Bondinas George P, Loukas Michael G, Goulielmos George N, Sperlich Diether
Department of Genetics, Agricultural University of Athens, Greece.
Chromosoma. 2002 Nov;111(4):256-66. doi: 10.1007/s00412-002-0207-3. Epub 2002 Sep 6.
The actin genes of five nearctic species of the Drosophila obscura group were mapped by in situ hybridization, using the 5C actin gene of D. melanogaster as a probe. In all species but D. azteca eight actin loci were observed variously dispersed over all five (A- E) chromosomal elements. In D. azteca ten actin hybridization sites were found; four of which most probably originated by duplications or by transposition events. Although the five nearctic species differ from all other Drosophila species of the D. obscura group so far studied in the number of loci as well as in the chromosomal distribution and location of the actin loci, the uniformity of the main pattern with six actin loci throughout the genus Drosophila reinforces the hypothesis that the chromosomal elements have maintained their essential identities during the course of evolution. Our findings are in accordance with the conclusion that the nearctic D. obscura species have differentiated from a common ancestor of the palearctic species and that they belong to two distinct subgroups, the pseudoobscura and the affinis subgroups.
利用黑腹果蝇的5C肌动蛋白基因作为探针，通过原位杂交对果蝇暗果蝇组的五个新北区物种的肌动蛋白基因进行了定位。除阿兹特克果蝇外，在所有物种中均观察到八个肌动蛋白基因座，它们以不同方式分散在所有五个（A - E）染色体元件上。在阿兹特克果蝇中发现了十个肌动蛋白杂交位点；其中四个很可能是由重复或转座事件产生的。尽管这五个新北区物种在基因座数量以及肌动蛋白基因座的染色体分布和位置上与迄今为止研究的暗果蝇组的所有其他果蝇物种不同，但整个果蝇属中具有六个肌动蛋白基因座的主要模式的一致性强化了这样一种假设，即染色体元件在进化过程中保持了它们的基本特征。我们的研究结果与以下结论一致，即新北区的暗果蝇物种已从古北区物种的共同祖先分化而来，并且它们属于两个不同的亚组，即拟暗果蝇亚组和近缘亚组。
