Russo C A, Takezaki N, Nei M
Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park 16802, USA.
Mol Biol Evol. 1995 May;12(3):391-404. doi: 10.1093/oxfordjournals.molbev.a040214.
The phylogenetic relationships and divergence times of 39 drosophilid species were studied by using the coding region of the Adh gene. Four genera--Scaptodrosophila, Zaprionus, Drosophila, and Scaptomyza (from Hawaii)--and three Drosophila subgenera--Drosophila, Engiscaptomyza, and Sophophora--were included. After conducting statistical analyses of the nucleotide sequences of the Adh, Adhr (Adh-related gene), and nuclear rRNA genes and a 905-bp segment of mitochondrial DNA, we used Scaptodrosophila as the outgroup. The phylogenetic tree obtained showed that the first major division of drosophilid species occurs between subgenus Sophophora (genus Drosophila) and the group including subgenera Drosophila and Engiscaptomyza plus the genera Zaprionus and Scaptomyza. Subgenus Sophophora is then divided into D. willistoni and the clade of D. obscura and D. melanogaster species groups. In the other major drosophilid group, Zaprionus first separates from the other species, and then D. immigrans leaves the remaining group of species. This remaining group then splits into the D. repleta group and the Hawaiian drosophilid cluster (Hawaiian Drosophila, Engiscaptomyza, and Scaptomyza). Engiscaptomyza and Scaptomyza are tightly clustered. Each of the D. repleta, D. obscura, and D. melanogaster groups is monophyletic. The splitting of subgenera Drosophila and Sophophora apparently occurred about 40 Mya, whereas the D. repleta group and the Hawaiian drosophilid cluster separated about 32 Mya. By contrast, the splitting of Engiscaptomyza and Scaptomyza occurred only about 11 Mya, suggesting that Scaptomyza experienced a rapid morphological evolution. The D. obscura and D. melanogaster groups apparently diverged about 25 Mya. Many of the D. repleta group species studied here have two functional Adh genes (Adh-1 and Adh-2), and these duplicated genes can be explained by two duplication events.
利用乙醇脱氢酶（Adh）基因的编码区，研究了39种果蝇的系统发育关系和分歧时间。研究对象包括四个属——盗果蝇属（Scaptodrosophila）、扎氏果蝇属（Zaprionus）、果蝇属（Drosophila）以及（来自夏威夷的）管果蝇属（Scaptomyza），还有果蝇属的三个亚属——果蝇亚属（Drosophila）、隐管果蝇亚属（Engiscaptomyza）和Sophophora亚属。在对Adh、Adhr（Adh相关基因）、核rRNA基因以及线粒体DNA的一段905bp片段的核苷酸序列进行统计分析后，我们将盗果蝇属作为外类群。所得的系统发育树显示，果蝇物种的首次主要分化发生在Sophophora亚属（果蝇属）与包括果蝇亚属和隐管果蝇亚属以及扎氏果蝇属和管果蝇属的类群之间。随后，Sophophora亚属又分为威氏果蝇（D. willistoni）以及黑腹果蝇（D. melanogaster）物种组和果蝇（D. obscura）物种组的进化枝。在另一个主要的果蝇类群中，扎氏果蝇首先与其他物种分离，然后移民果蝇（D. immigrans）从其余物种组中分化出来。这个剩余的物种组随后又分为拟果蝇（D. repleta）物种组和夏威夷果蝇类群（夏威夷果蝇、隐管果蝇和管果蝇）。隐管果蝇和管果蝇紧密聚类。拟果蝇、果蝇和黑腹果蝇各物种组均为单系类群。果蝇亚属和Sophophora亚属的分化显然发生在约4000万年前，而拟果蝇物种组和夏威夷果蝇类群则在约3200万年前分离。相比之下，隐管果蝇和管果蝇的分化仅发生在约1100万年前，这表明管果蝇经历了快速的形态进化。果蝇和黑腹果蝇类群显然在约2500万年前发生了分化。这里研究的许多拟果蝇物种组的物种都有两个功能性的Adh基因（Adh-1和Adh-2），这些重复基因可以用两次重复事件来解释。
