我们提出了蝗虫的第一个染色体水平基因组组装,蝗虫迁徙,最大的昆虫基因组之一。我们使用女性(XX)和男性(X0)之间的覆盖率差异来鉴定X染色体基因含量,并发现X染色体在体细胞组织中显示出完全的剂量补偿和睾丸表达基因的代表性不足。迁徙乳杆菌的X连锁基因含量在七个昆虫中高度保守,即直翅目,Odonata,相思,半翅目,神经翅目,鞘翅目,和双翅目,尽管有4亿年的分歧,但800Mb蝗虫X染色体与苍蝇祖先X染色体是同源的,表明基因含量高度相似的性染色体的重复起源,或X染色体的长期保守。我们使用X染色体的这种广泛守恒来测试Fast-X进化的时间动力学,并发现新的X连锁基因最近爆发进化的证据,与X保守基因的缓慢进化相反。
We present the first chromosome-level genome assembly of the grasshopper, Locusta migratoria, one of the largest insect genomes. We use coverage differences between females (XX) and males (X0) to identify the X Chromosome gene content, and find that the X Chromosome shows both complete dosage compensation in somatic tissues and an underrepresentation of testis-expressed genes. X-linked gene content from L. migratoria is highly conserved across seven insect orders, namely Orthoptera, Odonata, Phasmatodea, Hemiptera, Neuroptera, Coleoptera, and Diptera, and the 800 Mb grasshopper X Chromosome is homologous to the fly ancestral X Chromosome despite 400 million years of divergence, suggesting either repeated origin of sex chromosomes with highly similar gene content, or long-term conservation of the X Chromosome. We use this broad conservation of the X Chromosome to test for temporal dynamics to Fast-X evolution, and find evidence of a recent burst evolution for new X-linked genes in contrast to slow evolution of X-conserved genes.