Banerjee Parul, Singh B N
Genetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
Genetica. 2015 Aug;143(4):459-71. doi: 10.1007/s10709-015-9845-2. Epub 2015 May 19.
The Drosophila bipectinata species complex comprises of four very closely related species namely D. bipectinata, D. parabipectinata, D. malerkotliana and D. pseudoananassae. It was found that irrespective of the evolutionary divergence among the species, FA which is reflective of the developmental precision remains nearly same in four species. During the present study, the level of FA in different morphological traits was studied in interspecific hybrids and compared with that of parental species with the view that it would throw light on the degree of divergence between the parental species. If they have not diverged much, the interspecific hybrids may have a similar FA level, incompatibilities between their genomes being negligible. On the other hand, if there is substantial divergence, the level of FA may be higher due to incompatibility between the genomes of the parental species. The morphological traits taken were sternopleural bristle number and wing length in both males and females and ovariole number and sex-comb tooth number in females and males respectively. However, except in a few cases, we could not detect any significant differences in the level of FA in hybrids as compared to pure species. On the other hand, a number of abnormalities like poor viability, dystrophied ovaries, asymmetrical eyes etc., could be detected in hybrids from crosses involving D. pseudoananassae as one of the parents. Therefore, we conclude that specific developmental pathways are more susceptible to developmental disturbances due to genomic incompatibilities than the large complex system bringing about developmental stability.
果蝇双栉角蝇物种复合体由四个亲缘关系非常密切的物种组成，即双栉角蝇、拟双栉角蝇、马勒科特利亚纳果蝇和拟暗果蝇。研究发现，尽管这些物种之间存在进化差异，但反映发育精度的波动不对称性在这四个物种中几乎相同。在本研究中，对种间杂交种不同形态特征的波动不对称性水平进行了研究，并与亲本物种的水平进行了比较，以期了解亲本物种之间的分化程度。如果它们的分化不大，种间杂交种可能具有相似的波动不对称性水平，其基因组之间的不相容性可以忽略不计。另一方面，如果存在实质性分化，由于亲本物种基因组之间的不相容性，波动不对称性水平可能会更高。所选取的形态特征分别为雄性和雌性的腹侧刚毛数和翅长，以及雌性和雄性的卵巢管数和性梳齿数。然而，除了少数情况外，与纯种相比，我们在杂交种的波动不对称性水平上未检测到任何显著差异。另一方面，在以拟暗果蝇作为亲本之一的杂交种中，可以检测到许多异常情况，如活力差、卵巢萎缩、眼睛不对称等。因此，我们得出结论，特定的发育途径比带来发育稳定性的大型复杂系统更容易受到基因组不相容性导致的发育干扰。
