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对离腹寡毛果实蝇性别决定基因transformer 2(tra-2)进行多角度的进化分析,为研究离腹寡毛果实蝇性别决定分子机制奠定基础。通过PCR结合RACE技术克隆瓜实蝇Bactrocera cucurbitae同源transformer 2基因的c DNA全长和内含子序列,并对该基因进行序列和进化分析。克隆得到瓜实蝇tra-2基因c DNA全长1467 bp,开放读码框753 bp,编码250个氨基酸残基,Gen Bank登录号为KR056217。瓜实蝇tra-2基因与其他6种离腹寡毛果实蝇的基因结构相似,均包含8个外显子和7个内含子。7种离腹寡毛果实蝇与实蝇科的地中海实蝇和按实蝇、蝇科的家蝇和丽蝇科的铜绿蝇为单一起源,而果蝇Tra-2表现出明显的分异。分子进化分析结果表明tra-2基因核苷酸变异主要来源于同义变异,接受净化选择压力。本研究明确了瓜实蝇tra-2的c DNA和基因组DNA结构特征,离腹寡毛果实蝇tra-2蛋白高度保守,主要接受净化选择压力。
The multi-angle evolutionary analysis of sex-determining transgene transformer 2 (tra-2) from Gracilaria septempunctata lays a foundation for the study on the molecular mechanism of sexuality of Gracilaria. The full length cDNA and intron sequences of homologous transformer 2 gene from Bactrocera cucurbitae were cloned by PCR and RACE. The gene was sequenced and analyzed. The full-length c cDNA of tra-2 gene was cloned and the open reading frame was 753 bp, which encoded 250 amino acid residues. The Gen Bank accession number was KR056217. The fruit fly tra-2 gene is similar in structure to the other 6 kinds of Gaeli fruit fly, and contains 8 exons and 7 introns. The fruit flies Tra-2 showed a significant difference in the single origin of the seven species of the Mediterranean fruit fly and the fruit fly, the Musca domestica and the Musca domestica in the fruit flies and the fruit flies. The results of molecular evolution analysis showed that the nucleotide variation of tra-2 gene mainly originated from synonymous variation and accepted the pressure of purification selection. In this study, the structural characteristics of cDNA and genomic DNA of tra-2 tractrix were identified. The tra-2 protein was highly conserved from the fruit fly tra-2, and was mainly subjected to the pressure of purification selection.