基因也有“性别歧视”

　　

生物通报道，你知道吗，基因也分派系，有偏帮男性的基因，也有偏帮女性的基因，也就是说，对男性有利的基因对女性则不利，反之亦然。据科学家介绍，这种遗传冲突（genetic conflict）有利于种族的遗传变异，这一研究成果公布在最近的《PLoS Biology》上。

 

来自瑞典的科学家以果蝇为研究模型，对基因在不同性别有机体中的表达形式和优势表达模式进行了充分的研究。

 

无论是哪种动物，只要不是雌雄同体，雌性和雄性看上去都是有很大的差别的，极易区分。在遗传学上，这种现象被认为是，有助于进化，有助于获得有利的遗传突变。从行为模式上就能看出它们的差异。

 

拿果蝇来说，雌性果蝇往往擅长于寻找有利于产卵的地点，而雄性则更擅长于交配和授精行为。这些不同造成了不同性别间的“利益冲突”，这些特征的产生由一系列的基因群来控制。

 

应用行为学研究和基因组研究技术，科学家们找到了一些影响性别冲突的基因。Paolo Innocenti和Ted Morrow表示，我们发现，对雄性有利的基因往往对雌性有害，反之亦然。

 

这些研究结果表明，基因组上存在有影响性别冲突的基因，这些基因多集中在决定性别的X染色体上，这些结果预示，不存在一种基因型是同时有利于2种性别的。

（生物通 小茜）

生物通推荐原文摘要

The Sexually Antagonistic Genes of Drosophila melanogaster

Paolo Innocenti*, Edward H. Morrow

Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden

【Abstract】

When selective pressures differ between males and females, the genes experiencing these conflicting evolutionary forces are said to be sexually antagonistic. Although the phenotypic effect of these genes has been documented in both wild and laboratory populations, their identity, number, and location remains unknown. Here, by combining data on sex-specific fitness and genome-wide transcript abundance in a quantitative genetic framework, we identified a group of candidate genes experiencing sexually antagonistic selection in the adult, which correspond to 8% of Drosophila melanogaster genes. As predicted, the X chromosome is enriched for these genes, but surprisingly they represent only a small proportion of the total number of sex-biased transcripts, indicating that the latter is a poor predictor of sexual antagonism. Furthermore, the majority of genes whose expression profiles showed a significant relationship with either male or female adult fitness are also sexually antagonistic. These results provide a first insight into the genetic basis of intralocus sexual conflict and indicate that genetic variation for fitness is dominated and maintained by sexual antagonism, potentially neutralizing any indirect genetic benefits of sexual selection.