Exploring the Roles of Fecundity-related Long Non-coding RNAs and mRNAs in the Adrenal Gland of Small-tailed Han Sheep
Long non-coding RNAs (lncRNAs) can play important roles in uterine and ovarian functions. However, little researches have been done on the role of lncRNAs in the adrenal gland of sheep. Herein, RNA sequencing was used to compare and analyze gene expressions in adrenal tissue between follicular phase and luteal phase in FecB BB (MM) and FecB ++ (WW) sheep, respectively, and differentially expressed lncRNAs and genes associated with reproduction were identified. Results: In MM sheep, 38 lncRNAs
... sheep, 38 lncRNAs and 545 mRNAs were differentially expressed in the adrenal gland between the luteal and follicular phases; In WW sheep, 513 differentially expressed lncRNAs and 2481 mRNAs were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that differentially expressed lncRNAs and their target genes are mainly involved in the circadian rhythm, the mitogen activated protein kinase, thyroid, ovarian steroidogenesis and transforming growth factor beta signaling pathways. Differentially expressed lncRNAs can regulate reproduction by modulating genes involved in these signaling pathways and biological processes. Specifically, XLOC_254761, XLOC_357966, 105614839 and XLOC_212877 targeting CREB1, PER3, SMAD1 and TGFBR2, respectively, appear to play key regulatory roles. Conclusion: These results broaden our understanding of lncRNAs in adrenal gland of sheep and provide new insights into the molecular mechanisms underlying sheep reproduction. Background Small-tailed Han sheep are famous for their high fertility, precocious puberty, good fur quality and tall body shape in China  . The behavior of estrus and mate in Small-tailed Han sheep appear year-round. The lambing rate of primiparous ewes is about 200%, and in produced ewes is higher than 250%  . Fec BB mutations have huge economic benefits in production, which can significantly increase the number of ovulation and lambs in sheep. According to the previous research report of this team, all three genotypes of FecB (FecB BB , FecB B+ and FecB ++ ) are distributed in Small-tailed Han sheep, and there is a significant correlation between the three genotypes of FecB and the lamb size of ewes  . Therefore, Small-tailed Han sheep can be used as an ideal animal model to study the molecular mechanism of FecB gene regulation of reproductive traits. Abbreviations LncRNAs: long noncoding; MAPK: the mitogen-activated protein kinase cascade; HPA: the hypothalamic-pituitary-adrenal axis; HPG: the hypothalamic-pituitary-gonadal axis; CRH: corticotropin releasing hormone; ACTH: the release of adrenocorticotropic hormone; GnRH: gonadotropin releasing hormone; CREB1: Cyclic AMP response element binding protein 1; BRAF: serine/threonine kinase; mGCs: mouse granulocytes; NTRK2: neurotrophic receptor tyrosine kinase 2; LHCGR: luteinizing hormone receptor; FSH: follicle stimulating hormone; SMAD1: Mothers against decapentaplegic homolog 1; BMP15: bone morphogenetic protein 15; TGFBR1: TGF-1 receptor subtypes; TGFBR2: type 2 receptor subtypes; MAS: marker-assisted selection.