Table 2_Lnc MSTRG 4701.7 targets miR-1786/RORa to competitively regulate proliferation and apoptosis in chicken follicular granulosa cells.doc

BackgroundFollicular development in chickens is a highly coordinated and complex process. While the hypothalamic–pituitary-gonadal axis plays a central regulatory role in this process, the role of long noncoding RNAs (LncRNAs) remains unclear. Here, we aimed to identify key differentially expressed LncRNAs and explore their regulatory roles in follicular development, particularly focusing on the MSTRG.4701.7-miR-1786-RORa axis, to provide insights for improving fertility in low-fertility chicken varieties.
MethodsIntact follicular tissues were collected from Jilin Black chickens (low-fertility group) and Lohmann Brown Laying hens (high-fertility group) at each stage of ovarian development for transcriptome sequencing to identify key differentially expressed LncRNAs for follow-up analyses. Bioinformatics analysis was also performed to determine the role of the MSTRG.4701.7-miR-1786-RORa regulatory axis, and to clarify whether that MSTRG 4701.7 targets miR-1786/RORa to competitively regulate the proliferation and differentiation of chicken follicular granulosa cells (GCs). We also knocked down and overexpressed key genes, MSTRG.4701.7 and miR-1786 and thereafter, determined changes in the mRNA and protein expression levels of axial terminal mRNA-RORa.
ResultsMSTRG.4701.7 promotes the apoptosis of chicken follicular GCs, while miR-1786 reverses this phenomenon. RORa was also identified as a functional target of miR-1786 in GCs, and as a competitive endogenous RNA, MSTRG.4701.7 regulated RORa expression by sponging miR-1786, thereby playing a regulatory role in GCs. Additionally, interfering with MSTRG.4701.7 expression significantly downregulated RORa mRNA and protein expression levels, while interfering with miR-1786 showed the opposite effect.
ConclusionMSTRG.4701.7 plays a critical role in follicular development in chickens by influencing GC proliferation, differentiation, and apoptosis. The resent results provide useful molecular evidence for elucidating the genetic mechanism underlying ovarian follicle development associated with egg production in chicken.

## 研究背景
鸡卵泡发育是一个高度协同且复杂的生物学过程。尽管下丘脑-垂体-性腺轴（hypothalamic–pituitary-gonadal axis）在该过程中发挥核心调控作用，但长链非编码RNA（long noncoding RNAs, LncRNAs）的调控功能仍未明确。本研究旨在筛选关键差异表达LncRNAs，探究其在鸡卵泡发育中的调控功能，重点关注MSTRG.4701.7-miR-1786-RORa调控轴，以期为提升低繁殖力鸡品种的繁殖性能提供理论依据。

## 研究方法
本研究分别于卵巢发育各阶段，从低繁殖力组吉林黑鸡与高繁殖力组罗曼褐壳蛋鸡中采集完整卵泡组织，进行转录组测序以筛选关键差异表达LncRNAs用于后续分析。同时通过生物信息学分析，解析MSTRG.4701.7-miR-1786-RORa调控轴的功能，并明确MSTRG.4701.7是否通过靶向miR-1786/RORa，竞争性调控鸡卵泡颗粒细胞（granulosa cells, GCs）的增殖与分化。此外，本研究对关键因子MSTRG.4701.7与miR-1786分别进行敲低与过表达处理，随后检测该调控轴末端靶基因RORa的mRNA与蛋白表达水平变化。

## 研究结果
MSTRG.4701.7可促进鸡卵泡颗粒细胞凋亡，而miR-1786可逆转这一效应。研究同时证实，RORa是miR-1786在颗粒细胞中的功能性靶基因；而MSTRG.4701.7作为竞争性内源RNA，通过海绵吸附miR-1786调控RORa的表达，进而在颗粒细胞中发挥调控功能。此外，抑制MSTRG.4701.7的表达可显著下调RORa的mRNA与蛋白表达水平，而抑制miR-1786则呈现相反的调控效果。

## 研究结论
MSTRG.4701.7通过影响鸡卵泡颗粒细胞的增殖、分化与凋亡，在鸡卵泡发育过程中发挥关键调控作用。本研究结果为阐明鸡产蛋相关卵巢卵泡发育的分子遗传机制提供了重要的实验依据。