内蒙古绒山羊CRABP I基因的克隆及表达

【目的】克隆内蒙古绒山羊视黄酸结合蛋白Ⅰ（cellular retinoic acid binding proteinⅠ，CRABPⅠ）基因的cDNA，进行蛋白结构的预测和表达分析，为绒山羊毛和绒形成的分子机理奠定基础。【方法】利用RT-PCR方法克隆内蒙古绒山羊CRABPⅠ基因序列，利用生物信息学方法预测其蛋白结构，采用实时荧光定量PCR探讨该基因在绒山羊4个胎儿日龄皮肤中的表达。【结果】内蒙古绒山羊CRABP I基因cDNA长679 bp（JN936490），其开放阅读框为414 bp，氨基酸序列与其它物种相比具有较高的序列相似性。CRABP Ⅰ蛋白无明显的信号肽和跨膜区域，不存在N糖基化位点和O糖基化位点；蛋白二级结构主要由α 螺旋、β折叠和少量的转角及无规则卷曲构成。胎儿皮肤中CRABPⅠ基因在 90 d 的表达量明显高于100、120和130 d（P<0.05）。【结论】绒山羊的CRABPⅠ基因cDNA中的开放阅读框（open reading frame，ORF）在不同物种间较为保守，但种属特异性集中表现在第33和123氨基酸残基处，该基因在胎儿期的90 d表达量最大。

Cloning and Expression of Cellular Retinoic Acid Binding Protein Ⅰ Gene in Inner Mongolian Cashmere Goats

【Objective】The cDNA sequence of cellular retinoic acid binding protein Ⅰ(CRABP)Ⅰ gene was cloned in Inner Mongolian cashmere goats,and the protein structure gene and expression were also analyzed.All these would establish a foundation for molecular mechanism of follicle and cashmere formation.【Method】The cDNA sequence of CRABP I gene was cloned by RT-PCR in Inner Mongolian cashmere goats.The protein structure was predicted through bioinformatics approach,the mRNA expression of the gene at four embryo ages in skin of cashmere goat were detected through real time PCR.【Result】The length cDNA is 679 bp(JN936490),its open reading frame(ORF) is 414 bp,which shares high similarity with other species.CRABPⅠ protein has no obvious signal peptide,transmembrane segments,N-glycosylation sites and O-glycosylation sites.The secondary structure of CRABPⅠ protein consisted of mainly β sheets,α helixes and loops,also few turn and coil.CRABPⅠ gene in cashmere goats was highly expressed on 90 d compared with on 100 d,120 d and 130 d(P<0.05).【Conclusion】The open reading frame(ORF) of CRABPⅠ gene is conserved among different species,but it has characteristics at 33 and 123 amino sites in cashmere goats.The level of mRNA expression was the highest on 90 d at four embryo stages,the polymorphism of this gene in different breeds and its regulation mechanism to sebaceous gland of hair follicle needs to be studied further.