豚鼠ESR2基因新的可变剪接体克隆及序列分析

Cloning and sequencing for new alternative splicing of ESR2 gene in Cavia porcellus

【目的】对豚鼠雌激素受体2(ESR2)基因进行克隆及序列分析,并预测分析其编码的蛋白序列,为提高豚鼠产仔性能及其育种打下基础。【方法】根据Gen Bank已公布的豚鼠ESR2基因序列(登录号XM_003472337)设计引物,以豚鼠卵巢组织总RNA为模板,RT-PCR扩增ESR2基因编码区序列(CDS),利用生物信息学分析其编码蛋白氨基酸的组成及理化性质、二级结构及与相关物种的同源性。【结果】克隆获得的豚鼠ESR2基因CDS长度为1650 bp,编码549个氨基酸,比参照序列(XM_003472337)少54个碱基,是ESR2基因新的可变剪接体,且第7外显子缺失;蛋白质二级结构预测结果表明,豚鼠ESR2成熟肽包含α螺旋、β折叠和无规卷曲3种二级结构元件,由于缺失18个氨基酸导致蛋白质结构发生变异;同源性分析结果显示,豚鼠与长尾龙猫、奥氏更格卢鼠、马、达马拉鼹鼠、裸鼢鼠、鼠狐猴、八齿鼠、猪和人的ESR2基因序列同源性分别为91%、87%、86%、91%、92%、86%、88%、92%和86%。【结论】克隆获得的豚鼠ESR2基因为新的可变剪接体,可作为研究豚鼠产仔性能及豚鼠育种重要的候选基因之一。

【Objective】ESR2 gene o f Cavia porcellus was cloned, its sequence was analyzed, and the coded protein structure was predicted and analyzed, in order to provide references for further research on farrowing performance and breeding of C. porcellus. 【Method】According to C. porcellus ESR2 gene sequence（accession no. XM_003472337） published in Gen Bank, a pair of primers was designed to amplify ESR2 gene coding sequence（CDS） of C. porcellus using RT-PCR. Then the obtained fragments were sequenced and indentified. The physicochemical properties and protein secondary structure of ESR2 was predicted and analyzed using bioinformatics software. 【Result】The CDS of cloned ESR2 gene in C. porcellus was 1650 bp in length, encoding 549 amino acids, and which differed with reference sequence（accession no. XM_003472337） owing to its lack of 54 bases. Therefore, it was speculated that the cloned sequence was a new alternative splicing of ESR2 gene, lacking the 7thexon. In addition, the prediction results of protein secondary structure showed that, C. porcellus ESR2 mature peptide contained three secondary structure elements, which were α helix, βfold, and random coil. ESR2 of C. porcellus shared amino acid sequence homologies of 91%, 87%, 86%, 91%, 92%,86%, 88%, 92%, 86% with those of Chinchilla lanigera, Dipodomys ordii, Equus caballus, Fukomys damarensis, Homo sapiens, Microcebus murinus, Octodon degus and Sus scrofa, respectively. 【Conclusion】The cloned ESR2 gene of C. porcellus is a new alternative splicing, and can be used as one of candidate genes for further research on farrowing performance and breeding of C. porcellus. C. porcellus has the closest genetic relationship with H. glaber and O. degus, and the farthest genetic relationship with Sus scrofa and Homo sapiens.