摘要
用细胞色素氧化酶Ⅱ基因特异性引物,对人工选育后的F3代池蝶蚌的线粒体细胞色素氧化酶Ⅱ基因进行PCR扩增和双向测序,在10个个体中均得到序列一致的细胞色素氧化酶Ⅱ基因序列,长度为681bp;A、T、G、C含量分别为19.4%(132个)、30.4%(207个)、38.9%(265个)和11.3%(77个),A+T含量(58.3%)明显高于G+C(41.7%)含量,与其它淡水珠蚌科种类相同基因片段的碱基含量相似;密码子上4种碱基使用出现偏倚性,密码子第1位上碱基G使用率高达38.8%,碱基T为29.5%;密码子第2位上碱基T的使用率为38.8%,碱基C的使用率低至15.9%;密码子第3位上碱基T的使用率高达48.5%,而碱基C的使用率仅为4%;第3位碱基T的使用率比第二位高,这种递增现象也出现在高等无脊椎动物昆虫的COⅡ上。BLAST结果显示池蝶蚌COⅡ与三角帆蚌具有较高的同源性,相似性为95%,MP法构建的分子系统进化树表明这两种淡水珍珠育珠蚌的亲缘关系最近。
In this research,cytochrome c oxidase subunit Ⅱ gene was amplified by PCR and sequenced from both directions in Hyriopsis Schlegelii of F3 population.The results showed that there was no difference in sequences among the ten samples.The number of its whole gene sequence was 681 bp in length which had 19.4%（132）、30.4%（207）、38.9%（265） 、11.3%（77）of A,T,G,and C,respectively,A＋T（58.3%）G＋C（41.7%）,similar to the sequences in other freshwater mussels of Unionidae.The three codon positions show a great asymmetry in base frequencies.The first codon positions had high content of G（38.8%）,and 14.1% of them were T;At the second codon positions,there are have high content of T（38.8%）but low content of C（14.1%）;At the third codon position,T is present at high frequency（48.5%） while C has an extremely low abundance（4%）.As in insects,COⅡ of Hyriopsis Schlegelii show higher compositional bias at the third position followed by the second position.The COⅡ gene of the H.Schlegelii was proved to have good homology with H.cumingii recorded in the GenBank.The sequence similarity between them was 95%.The result of Phylogenetic tree which was constructed by Maximum—Parsimony method indicated that there was the closest relationship of COⅡ between H.Schlegelii and H.cumingii.
出处
《南昌大学学报（理科版）》
CAS
北大核心
2010年第2期185-188,共4页
Journal of Nanchang University(Natural Science)
基金
农业部948资助项目(2004.T9)
国家发改办资助项目([2005]1899)
关键词
池蝶蚌
线粒体
COⅡ基因
序列分析
Hyriopsis Schlegelii
mitochondrion
COⅡ gene
sequence analysis
