中文摘要：

已知mi R-21在多种生物学过程中发挥重要的调控作用,然而有关鸡mi R-21功能的研究尚未见报道。为了解鸡mi R-21的潜在生物学功能,采用q RT-PCR检测了固始鸡5个发育阶段、15种组织中mi R-21的表达情况。同时,利用Pictar和Target Scan算法预测了mi R-21的靶基因并对预测的靶基因进行了Gene Ontology分析和通路分析。结果显示,mi R-21的表达具有明显的时序特征,除14胚龄鸡的小脑和腺胃外,胚胎期各组织中mi R-21的表达水平均显著低于出壳后对应组织的表达水平;出壳后鸡的下丘脑、大脑、小脑、小肠、肝脏、胸肌和肾脏等组织中mi R-21的表达水平随发育进程均显著上调。生物信息学分析显示,预测的mi R-21的靶基因在基因表达调控、大分子代谢调控、转录调控、细胞代谢调控、细胞衰老和增殖、呼吸系统发育、骨骼发育、心脏发育和神经系统发育等广泛的生物学过程中显著富集。总之,鸡mi R-21为广泛性时序表达mi RNA,可能参与鸡出壳后诸多器官发育相关的生物学过程的调控。

英文摘要：

mi R-21 has been known to play an important role in many biological processes. However,the studies about mi R-21 function in chicken have not yet been reported. To comprehensively understand the potential biological function of mi R-21 in chicken,the expression of mi R-21 was detected in 15 different tissues of Gu-shi chicken at five developmental stages by q RT-PCR. The target genes for mi R-21 were predicted using Pictar and Target Scan,then subjected to Gene Ontology and pathway analysis. The results showed that the expression of mi R-21 has a striking temporal characteristics,the expression levels of mi R-21 in various tissues of the embryonic stages were significantly lower than those of hatched chicks except the cerebellum and glandular stomach at 14 days embryonic age. The expression levels of mi R-21 in hypothalamus, cerebrum, cerebellum, small intestine, liver, chest muscle and kidney were significantly upregulated with the development process in hatched chick tissues. The bioinformatics analysis showed that the predicted target genes of mi R-21 were significantly enriched in the biological processes of gene expression regulation,macromolecules metabolic regulation,transcriptional regulation,cell metabolic regulation, cell aging and proliferation, respiratory system development, skeletal development,heart development and nervous system development. In a word, chicken mi R-21 is ubiquitously expressed in all tissues examined and has temporal characteristic,may play an important role in the biological processes that related to many organ development in hatched chicks.