Department of Biological Sciences, University of South Carolina, Columbia, 29205, USA.
Gene. 2011 Feb 1;472(1-2):1-6. doi: 10.1016/j.gene.2010.10.015. Epub 2010 Nov 6.
In Diptera (Insecta), alternatively spliced male-specific and female-specific products of the doublesex (dsx) gene play a key role in regulating development of the adult genital structures from the genital disc. Analysis of the pattern of nucleotide substitution of different domains of the dsx gene in 29 dipteran species showed that, over short evolutionary times, purifying selection predominated on the domain common to both sexes, the female-specific exons, and the and male-specific exon. However, over longer the evolutionary time frames represented by between-family comparisons, the male-specific exon accumulated nonsynonymous substitutions at a much more rapid rate than either the common domain or the female-specific exon. Overall, the accumulation of nonsynonymous substitutions in the male-specific exon occurred at a significantly greater than linear rate relative to the common domain, whereas the accumulation of nonsynonymous substitutions in the female-specific exon occurred at less than linear rate relative to the common domain. The evolution of the male-specific exon of dsx thus shows a pattern reminiscent of that seen in the "runaway" evolution of male secondary sexual characters at the morphological level, consistent with the hypothesis that female choice is an important factor in the morphological diversification of insect male genitalia.
在双翅目昆虫（节肢动物门）中，性别特异性的 doublesex（dsx）基因的可变剪接产物在调节从生殖器盘发育成成体生殖器结构方面起着关键作用。对 29 种双翅目物种的 dsx 基因不同结构域的核苷酸替代模式进行分析表明，在较短的进化时间内，性别共有域、雌性特异性外显子和雄性特异性外显子都受到纯化选择的主导。然而，在更长的进化时间框架内，通过种间比较来表示，雄性特异性外显子积累非同义突变的速度比性别共有域或雌性特异性外显子快得多。总的来说，雄性特异性外显子积累非同义突变的速度明显快于共有域，而雌性特异性外显子积累非同义突变的速度则慢于共有域。dsx 的雄性特异性外显子的进化模式与形态水平上雄性次要性征的“失控”进化相似，这与雌性选择是昆虫雄性生殖器形态多样化的一个重要因素的假设是一致的。
