Bao Riyue, Friedrich Markus
Department of Biological Sciences, Wayne State University, Detroit, MI, USA.
Mol Biol Evol. 2009 Jun;26(6):1273-87. doi: 10.1093/molbev/msp039. Epub 2009 Feb 27.
Using genomic information from mosquito, red flour beetle, honeybee, mouse, and sea anemone, we have studied the molecular evolution of 91 Drosophila genes involved in eye primordium determination, retinal differentiation, and phototransduction. Our results show that the majority of these gene sequences predate the diversification of endopterygote insects. However, all three functional groups contain a conspicuous fraction of evolutionarily younger genes, which originated by tandem duplication in the lineage leading to Drosophila, whereas gene duplications are rare in other insect lineages. We conclude that the retention of duplicated genes spiked during the early diversification of the higher Diptera possibly due to an extended period of exceptional population size reduction. Genetic data suggest that gene duplication played an important role in the evolution of visual performance in the fast flying higher Diptera by spatial or intracellular subfunctionalization. Developmental gene duplications, by contrast, predominantly retained overlapping expression patterns and preserved partial to complete redundancy consistent with a role in boosting developmental robustness.
利用来自蚊子、赤拟谷盗、蜜蜂、小鼠和海葵的基因组信息，我们研究了91个参与果蝇眼原基确定、视网膜分化和光转导的基因的分子进化。我们的结果表明，这些基因序列中的大多数早于内翅类昆虫的分化。然而，所有这三个功能组都包含相当一部分进化上较年轻的基因，这些基因是在导致果蝇的谱系中通过串联重复产生的，而基因重复在其他昆虫谱系中很少见。我们得出结论，在高等双翅目早期分化过程中，重复基因的保留可能由于种群规模异常减少的延长时期而激增。遗传数据表明，基因重复通过空间或细胞内亚功能化在快速飞行的高等双翅目的视觉性能进化中发挥了重要作用。相比之下，发育基因重复主要保留了重叠的表达模式，并保留了部分至完全冗余，这与增强发育稳健性的作用一致。
