HGT is widespread in insects and contributes to male courtship in lepidopterans

Horizontal gene transfer (HGT) is an important evolutionary force shaping prokaryotic and eukaryotic ge-nomes. HGT-acquired genes have been sporadically reported in insects, a lineage containing >50% of ani-mals. We systematically examined HGT in 218 high-quality genomes of diverse insects and found that they acquired 1,410 genes exhibiting diverse functions, including many not previously reported, via 741 distinct transfers from non-metazoan donors. Lepidopterans had the highest average number of HGT-ac-quired genes. HGT-acquired genes containing introns exhibited substantially higher expression levels than genes lacking introns, suggesting that intron gains were likely involved in HGT adaptation. Lastly, we used the CRISPR-Cas9 system to edit the prevalent unreported gene LOC105383139, which was transferred into the last common ancestor of moths and butterflies. In diamondback moths, males lacking LOC105383139 courted females significantly less. We conclude that HGT has been a major contributor to in-sect adaptation.

Automated summary

Horizontal gene transfer (HGT) is a significant evolutionary force that plays a crucial role in insect adaptation. In this study, we systematically analyzed 218 high-quality insect genomes and identified 1,410 genes acquired through HGT from non-metazoan donors. Lepidopterans had the highest number of HGT-acquired genes. Genes with introns showed higher expression levels, suggesting the involvement of intron gains in HGT adaptation. Additionally, we successfully edited a prevalent but previously unreported HGT-acquired gene in diamondback moths, which was found to affect courtship behavior.