初产母猪囊肿卵巢与发情卵巢转录组比较分析

Comparison and analysis of transcriptomes in cystic ovary and estrous ovary of primiparous sows

旨在系统比较初产母猪囊肿卵巢与发情卵巢的转录组水平表达的变化,探索母猪卵巢囊肿发生的遗传机制。以初产母猪的囊肿卵巢和发情卵巢为研究对像,用Illumina NovaSeq 6000测序系统进行转录组测序及生物信息学分析。结果表明,构建的6个cDNA文库中共得到46.68 Gb原始序列(Raw reads),质控处理后获得42.02 Gb纯净序列(Clean reads),各样品的Clean reads大小均达到6.74 Gb以上,与参考基因组(Sus scrofa 11.1)的比对率为97.33%~97.79%。与发情卵巢相比,从囊肿卵巢中共筛选到335个差异表达基因,其中上调表达的基因有121个,下调表达的基因有214个。另外,有4559个新转录本被发掘,与发情卵巢相比,有53个新转录本在相对表达量上存在显著差异,其中上调表达的有18个,下调表达的有35个。GO及KEGG通路分析结果显示,差异表达基因在多个与发生卵巢囊肿相关的通路中富集,如胆固醇代谢通路、Ⅰ型糖尿病通路、Ⅱ型糖尿病通路、糖尿病并发症中晚期糖基化终产物及其受体(AGE-RAGE)信号通路等。利用CytoHubba插件从差异表达基因的蛋白质-蛋白质互作(PPI)网络中筛选到10个核心节点基因,这些基因主要参与癌症通路、细胞凋亡通路、趋化因子活性通路、糖尿病并发症中AGE-RAGE信号通路,并在肿瘤发生、多囊卵巢综合征(PCOS)并发症、卵泡闭锁、卵巢老化等方面发挥作用。通路及核心基因的功能分析结果表明,糖尿病并发症中AGE-RAGE信号通路、CXCL12基因与卵巢囊肿高度相关,机体炎症和胰岛素功能异常可能是导致初产母猪卵巢囊肿病变的主要因素。研究结果可为揭示母猪卵巢囊肿的分子遗传机制提供重要理论依据,同时可为解析人类卵巢囊肿的遗传机制提供参考。

The aim of the study was to systematically compare transcriptome expression changes of cystic ovary and estrous ovary of primiparous sows,and to explore the genetic mechanism of sow ovarian cyst.In this study,cystic ovary and estrous ovary of primiparous sows were used as the research objects,and transcriptome sequencing and bioinformatics analysis were performed using Illumina NovaSeq 6000 platform.The results showed that a total of 46.68 Gb raw reads were obtained from the six sequencing libraries,and 42.02 Gb clean reads were obtained after quality control processing.The clean reads of each sample reached more than 6.74 Gb,and their comparison rate with the reference genome(Sus scrofa 11.1)was between 97.33%and 97.79%.Compared with estrous ovaries,there were 335 differentially expressed genes in cystic ovaries,including 121 up-regulated genes and 214 down-regulated genes.In addition,a total of 4559 new transcripts were explored in this study.Compared with estrous ovaries,53 new transcripts were significantly different in cystic ovaries,of which 18 were up-regulated and 35 were down-regulated.The final analysis of GO and KEGG pathway indicated that the differentially expressed genes were significantly enriched in some signaling pathways associated with ovarian cyst,such as cholesterol metabolism pathway,typeⅠdiabetes mellitus pathway,typeⅡdiabetes mellitus pathway,advanced glycation end products and their receptors(AGE-RAGE)signaling pathway in diabetic complications,etc.Ten hub genes were screened out from differentially expressed gene protein-protein interaction(PPI)network using CytoHubba plugin.These genes were mainly involved in cancer pathway,apoptosis pathway,chemokine activity pathway,and AGE-RAGE signaling pathway in diabetic complications,and played roles in tumorigenesis,polycystic ovary syndrome(PCOS)complications,follicular atresia,ovary aging,etc.Pathway and hub gene function analysis showed that AGE-RAGE signaling pathway in diabetic complications and CXCL12 gene were highly correlated with ovarian cysts,and body inflammation and abnormal insulin function were likely to be the main factors leading to ovarian cyst in primiparous sows.The results of this study provided an important theoretical basis for revealing the molecular genetic mechanism of sow ovarian cysts,and also provided a reference for the analysis of the genetic mechanism of human ovarian cysts.