Abstract

How multiple ovulations happen in prolific goats is still unknown even though studies on ovarian physiology and folliculogenesis have made extensive progress. MicroRNAs (miRNAs) are a class of endogenous regulatory factors and regulate structural gene expression mainly at the post-transcriptional level. In this study, in the follicular phase, six large follicles were collected from prolific Dazu black goat and used to generate RNA libraries for RNA sequencing. Based on the litter size and average number of ovulatory follicles in Dazu black goats, the largest three follicles were sorted as ovulatory follicles, and the remaining as subordinate ones. In total, 418 known miRNAs and 110 novel miRNAs were found, and the expression of six randomly selected miRNAs was validated by quantitative PCR analysis. Nine miRNAs were differently expressed between the ovulatory and subordinate follicles (p < 0.01). Chi-miR-582-5p, novel-130, chi-miR-214-3p, and chi-miR-500-5p were upregulated in the ovulatory group, and chi-miR-383, chi-miR-130b-5p, chi-miR-92a-3p, chi-miR-125b-5p, and novel-9 were downregulated in the same group. Chi-miR-130b-5p and chi-miR-214-3p were predicted to target at LHR (XM_013967581.1), GDF9 (NM_001285708.1), BMP15 (NM_001285588.1), and CYP19A1 (XM_013967046.1). In conclusion, nine miRNAs were differently expressed between ovulatory and subordinate follicles, and chi-miR-130b-5p and chi-miR-214-3p were predicted to regulate the expression of genes involved in gonadotropin hormone signaling and oocyte-derived growth factors. Additional studies are needed to confirm these findings.

摘要

尽管对卵巢生理学和卵泡发生的研究取得了广泛进展，但多产山羊如何发生多次排卵仍然未知。MicroRNAs (miRNAs) 是一类内源性调控因子，主要在转录后水平调控结构基因的表达。在这项研究中，在卵泡期，从多产的大足黑山羊身上收集了六个大卵泡，用于生成 RNA 文库以进行 RNA 测序。根据大足黑山羊产仔数和平均排卵卵泡数，将最大的三个卵泡分类为排卵卵泡，其余为次级卵泡。总共发现了 418 种已知的 miRNA 和 110 种新的 miRNA，并通过定量 PCR 分析验证了随机选择的 6 种 miRNA 的表达。p  < 0.01）。Chi-miR-582-5p、novel-130、chi-miR-214-3p和chi-miR-500-5p在排卵组上调，chi-miR-383、chi-miR-130b-5p、chi-miR-130b-5p、 chi-miR-92a-3p、chi-miR-125b-5p 和 novel-9 在同一组中被下调。Chi-miR-130b-5p 和 chi-miR-214-3p 预计靶向LHR (XM_013967581.1)、GDF9 (NM_001285708.1)、BMP15 (NM_001285588.1) 和CYP19A1 (XM_013967046.1)。总之，9 种 miRNA 在排卵卵泡和次级卵泡之间表达不同，预计 chi-miR-130b-5p 和 chi-miR-214-3p 会调节促性腺激素信号转导和卵母细胞衍生生长因子相关基因的表达。需要更多的研究来证实这些发现。