应用线粒体Cytb基因序列探讨果蝇科部分属间的系统发育关系

通过PCR产物直接测序的方法获得了果蝇科(Drosophilidae)果蝇属(Genus Drosophila)包括条纹果蝇亚属(Subgenus Dorsilopha)、果蝇亚属(Subgenus Drosophila)和水果果蝇亚属(Subgenus Sophophora)]、条果蝇属(Genus Phorticella)、姬果蝇属(Genus Scaptomyza)和花果蝇属(Genus Scaptodrosophila)的5个种6个单雌系的线粒体Cytb基因的部分DNA序列，用最大似然法、邻接法和Bayesian法分别构建系统树．研究结果表明：在选取的所有属和亚属中，花果蝇属的分化是最早的，其次是条纹果蝇亚属；姬果蝇属与果蝇亚属是近源的，条果蝇属同姬果蝇属和果蝇亚属形成的并系群是近源的；水果果蝇亚属早于果蝇亚属分化，水果果蝇亚属形成的支系是果蝇亚属和其它属(花果蝇属和姬果蝇属)形成的支系的姐妹分类单位．结果还表明线粒体Cytb基因可以作为有效的分子标记探讨高阶元的果蝇系统发育关系．

Phylogenetic relationships among several genera in Drosophilidae deduced from mitochondrial cytochrome b gene partial sequence

By directly sequencing method of the PCR products the partial nucleotide sequences of mitochondrial cytb gene for five species or six isofemale lines belonged to Genus Drosophila (It included Subgenus Dorsilopha,Subgenus Drosophila and Subgenus Sophophora), Genus Phorticella, Genus Scaptomyza and Genus Scaptodrosophila in Drosophilidae were acquired.Reconstructed phylogenetic trees using maximum likelihood, neighbor joining and Bayesian methods.The research indicated that:in all choosen genera and subgenera,Genus Scaptodrosophila diverged at first and the second was Subgenus Dorsilopha; Genus Scaptomyza and Subgenus Drosophila had close relations and formed a paraphyletic group ,Genus Phorticella and that group were paraphyletic; Subgenus Sophophora diverged before Subgenus Drosophila,and the clade constituted by the representative species of Subgenus Sophophora was the sister group to the clade formed by Subgenus Drosophila and other genera (Genus Phorticella and Genus Scaptomyza).Also indicated that mitochondrial cytochrome b gene can be applied to the research work of the phylogenetic relationships at high level in Drosophilidae as an effective molecular marker.