Chang H Y, Wang D G, Ayala F J
Department of Ecology and Evolutionary Biology, University of California, Irvine 92717.
J Mol Evol. 1989 Apr;28(4):337-48. doi: 10.1007/BF02103430.
The Drosophila nasuta group consists of about 12 closely related species distributed throughout the Indo-Pacific region. They are of great interest because of their evolutionary idiosyncrasies including little morphological differentiation, the ability to intercross in the laboratory often producing fertile offspring, and substantial chromosomal evolution. Studies of metric traits, reproductive isolation, and chromosomal and enzyme polymorphisms have failed to resolve the phylogeny of the species. We report the results of a survey of the mitochondrial DNA (mtDNA) restriction patterns of the species. The phylogeny obtained is consistent with other available information and suggests that D. albomicans may represent the ancestral lineage of the group. The amount of polymorphism in local populations (pi = 1.0% per site) is within the typical range observed in other animals, including Drosophila. The degree of differentiation between species is, however, low: the origin of the group is tentatively dated about 6-8 million years ago. This study confirms the usefulness of mtDNA restriction patterns for ascertaining the phylogeny of closely related species.
纳苏果蝇组由约12个亲缘关系密切的物种组成，分布于整个印度-太平洋地区。它们因其进化特性而备受关注，这些特性包括形态分化极小、在实验室中经常能够杂交产生可育后代以及显著的染色体进化。对度量性状、生殖隔离以及染色体和酶多态性的研究未能解决这些物种的系统发育问题。我们报告了对该物种线粒体DNA（mtDNA）限制酶切图谱的调查结果。所得的系统发育与其他现有信息一致，并表明白腹黑果蝇可能代表该组的祖先谱系。当地种群的多态性水平（每一位点的π值 = 1.0%）在包括果蝇在内的其他动物所观察到的典型范围内。然而，物种之间的分化程度较低：该组的起源时间初步确定为约600 - 800万年前。这项研究证实了mtDNA限制酶切图谱在确定亲缘关系密切物种的系统发育方面的有用性。
