Phylogeny of the sex-determining gene Sex-lethal in insects
Phylogeny of the sex-determining gene Sex-lethal in insects
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DOI：
10.1139/g05-107
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发表时间：
2006-03-01
期刊：
影响因子：
3.1
通讯作者：
Sahara, Ken
中科院分区：
文献类型：
--
作者：
Traut, Walther;Mimi, Teruyuki;Sahara, Ken
性致死蛋白(SXL)属于RNA结合蛋白家族，参与调控Pre-mRNA剪接。在昆虫分支的进化过程中，SXL经历了明显的功能变化。该基因在果蝇的性别决定途径中发挥了关键作用，尽管它在非果蝇中并不是性别决定因素。我们通过检索已发表的文献，对cDNA进行测序，并利用公共EST和全基因组数据库中的同源性搜索，收集了从豌豆蚜虫(Acyrtho-siphom siphum)到黑腹果蝇等昆虫物种的SXL序列。SXL蛋白具有中等保守的N-末端和C-末端区域，以及保守的中心区域，包括2个RNA识别基序。我们的系统发育分析表明，果蝇性致死(SXL)基因的单一同源基因存在于疟疾蚊子冈比亚按蚊、蜜蜂蜜蜂、家蚕和红粉甲虫的基因组中。然而，黑腹按蚊、直立按蚊和拟黑腹按蚊的基因组包含两个与按蚊、蜜蜂、家蚕和小按蚊SXL同源的同源基因SXL和CG3056。因此，在Fly Clade中的复制生成了SXL和CG3056。我们的假设认为，其中一个基因SXL在果蝇中采用了性别决定的新功能，而另一个基因CG3056继续提供一些或所有尚不清楚的祖先功能。
The Sex-lethal (SXL) protein belongs to the family of RNA-binding proteins and is involved in the regulation of pre-mRNA splicing. SXL has undergone an obvious change of function during the evolution of the insect clade. The gene has acquired a pivotal role in the sex-determining pathway of Drosophila, although it does not act as a sex determiner in non-drosophilids. We collected SXL sequences of insect species ranging from the pea aphid (Acyrtho-siphom pistum) to Drosophila melanogaster by searching published articles, sequencing cDNAs, and exploiting homology searches in public EST and whole-genome databases. The SXL protein has moderately conserved N- and C-terminal regions and a well-conserved central region including 2 RNA recognition motifs. Our phylogenetic analysis shows that a single orthologue of the Drosophila Sex-lethal (Sxl) gene is present in the genomes of the malaria mosquito Anopheles gambiae, the honeybee Apis mellifera, the silkworm Bombyx inori, and the red flour beetle Tribolium castaneum. The D. melanogaster; D. erecta, and D. pseudoobscura genomes, however, contain 2 paralogous genes, Sxl and CG3056, which are orthologous to the Anopheles, Apis, Bombyx, and Tribolium Sxl. Hence, a duplication in the fly clade generated Sxl and CG3056. Our hypothesis maintains that one of the genes, Sxl, adopted the new function of sex determiner in Drosophila, whereas the other, CG3056, continued to serve some or all of the yet-unknown ancestral functions.