Roles of a putative DopEcR-like gene in temperature stress response and development of the oriental fruit fly, Bactrocera dorsalis.

Background: The Drosophila melanogaster gene CG18314 encodes a DopEcR, which is implicated in various physiological functions. However, genome-wide analyses of insect neurohormone GPCRs have identified CG13579 and its orthologs as putative DopEcRs, whose functions remain largely unexplored.

Results: We here identified an ortholog of CG13579 in the oriental fruit fly, Bactrocera dorsalis. Phylogenetic analysis classified these genes as dopamine/ecdysteroid receptors (DopEcR). RT-qPCR analysis revealed that expression of the BdorDopEcR-like gene significantly increased under thermal stress. We successfully generated a BdorDopEcR-like knockout strain from the wild-type (WT) background using the CRISPR/Cas9 system. Compared with WT flies, the Bdor-DopEcR-like mutants exhibited shorter heat knockdown time and prolonged chill coma recovery times. Upon exposure to extreme heat, seizure-like behaviors were significantly more frequent in mutants than in WT individuals. Moreover, the survival rate of Bdor-DopEcR-like flies under extreme high temperatures was markedly reduced compared with that of WT flies. Additionally, knockout of Bdor-DopEcR-like led to decreased rates of egg hatching, pupation, and adult eclosion.

Conclusion: These findings provide valuable insights into the physiological functions of DopEcR-like receptors in insect thermal stress tolerance and developmental processes. © 2025 Society of Chemical Industry.