miR-18a-5p在鸡不同生长时期的表达及其生物信息学分析与靶基因预测

为探究miR-18a-5p在鸡不同生长时期组织表达变化规律及其生物信息学特点,本研究以苏禽3号鸡为试验动物,利用实时荧光定量PCR技术检测不同生长时期鸡miR-18a-5p的组织表达变化。通过文献和miRBase检索脊椎动物的miR-18a-5p序列,利用Ensembl数据库确定miR-18a-5p在基因组中的位置,根据成熟序列构建系统进化树;使用miRmap、microT、miRanda和TargetScan网站预测miR-18a-5p靶基因,并进行GO和KEGG分析。组织表达分析结果显示,miR-18a-5p序列在鸡心脏、脾脏、肾脏和下丘脑中的表达量显著高于除大脑以外的其他组织(P<0.05)。与3日龄雏鸡相比,90日龄鸡心脏、脾脏、肾脏、腿肌和下丘脑中miR-18a-5p的表达量均显著上升(P<0.05)。在50种脊椎动物中共发现52条miR-18a-5p序列,几乎所有物种都只有1条成熟序列;基因定位分析发现,鸡miR-18a-5p位于1号染色体上的基因间隔区。多序列比对分析表明,不同物种miR-18a-5p的成熟序列同源性较高,物种间较为保守。系统进化树分析发现,鸡miR-18a-5p与原鸽、斑胸草雀等其他鸟类聚为一类,这表明miR-18a-5p进化过程中是保守的。靶基因预测和功能分析发现,miR-18a-5p共有121个靶基因。GO分析结果显示,靶基因主要富集到蛋白质泛素化、细胞周期阻滞、白细胞介素-6产生的负调控等功能。KEGG 通路分析表明,靶基因主要富集到细胞周期及Wnt和FoxO信号通路等。多个与肌肉生长及细胞增殖等相关的基因富集到相关通路之上。综上,鸡miR-18a-5p是组织广泛表达的miRNA,其可能通过Wnt及FoxO信号通路调控肌肉生长及细胞增殖分化。本研究为miR-18a-5p功能及调控机制的深入研究提供参考依据。

Gene Expression of miR-18a-5p at Different Growth Stages and Its Bioinformatics Analysis and Target Gene Prediction in Chicken

The object of this study was to explore the bioinformatics characteristics of miR-18a-5p and its changes in tissue expression in different growth stages of chickens.In this study, Suqin No.3 was used as the experimental material to detect the tissue expression of miR-18a-5p in chicken at different growth stages by Real-time quantitative PCR.The miR-18a-5p sequence of vertebrates was retrieved by references and miRBase.The position of miR-18a-5p in the genome was determined using the Ensembl database.Phylogenetic tree was constructed based on the mature sequence.The target genes of miR-18a-5p were predicted using miRmap, microT, miRanda and TargetScan websites, and GO and KEGG analysis was carried out.The results of tissue expression analysis showed that the expression of miR-18a-5p sequence of chicken in heart, spleen, kidney and hypothalamus was significantly higher than that in other tissues except brain (P<0.05).Compared with 3-day-old chicks, the expression of miR-18a-5p in heart, spleen, kidney, leg muscle and hypothalamus increased significantly at 90-day-old chicks (P<0.05).A total of 52 miR-18a-5p sequences were found in 50 vertebrates, and almost all species had only one mature sequence.A total of 52 miR-18a-5p sequences were found in 50 vertebrates, and almost all species had only one mature sequence.Gene mapping analysis showed that chicken miR-18a-5p was located in the gene spacer on chromosome 1.The multiple sequence alignment analysis showed that the mature sequences of miR-18a-5p in different species had high homology and were more conservative among species.Phylogenetic tree analysis showed that chicken miR-18a-5p clustered with other birds such as pigeon and zebra finch, which showed that miR-18a-5p was conservative in the evolution process.Target genes prediction and functional analysis revealed that there were 121 target genes in miR-18a-5p.GO analysis showed that the target genes were mainly enriched in protein ubiquitination, cell cycle arrest, negative regulation of interleukin-6 production and so on.KEGG pathway analysis showed that the target genes were mainly enriched in cell cycle, Wnt and FoxO signaling pathways.Multiple genes were related to muscle growth and cell proliferation were enriched on the related pathways.In conclusion, chicken miR-18a-5p was a miRNA which was widely expressed in different tissues, which might regulate muscle growth and cell proliferation and differentiation through Wnt and FoxO signaling pathway.This study provided a reference for the in-depth research of miR-18a-5p functions and regulatory mechanisms.