Popadić A, Anderson W W
Genetics Department, University of Georgia, Athens 30602-7223.
Proc Natl Acad Sci U S A. 1994 Jul 19;91(15):6819-23. doi: 10.1073/pnas.91.15.6819.
Although the chromosomal polymorphism for inversions in Drosophila pseudoobscura is one of the best studied systems in population genetics, the identity of the ancestral gene arrangement has remained unresolved for more than 50 years. There are more than 40 gene arrangements, and 4 of them (Standard, Hypothetical, Santa Cruz, and Tree Line) have been considered as candidates for the ancestral type. We propose a framework of competing hypotheses to distinguish among the alternatives. Two conclusions come from contrasting each hypothesis with the results from DNA sequencing and restriction mapping. First, not only Standard but also Hypothetical can be excluded as the ancestral gene arrangement. Second, although either Tree Line or Santa Cruz could be the ancestral type, the available data provide greater support for Santa Cruz.
尽管果蝇种倒位的染色体多态性是群体遗传学中研究得最为透彻的系统之一,但祖先基因排列的身份在50多年来一直没有得到解决。有40多种基因排列,其中4种(标准型、假设型、圣克鲁斯型和树系型)被认为是祖先类型的候选者。我们提出了一个相互竞争的假设框架,以区分这些备选方案。将每个假设与DNA测序和限制性图谱分析的结果进行对比,得出了两个结论。第一,不仅标准型,假设型也可以被排除作为祖先基因排列。第二,尽管树系型或圣克鲁斯型都可能是祖先类型,但现有数据为圣克鲁斯型提供了更多支持。