基于线粒体细胞色素氧化酶I（COI）序列的猪和兔四个疥螨分离株的系统发育关系分析

为了探讨兔疥螨分离株和猪疥螨分离株的分类地位, 采用PCR技术首次扩增了分离自中国猪和兔的4个疥螨分离株的线粒体细胞色素氧化酶I（COI）基因, 并与GenBank中注册的14个国外疥螨分离株的同源基因进行了比较。序列分析结果显示: 扩增的4个疥螨株COI基因长度均为1 427 bp, 序列间无插入、缺失, A+T含量（73%）明显高于G+C含量（27%）, 碱基组成存在明显偏移。猪和兔的4个疥螨分离株间的COI基因同源性较高（99.1%～100.0%）, 它们与澳大利亚人疥螨株、国外动物疥螨株的同源性范围为98.4%～99.6%。在构建的NJ树中, 分离自中国猪和兔的4个疥螨分离株同澳大利亚人疥螨分离株、国外动物疥螨分离株亲缘关系较近。根据疥螨COI基因同源性分析和系统树构建结果, 我们认为分离自中国猪和兔的4个疥螨分离株与澳大利亚人疥螨分离株以及国外的动物疥螨分离株均应属于同一个种。

Phylogenetic relationships among four Sarcoptes isolates from rabbits and swine in China based on the mitochondrial COI gene sequences

To clarify the taxonomic status of four Sarcoptes isolates from rabbits and swine in China, the cytochrome oxidase subunit I (COI) gene from these specimens was sequenced and compared with the homologous genes of other fourteen Sarcoptes isolates from other countries deposited in GenBank. The results of sequence analysis indicated that the lengths of COI genes in the four Sarcoptes isolates were all 1 427 bp. There was no insert or deletion. The base composition was obviously A+T biased, averaging 73%. Homology analysis indicated that the identity levels of nucleotide of COI genes among the four isolates from China ranged from 99.1% to 100.0%, while the homology of COI gene between the Sarcoptes isolated from China and the Sarcoptes isolates from human in Australia and those from other animals abroad ranged from 98.4% to 99.6%. The phylogenetic analysis showed that the relationships among Sarcoptes isolates from China and the Sarcoptes isolates from human in Australia and other animals abroad were close. Homology and phylogenetic analysis indicated that the Sarcoptes isolates from China and the Sarcoptes isolates from human in Australia and other animals abroad are conspecific.