乌珠穆沁羊Myostatin基因的分子克隆及序列分析

Cloning and Sequencing of Myostatin Gene of Wuzhumuqin Sheep

采用纯种(多胸椎个体)乌珠穆沁羊,对该品种MSTN基因进行PCR分段扩增并克隆和测序。利用DNAMAN进行序列拼接,获得乌珠穆沁羊MSTN基因全长序列。该基因由3个外显子和2个内含子组成,外显子大小分别为373,374,381 bp,内含子大小分别为1 833,2 030 bp。CDS序列全长为1 128 bp,由375个氨基酸组成。MSTN基因编码蛋白的理论分子质量约为42.8 ku,PI值为7.01,亮氨酸的含量最高(9.9%),其次是赖氨酸(8.3%)。乌珠穆沁羊基因编码蛋白二级结构以随机卷曲结构为主,属于跨膜蛋白,跨膜区位于AA6-AA23之间,具有一个分泌信号肽结构。其氨基酸序列MQKLQICVYIYLFMLIVA具有TGF-β家族的特征。

The Wuzhumuqin sheep was employed in this study. We used the PCR technique to amplified the Myo- statin （MSTN） gene of Wuzhumuqin sheep, and then carried out cloning and sequencing. Full-length sequence of MSTN gene was obtained by sequence assembly using molecular biology software. The resuhs showed that Wuzhumuqin sheep MSTN gene had 3 exons and 2 introns. The size of exon Ⅰ , exonⅡ and exonⅢ were 373, 374, 381 bp especially. The size of intron Ⅰ and intron Ⅱ were 1833, 2 030 bp especially. The Full-length sequence of CDS was 1 128 bp and composed of 375 amino acids. Biological software analysis showed that the theoretical molecular weight of encoding protein of MSTN gene was 42.8 ku and PI was 7.01. Highest level of Leu （9.9%） was observed and followed by Lys （8.3%）. The secondary structure of Wuzhumuqin sheep MSTN protein was mainly random coil structure, which have characteristics of transmembrane protein. The transmembrane domain located between AA6-AA23 and showed secretion signal peptide structure. The amino acids sequence MQKLQICVYIYLFMLIVA, which may be characterized with TGF-β family,