Brehm A, Krimbas C B, Sourdis J, Cariou M L
Department of Genetics, Agricultural University of Athens, Greece.
Genome. 1991 Jun;34(3):464-71. doi: 10.1139/g91-070.
The phylogenetic relationships among nine Drosophila species belonging to the obscura group were investigated by establishing the segments displaying banding homologies in their element B (equivalent to the U element of D. subobscura). The phylogenetic ordering of the species was accomplished using overlapping inversions. Two African species, D. kitumensis and D. microlabis, were investigated. These species are homosequential for their element B gene arrangement but differ from that of D. obscura by several rearrangements. Drosophila obscura seems to be most closely related to D. subsilvestris, from which the respective element B gene arrangements differ at least by six inversions. Three species, D. obscura, D. ambigua, and D. tristis, are closely related and form a cluster. Drosophila obscura displays an element B polymorphism for a pericentric inversion for which D. ambigua is fixed for one gene arrangement and D. tristis for the other. Both D. ambigua and D. tristis share a short distal inversion in the small arm of the chromosome, and differ in this respect from D. obscura. Drosophila madeirensis, D. guanche, and D. subobscura all share the same element B gene arrangement, which is acrocentric, but metacentric in all the other species mentioned. It was found that the gene arrangements of the species from the obscura cluster seem to occupy an intermediate position between those of the species of the D. subobscura cluster and those of the African one. The data reported generally are in good agreement with information provided in the literature.
通过确定在其B元素（相当于D. subobscura的U元素）中显示带型同源性的片段，研究了属于obscura组的9种果蝇之间的系统发育关系。使用重叠倒位完成了物种的系统发育排序。研究了两种非洲物种，D. kitumensis和D. microlabis。这些物种的B元素基因排列是同序列的，但与D. obscura的基因排列有几个重排差异。Drosophila obscura似乎与D. subsilvestris关系最为密切，它们各自的B元素基因排列至少有六个倒位差异。三种物种，D. obscura、D. ambigua和D. tristis关系密切，形成一个聚类。Drosophila obscura显示出一种着丝粒倒位的B元素多态性，其中D. ambigua固定为一种基因排列，D. tristis固定为另一种基因排列。D. ambigua和D. tristis在染色体短臂上都有一个短的远端倒位，在这方面与D. obscura不同。Drosophila madeirensis、D. guanche和D. subobscura都具有相同的B元素基因排列，即近端着丝粒，但在所有其他提到的物种中是中着丝粒。发现obscura聚类中的物种基因排列似乎占据了D. subobscura聚类中的物种和非洲聚类中的物种之间的中间位置。报告的数据总体上与文献中提供的信息一致。
