基于转录组测序鉴定牛RFI表型差异相关circRNAs及其靶基因富集通路

Identification of circRNAs and their target gene enrichment pathways related to bovine RFI phenotype based on transcriptome sequencing

文章旨在探究circRNAs在牛剩余采食量(Residual feed intake,RFI)表型变异中潜在生物学作用。分别选取牛高、低RFI极端表型个体,分离下丘脑组织并提取总RNA,通过高通量测序筛选两组牛RFI相关差异表达circRNAs,并对差异circRNAs靶基因作功能富集分析。随机选取6个差异表达的circRNAs开展qRT-PCR验证。结果表明,circRNAs在外显子中占比最高,大部分circRNAs分布在100~500 nt。两组牛下丘脑组织中筛选出736个差异表达的circRNAs,其中低RFI组中上调表达421个,下调表达315个。GO及KEGG富集分析结果表明,靶基因主要富集于Ras GTPase结合、AMPK及mTOR等采食及能量代谢相关信号通路中。对差异circRNAs开展miRNA靶点预测,发现差异circRNAs与miR-103、miRNA-15a、miRNA-499和miR-33a/b等与食物摄入、能量代谢及脂肪沉积等相关miRNAs、mRNAs互作。qRT-PCR结果显示,随机选择的circRNAs组织表达模式与测序结果趋势一致。下丘脑组织差异表达circRNAs、其靶基因富集通路及circRNA-miRNA-mRNA互作可能在牛RFI表型差异调控中发挥重要生物学作用。

The purpose of this study was to explore the potential biological role of circRNAs in the phenotypic variation of Residual Feed Intake(RFI)in bovine.RFI related differentially expressed circRNAs were screened by high-throughput sequencing,and the target genes of differentially expressed circRNAs were analyzed.Six circRNAs were randomly selected for qRT-PCR verification.The results showed that sequenced circRNAs accounted for the highest proportion in exons,and most of the circRNAs were distributed between 100 and 500 nt.A total of 736 differentially expressed circRNAs were screened from the hypothalamus of two groups,of which 421 were up-regulated and 315 were down-regulated in the low RFI group.GO and KEGG enrichment analysis showed that the target genes were mainly enriched in Ras GTPase binding,AMPK,mTOR,feeding and energy metabolism signaling pathways.circRNAs predicted miRNA,mRNA targets and interacted with miR 103,miRNA 15a,miRNA 499 and miR 33a/b.The results of qRT-PCR showed that the tissue expression patterns of randomly selected circRNAs were consistent with the sequencing trends.Hypothalamic tissues differentially expressing circRNAs,their target gene enrichment pathways and circRNA-miRNA-mRNA interactions might play an important biological role in the regulation of phenotypic difference in bovine RFI.