Relationships in the Drosophila obscura species group, inferred from mitochondrial cytochrome oxidase II sequences.
Relationships in the Drosophila obscura species group, inferred from mitochondrial cytochrome oxidase II sequences.
复制标题
从线粒体细胞色素氧化酶 II 序列推断的暗果蝇物种组中的关系。
DOI：
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发表时间：
1993
影响因子：
10.7
通讯作者：
Hong Liu
中科院分区：
文献类型：
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作者：
A. Beckenbach;Yue Wei;Hong Liu
我们比较了 13 个暗色果蝇物种的线粒体细胞色素氧化酶 II 基因的序列。该调查包括 6 名 D. affinis 亚群成员、4 名 D. pseudoobscura 亚群成员和 3 名 D. obscura 亚群成员。在所有物种中，该基因长度为 688 个核苷酸，编码 229 个氨基酸加上终止密码子第一个位置 T 的蛋白质。这些序列显示了密切相关物种的典型高转换偏差，但对于序列差异 > 5% 的物种对，该偏差基本上被消除。使用邻接法和最大简约法推断物种组中的系统发育关系。这两个程序给出了可比较的结果，表明 D. affinis 和 D. pseudoobscura 亚群是单系群，它们之间的亲缘关系似乎比其中任何一个与 D. obscura 亚群的亲缘关系更近。我们使用颠换距离来估计分歧时间，基于对 D. obscura 物种组与 D. melanogaster 组分离时间的三种不同估计。如果该事件发生在 35 Mya，那么我们可以估计近极形态的起源于大约 22 Mya，D. affinis 和 D.pseudoobscura 亚群的分离大约在 17 Mya。
We compare the sequences for the mitochondrial cytochrome oxidase II gene of 13 species of the Drosophila obscura group. The survey includes six members of the D. affinis subgroup, four of the D. pseudoobscura subgroup, and three of the D. obscura subgroup. In all species, the gene is 688 nucleotides in length, encoding a protein of 229 amino acids plus the first position T of the stop codon. The sequences show the typical high-transition bias for closely related species, but that bias is essentially eliminated for species pairs of > 5% sequence divergence. The phylogenetic relationships in the species group are inferred using both neighbor-joining and maximum parsimony. The two procedures give comparable results, showing that the D. affinis and D. pseudoobscura subgroups are monophyletic groupings that appear to have closer affinities to one another than either has to the D. obscura subgroup. We use transversion distances to estimate times of divergence, on the basis of three different estimates of the time of separation of the D. obscura species group from the D. melanogaster group. If that event occurred 35 Mya, then we can estimate the origin of the nearctic forms at approximately 22 Mya and the separation of the D. affinis and D. pseudoobscura subgroups at approximately 17 Mya.