Transformer gene regulates feminization under two complementary sex determination loci in the ant, Vollenhovia emeryi
Transformer gene regulates feminization under two complementary sex determination loci in the ant, Vollenhovia emeryi
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DOI：
10.1016/j.ibmb.2023.103938
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发表时间：
2023-04-07
影响因子：
3.8
通讯作者：
Miyakawa，Hitoshi
中科院分区：
文献类型：
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作者：
Miyakawa，Misato Okamoto;Miyakawa，Hitoshi
有性繁殖的有机体已经进化出组织良好的机制来决定性别。一些膜翅目动物(如蚂蚁、蜜蜂和黄蜂)有一个互补的性别决定系统，其中一个CSD基因座的杂合子诱导雌性发育，而该基因座的半合子或纯合子诱导雄性发育。这种系统会产生很高的近亲交配成本，因为在该基因座纯合子的个体会变成不育的二倍体雄性。另一方面，一些膜翅目昆虫已经进化出一个多基因座、互补的性别决定系统，在这个系统中，至少一个CSD基因座的杂合性诱导雌性发育。该系统有效地降低了二倍体雄性不育的比例；然而，这些基于CSD的多个
初级信号如何通过分子级联来调节下游基因仍不清楚。为了弄清这一问题，我们使用回交方法研究了具有两个CSD基因座的蚂蚁Vollenhovia meryi的分子级联。在这里，我们通过基因破坏表明，转换(Tra)是适当的女性化所必需的。变性和双性杂交的表达分析表明，至少在两个CSD基因座中的一个座位上的杂合性足以促进雌性性别决定。过表达分析表明，雌型Tra蛋白通过正调控反馈环促进trapre-mRNA剪接为雌型异构体。我们的数据还表明，Tra1影响dsx的剪接。我们得出结论：双基因座性别决定系统Inv.Emeryi是基于tra-dsx剪接级联进化而来的，这在其他昆虫物种中保存得很好。最后，我们提出了一个级联模型，以达到在多个主要信号下的性别的二元决定。
Organisms that reproduce sexually have evolved well-organized mechanisms to determine two sexes. Some hymenopterans (such as ants, bees, and wasps) have a complementary sex-determination system in which heterozygosity at one CSD locus induces female development, whereas hemi- or homozygosity at the locus induces male development. This system can generate a high cost of inbreeding, as individuals that are homozygous at the locus become sterile, diploid males. On the other hand, some hymenopterans have evolved a multi-locus, complementary, sex-determination system in which heterozygosity in at least one CSD locus induces female development. This system effectively reduces the proportion of sterile diploid males; however, how these multiple
primary signals based on CSD pass through a molecular cascade to regulate downstream genes has remained unclear. To clarify this matter, we used a backcross to investigate the molecular cascade in the ant,Vollenhovia emeryi, with two CSD loci. Here we show by gene disruption thattransformer(tra) is necessary for proper feminization. Expression analysis oftraanddoublesex(dsx) showed that heterozygosity in at least one of the two CSD loci is sufficient to promote female sex determination. Analysis of overexpression suggested that female-type Tra protein promotes splicing oftrapre-mRNA to female isoform by a positive-regulatory-feedback loop. Our data also showed thattraaffects splicing ofdsx. We conclude that two-loci sex determination system inV. emeryievolved based ontra-dsxsplicing cascade that is well conserved in other insect species. Finally, we suggest a cascade model to arrive at a binary determination of sex under multiple primary signals.