Dominant point mutation in a tetraspanin gene associated with field-evolved resistance of cotton bollworm to transgenic Bt cotton

Authors: Lin Jin, Jing Wang, Fang Guan, Jianpeng Zhang, Shan Yu, Shaoyan Liu, Yuanyuan Xue, Lingli Li, Shuwen Wu, Xingliang Wang, Yihua Yang, Heba Abdelgaffar, Juan Luis Jurat‐Fuentes, Bruce E. Tabashnik, Yidong Wu - Proceedings of the National Academy of Sciences, PNAS 2018 cited by 163

), a devastating global pest, confers dominant resistance to Cry1Ac, the sole Bt protein produced by transgenic cotton planted in China. We found the mutation using a genome-wide association study, followed by fine-scale genetic mapping and DNA sequence comparisons between resistant and susceptible strains. CRISPR/Cas9 knockout of the tetraspanin gene restored susceptibility to a resistant strain, whereas inserting the mutation conferred 125-fold resistance in a susceptible strain. DNA screening of moths captured from 23 field sites in six provinces of northern China revealed a 100-fold increase in the frequency of this mutation, from 0.001 in 2006 to 0.10 in 2016. The correspondence between the observed trajectory of the mutation and the trajectory predicted from simulation modeling shows that the dominance of the mutation accelerated adaptation. Proactive identification and tracking of the tetraspanin mutation demonstrate the potential for genomic analysis, gene editing, and molecular monitoring to improve management of resistance.