Tanuja M T, Ramachandra N B, Ranganath H A
Drosophila Stock Centre, Department of Studies in Zoology, University of Mysore, Manasagangotri, Mysore 570 006, India.
J Biosci. 2001 Sep;26(3):365-71. doi: 10.1007/BF02703746.
Interracial divergence is an important facet of speciation. The nasuta-albomicans complex of Drosophila with sixteen morphologically identical, karyotypically different but cross-fertile races is an excellent system to study a few dimensions of raciation. Drosophila nasuta nasuta, Drosophila nasuta albomicans, Cytorace 1, Cytorace 2, Cytorace 3 and Cytorace 4 of this subgroup have been subjected to male-, female- and multiple-choice mating experiments. Out of 8456 crosses conducted, 7185 had successful matings. The overall impression is that mating is far from random amongst these six closely related races of the nasuta-albomicans complex. The males of D. n. albomicans, Cytorace 1 and Cytorace 4 in male-choice, the females of Cytorace 1 and Cytorace 2 in female-choice, and the males and females of D. n. nasuta, D. n. albomicans, Cytorace 1 and Cytorace 4 against the males and females of Cytorace 2 in multiple-choice experiments, had significantly more homogamic matings than expected. Thus in this study of evolutionary experimentation on raciation under laboratory conditions, we have documented the initiation of preference for conspecific matings among closely related and independently evolving members of the nasuta-albomicans complex of Drosophila.
种间差异是物种形成的一个重要方面。果蝇的纳苏塔 - 阿尔博米坎斯复合体包含16个形态相同、核型不同但可杂交育的种族，是研究种族分化若干维度的绝佳系统。该亚组的纳苏塔果蝇、阿尔博米坎斯果蝇、细胞种族1、细胞种族2、细胞种族3和细胞种族4已进行了雄体选择、雌体选择和多选择交配实验。在进行的8456次杂交中，有7185次成功交配。总体印象是，在纳苏塔 - 阿尔博米坎斯复合体的这六个密切相关的种族之间，交配远非随机。在雄体选择实验中，阿尔博米坎斯果蝇、细胞种族1和细胞种族4的雄体；在雌体选择实验中，细胞种族1和细胞种族2的雌体；以及在多选择实验中，纳苏塔果蝇、阿尔博米坎斯果蝇、细胞种族1和细胞种族4的雄体和雌体与细胞种族2的雄体和雌体相比，同配交配显著多于预期。因此，在这项关于实验室条件下种族分化的进化实验研究中，我们记录了果蝇纳苏塔 - 阿尔博米坎斯复合体密切相关且独立进化的成员之间对同种交配偏好的起始。
