【摘要】 为明确绵羊IGF-Ⅰ基因变异剪接体的生物学特性及其在生长发育过程中的功能,本研究成功获得了IGF-Ⅰ基因Ⅱ类的2种变异剪接体(Ea和Eb型),利用生物信息学方法预测分析2种变异剪接体的结构特性,并探讨其在不同组织中的表达规律。结果表明:Ea和Eb型由同一基因通过选择性剪切形成,均是绵羊中新发现的类型,预测其分别编码138 aa和172 aa,2种变异剪接体的信号肽剪切位点、进化同源性、亚细胞定位、蛋白质空间结构预测结果类似,但二者包含不同的共价修饰位点。组织表达分析表明,2种变异剪接体在肝组织中表达量均最高,其次为脂肪、胃、睾丸、肌肉和皮肤组织,心、脾、肺、肾、肠、膀胱组织的表达水平较低;在胃中,羔羊期2种变异剪接体表达水平均极显著高于成羊期(P<0.01),在睾丸中,羔羊期IGF-Ⅰ基因Ⅱ类Ea型表达水平显著高于成羊期(P<0.05)。总体上来看,在各种组织中IGF-Ⅰ基因Ⅱ类Ea型的表达水平高于Eb型,为优势转录本类型。更多还原

【Abstract】 To identify their biological characteristics and functions in the process of growth and development of sheep IGF-Ⅰ splice variants, we successfully cloned the class Ⅱ IGF-Ⅰ gene splice variants(Ea and Eb), and utilized bioinformatics prediction webs to analysis the transcripts structure and detect their expression in different tissues. The results showed that sheep class Ⅱ-Ea and class Ⅱ-Eb IGF-Ⅰ gene, conceptually coding proteins of 138 aa and 172 aa, are newly cloned and from the same gene together with the class I-Ea in sheep. Bioinformatics analysis revealed that these two splice variants had same potential signal peptide cleavage sites, evolutionary homology, subcellular localization and protein spatial structure. But, they contained different numbers of covalent modification sites. Tissue expression analysis showed that all the two splice variants had the highest in the liver, followed by adipose, stomach, testis, muscle and skin, while in spleen, lung, kidney, intestine and bladder were low. In stomach, the expression level of two splice variants in lambs was higher than that of adult sheep(P<0.01); In testis, the expression level of class Ⅱ-Ea IGF-Ⅰ in lambs was higher than that of adult sheep(P<0.05). In general, the expression level of class Ⅱ-Ea IGF-Ⅰ gene in various tissues was higher than that of Eb type, which is the dominant transcriptional type.更多还原