Kwiatowski J, Skarecky D, Bailey K, Ayala F J
Department of Ecology and Evolutionary Biology, University of California, Irvine 92717.
J Mol Evol. 1994 May;38(5):443-54. doi: 10.1007/BF00178844.
The phylogeny and taxonomy of the drosophilids have been the subject of extensive investigations. Recently, Grimaldi (1990) has challenged some common conceptions, and several sets of molecular data have provided information not always compatible with other taxonomic knowledge or consistent with each other. We present the coding nucleotide sequence of the Cu,Zn superoxide dismutase gene (Sod) for 15 species, which include the medfly Ceratitis capitata (family Tephritidae), the genera Chymomyza and Zaprionus, and representatives of the subgenera Dorsilopha, Drosophila, Hirtodrosophila, Scaptodrosophila, and Sophophora. Phylogenetic analysis of the Sod sequences indicates that Scaptodrosophila and Chymomyza branched off the main lineage before the major Drosophila radiations. The presence of a second intron in Chymomyza and Scaptodrosophila (as well as in the medfly) confirms the early divergence of these two taxa. This second intron became deleted from the main lineage before the major Drosophila radiations. According to the Sod sequences, Sophophora (including the melanogaster, obscura, saltans, and willistoni species groups) is older than the subgenus Drosophila; a deep branch splits the willistoni and saltans groups from the melanogaster and obscura groups. The genus Zaprionus and the subgenera Dorsilopha and Hirtodrosophila appear as branches of a prolific "bush" that also embraces the numerous species of the subgenus Drosophila. The Sod results corroborate in many, but not all, respects Throckmorton's (King, R.C. (ed) Handbook of Genetics. Plenum Press, New York, pp. 421-469, 1975) phylogeny; are inconsistent in some important ways with Grimaldi's (Bull. Am. Museum Nat. Hist. 197: 1-139, 1990) cladistic analysis; and also are inconsistent with some inferences based on mitochondrial DNA data. The Sod results manifest how, in addition to the information derived from nucleotide sequences, structural features (i.e., the deletion of an intron) can help resolve phylogenetic issues.
果蝇的系统发育和分类一直是广泛研究的主题。最近，格里马尔迪（1990年）对一些常见概念提出了质疑，并且几组分子数据所提供的信息并不总是与其他分类学知识相符，也并非相互一致。我们给出了15个物种的铜锌超氧化物歧化酶基因（Sod）的编码核苷酸序列，这些物种包括地中海实蝇Ceratitis capitata（实蝇科）、Chymomyza属和Zaprionus属，以及Dorsilopha亚属、Drosophila属、Hirtodrosophila属、Scaptodrosophila属和Sophophora亚属的代表物种。对Sod序列的系统发育分析表明，Scaptodrosophila属和Chymomyza属在果蝇主要辐射分化之前就从主干谱系中分支出来了。Chymomyza属和Scaptodrosophila属（以及地中海实蝇）中存在第二个内含子，这证实了这两个分类单元的早期分化。这个第二个内含子在果蝇主要辐射分化之前就从主干谱系中缺失了。根据Sod序列，Sophophora亚属（包括黑腹果蝇、obscura、saltans和willistoni物种组）比Drosophila亚属更为古老；一个深度分支将willistoni和saltans物种组与黑腹果蝇和obscura物种组分开。Zaprionus属以及Dorsilopha亚属和Hirtodrosophila亚属表现为一个多产的“灌木丛”的分支，这个“灌木丛”还包括Drosophila亚属的众多物种。Sod的研究结果在许多方面（但并非所有方面）证实了思罗克莫顿（金，R.C.（编）《遗传学手册》。普伦出版社，纽约，第421 - 469页，1975年）的系统发育关系；在一些重要方面与格里马尔迪（《美国自然历史博物馆通报》197: 1 - 139，1990年）的分支系统分析不一致；并且也与一些基于线粒体DNA数据的推断不一致。Sod的研究结果表明，除了从核苷酸序列获得的信息之外，结构特征特征特征特征（即一个内含子的缺失）如何能够帮助解决系统发育问题。
