Genome assembly, sex-biased gene expression and dosage compensation in the damselfly Ischnura elegans
Genome assembly, sex-biased gene expression and dosage compensation in the damselfly Ischnura elegans
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DOI：
10.1016/j.ygeno.2021.04.003
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发表时间：
2021-04-22
期刊：
影响因子：
4.4
通讯作者：
Hansson, Bengt
中科院分区：
文献类型：
--
作者：
Chauhan, Pallavi;Swaegers, Janne;Hansson, Bengt
性染色体的进化，性别偏倚基因表达模式和剂量补偿，在早期有翅昆虫中知之甚少，如齿形昆虫。我们组装并注释了蓝尾豆娘（Ischnura elegans，蓝尾豆娘）的基因组，它和其他蜻蜓动物一样，具有雄性半对称的性别决定系统（X0雄性，XX雌性）。通过鉴定秀丽隐杆线虫及其在其他昆虫基因组中的同源基因，我们发现齿形目昆虫的X染色体与包括鞘翅目昆虫在内的其他目昆虫的X染色体具有同源性。接下来，我们在成年秀丽隐杆线虫中发现了两性间x连锁基因的平衡表达，即剂量补偿的证据。最后，在性别决定途径的基因中，只有无果性基因被发现是x连锁的，而只有双性基因表现出性别偏倚的表达。本研究揭示了在相隔数亿年的昆虫目中存在着部分保守的性染色体合式和剂量补偿的独立进化。
The evolution of sex chromosomes, and patterns of sex-biased gene expression and dosage compensation, are poorly known among early winged insects such as odonates. We assembled and annotated the genome of Ischnura elegans (blue-tailed damselfly), which, like other odonates, has a male-hemigametic sex-determining system (X0 males, XX females). By identifying X-linked genes in I. elegans and their orthologs in other insect genomes, we found homologies between the X chromosome in odonates and chromosomes of other orders, including the X chromosome in Coleoptera. Next, we showed balanced expression of X-linked genes between sexes in adult I. elegans, i.e. evidence of dosage compensation. Finally, among the genes in the sex-determining pathway only fruitless was found to be X-linked, while only doublesex showed sex-biased expression. This study reveals partly conserved sex chromosome synteny and independent evolution of dosage compensation among insect orders separated by several hundred million years of evolutionary history.