ORIGIN OF PARTHENOGENETIC POPULATIONS AND THEIR PHYLOGENETIC RELATIONSHIPS IN APHIDS

蚜虫通常从春季到秋季进行单性生殖，有许多无性世代，秋季进行一次有性生殖。然而，完全孤雌生殖的生活史已经从这个典型的生活史中衍生了很多次。本研究通过对线粒体COI-COII区进行测序，确定了有性和无性种群之间的遗传分化程度以及无性种与无性种之间的系统发育关系。甘杉胶蛾Colopha kansugei是一种完全孤雌生殖的物种，广泛分布于日本西部、琉球群岛、中国南部、泰国北方和尼泊尔。寄主植物的生物地理学和化石记录表明，该物种自主要寄主植物灭绝以来持续了大约几百万年的孤雌生殖。线粒体COI-COII区的比较表明，该物种的种群之间的遗传分化水平较高。Fo ...更多信息 例如，立山居群和福冈居群之间在约1200个碱基对的DNA序列中存在8个位点的差异，并且这种差异对于种内分化来说是非常高的。因此，分子证据证实了C。kansugei长期以来一直进行孤雌生殖，而Colopha、Kaltenbachiella和Tetraneura的系统发育关系一直没有得到解决。基于线粒体COI-COII区域构建的分子系统学分析表明，Colopha是该属的第一个分支，Kaltenbachiella和Tetraneura形成姐妹分类群，这与寄主植物榆属的分布和古生物学证据相一致。Colopha与一个间断分布的榆属群有关，而Tetraneura和Kaltenbachiella与一个广泛而连续分布的榆属群有关。因此，分子信息有助于解决形态学信息无法解决的系统发育问题。少

Aphids typically reproduce parthenogenetically from spring to autumn with many asexual generations, and reproduce sexually once in autumn. However, wholly parthenogenetic life cycles have derived many times from this typical life cycle. This study determined the extent of genetic differentiation between sexual and asexual populations and phylogenetic relationships between sexual and asexual species in the genus Colopha with wholly asexual species, by sequencing the mitochondrial COI-COII region. Colopha kansugei is a wholly parthenogenetic species with a broad distribution in western Japan, the Ryukyu Islands, southern China, northern Thailand and Nepal. Biogeographical and fossil records of the host plants suggest that this species has continued parthenogenetic reproduction since the extinction of the primary host plants for about a few million years. Comparisons of mitochondrial COI-COII region indicated a high level of genetic differentiation between populations for this species. Fo … More r example, there was a difference of 8 sites in a DNA sequence of about 1200 base pairs between the Tateyama and Fukuoka populations, and this difference is exceptionally high for intraspesific differentiation. Therefore, molecular evidence confirms the hypothesis that C. kansugei has continued parthenogenetic reproduction for a long time.The phylogenetic relationships between Colopha, Kaltenbachiella and Tetraneura have been unsolved for a long time. Molecular phylogenies constructed based on the mitochondrial COI-COII region indicated that Colopha has first branched off the other taxa, and that Kaltenbachiella and Tetraneura form a sister taxon. This result is consistent well with the distributional and paleobiological evidence of the host plants, the genus Ulmus. Colopha is associated with a Ulmus group with disjunctive distribution, while Tetraneura and Kaltenbachiella are associated with a Ulmus group with a extensive and continuous distribution. Thus, molecular information was useful for solving the phylogenetic problem which morphological information was not able to deal with. Less