, adrenergic signaling, cGMP-PKG, and melanogenesis-related genes were upregulated in SF poGCs. These results indicate that genes that promote GC proliferation and secretion of various sex hormones are more active in WL than in SF hens. The upregulated signaling pathways in SF help in providing energy to GCs and for angiogenesis and melanogenesis. In vitro experiments confirmed that both the proliferation of poGCs and synthesis of reproductive hormones were higher in WL than in SF hens.

In vitro culture and tissue-derived specific expression of melanocytes from ovary of adult Silky Fowl

“…The ovary is a sexual organ whose development and maturation are essential for ovulation ( Maddineni et al, 2008 ). Herein, we discovered that the highly expressed genes in postovulatory granulosa cells were consistent with those in SFOM ( Tai et al, 2022 ). This illustrates the tissue specificity of genes expressed by cells.…”

MFN2 regulates progesterone biosynthesis and proliferation of granulosa cells during follicle selection in hens

“…Proliferation and differentiation of granulosa cells are critical to the endocytosis of vitellogenin into the yolk of hierarchical follicles (Tai et al, 2022). Previous study elucidated that there is an obvious tendency in shifting expression profile from proliferation to differentiation of granulosa cells during the process of follicle selection in hens (Zhu, Fang, et al, 2019).…”

Transcriptome Analysis of Granulosa Cells Reveals Regulatory Mechanisms Related to Chicken Follicle Development

“…With the development of technology, many new methods have been improved upon and applied to the study of follicle development in poultry [ 16 ], especially RNA-seq technology [ 17 , 18 ]. Therefore, in this study, we collected the granulosa cells of pre-hierarchical follicles, and preovulatory follicles were taken as research objects.…”