【摘要】 旨在克隆山羊SAMD12基因，明确SAMD12分子特征及表达特征，探究SAMD12基因对山羊肌内脂肪细胞分化的影响.首先通过RT-PCR技术扩增获得山羊SAMD12基因序列，利用生物信息学分析软件及qPCR技术明确山羊SAMD12分子特征及其在山羊组织、肌内脂肪细胞分化过程中的表达模式.结果表明，扩增获得山羊SAMD12基因序列734 bp, CDS区486 bp,编码氨基酸161个.山羊SAMD12特征分析结果显示SAMD12蛋白带正电且属于碱性亲水不稳定蛋白，主要分布于细胞核(52.2%),含有SAM家族所特有的SAM功能结构域.SAMD12蛋白二级结构中大部分氨基酸以α-螺旋、无规卷曲的方式存在.同源性比对结果显示山羊SAMD12与绵羊SAMD12同源性高达90.7%,同源性最低的为马(23.4%).系统进化树结果显示：山羊与绵羊、家牛划分为一支，说明山羊SAMD12与这两种哺乳动物亲缘关系最近.组织表达特征分析显示：SAMD12在山羊多个组织中均有表达，在瘤胃中表达量最高，其次为肾，这两种组织中的表达量都显著高于其他组织(P<0.05).细胞时序表达特征谱分析显示：成脂诱导分化后山羊SAMD12基因整体表达水平呈上升趋势，在诱导分化96 h时表达量达到最高值，显著高于0 h(P<0.05).以上结果提示，SAMD12基因在山羊肌内脂肪细胞成脂过程中可能起重要作用.更多还原

【Abstract】 The purpose of this study was to clone goat SAMD12 gene, identify its molecular characteristics and expression characteristics, and explore the effect of SAMD12 gene on the differentiation of goat intramuscular adipocytes.The goat SAMD12 gene sequence was amplified by RT-PCR.The molecular characteristics of goat SAMD12 and its expression pattern in the differentiation process of goat tissues and intramuscular adipocytes were identified by bioinformatics analysis software and qPCR technology.The results showed that the goat SAMD12 gene sequence was 734 bp, the CDS region was 486 bp, encoding 161 amino acids.The characteristic analysis of goat SAMD12 showed that SAMD12 protein was positively charged and belonged to basic hydrophilic unstable protein, mainly distributed in the nucleus(52.2%) and contained SAM functional domain specific to SAM family.The prediction results of the secondary structure of SAMD12 protein showed that most amino acids existed in alpha helix and random coil.The results of homology comparison showed that goat SAMD12 had 90.7% homology with sheep SAMD12,and horse SAMD12(23.4%) had the lowest homology.The phylogenetic tree showed that goat, sheep and cattle were divided into one branch, indicating that goat SAMD12 had the closest genetic relationship with these two mammals.The analysis of tissue expression characteristics showed that SAMD12 was expressed in many tissues, with the highest expression in the rumen, followed by the kidney.The expression of SAMD12 in these two tissues was significantly higher than that in other tissues(P<0.05).Temporal expression spectrum analysis showed that the overall expression level of SAMD12 gene in cells after adipogenic differentiation showed an upward trend, and the expression reached the highest value at 96 h of differentiation induction, significantly higher than that at 0 h(P<0.05).The above results suggest that SAMD12 may play a role in promoting intramuscular adipogenesis in goats.更多还原