The Pkd2 gene regulates reproduction and mediates temperature stress tolerance in the oriental fruit fly, Bactrocera dorsalis

BACKGROUND Most insect species possess either a single TRP‐polycystin 2 ( TRPP2 / Pkd2 ) gene or lack it entirely. In contrast, the family Tephritidae uniquely possesses two Pkd2 members whose functional roles remain largely unexplored. Here, we investigated the physiological functions of Pkd2‐1 and Pkd2‐2 in the tephritid pest Bactrocera dorsalis using CRISPR/Cas9‐mediated gene knockout. RESULTS Homozygous knockout lines for BdorPkd2‐1 and BdorPkd2‐2 were generated from wild‐type (WT) flies using the CRISPR/Cas9 system. Eggs from BdorPkd2‐1 knockout mutants failed to undergo normal embryonic development, resulting in a 0% hatch rate. In contrast, deletion of BdorPkd2‐2 significantly reduced the adult mating rate, fecundity, and egg hatchability. Compared with WT flies, BdorPkd2‐2 −/− mutants exhibited shorter heat‐knockdown times and longer chill‐coma recovery times. Furthermore, adult survival rates for BdorPkd2‐2 −/− mutants were significantly reduced under normal and extreme temperatures. CONCLUSION BdorPkd2‐1 is essential for embryonic development, whereas BdorPkd2‐2 plays a critical role in reproduction and thermal stress tolerance in B. dorsalis . These findings advance our understanding of Pkd2 function in tephritid pests and suggest novel strategies for pest control by targeting reproduction or stress responses.