Previous studies have confirmed HaCad (cadherin), HaABCC2 and HaABCC3 are functional receptors of Bt toxin Cry1Ac in cotton bollworm, Helicoverpa armigera. Aminopeptidase N1 (APN1) has been suggested as a putative receptor in several lepidopteran insects including H. armigera through evidence from RNAi‐based gene silencing approaches. In the current study, we tested the role of APNs in the mode of action of Bt toxins using CRISPR/Cas9‐mediated gene knockout. Three APN genes (HaAPN1, HaAPN2 and HaAPN5) were individually knocked out in a susceptible SCD strain of H. armigera to establish three homozygous knockout strains. Bioassay results showed that none of the three knockouts had significant changes in susceptibility to Cry1A or Cry2A toxins when compared with the SCD strain. This suggests that the three HaAPN genes we tested may not be critical in the mode of action of Cry1A or Cry2A toxins in H. armigera (see pages 440–448). Photo by Yi‐Dong Wu.

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封面说明

先前的研究已经证实，HaCad（钙黏着蛋白），HaABCC2和HaABCC3是棉铃虫棉铃虫中Bt毒素Cry1Ac的功能受体。通过基于RNAi的基因沉默方法的证据，氨基肽酶N1（APN1）被认为是包括鳞翅目棉铃虫在内的几种鳞翅目昆虫的推定受体。在本研究中，我们使用CRISPR / Cas9介导的基因敲除测试了APN在Bt毒素作用模式中的作用。三种APN基因（HaAPN1，HaAPN2和HaAPN5）分别在敏感的棉铃虫SCD菌株中敲除），以建立三种纯合的敲除菌株。生物测定结果表明，与SCD菌株相比，三个基因敲除对Cry1A或Cry2A毒素的敏感性均无明显变化。这表明我们测试的三个HaAPN基因对于棉铃虫中Cry1A或Cry2A毒素的作用方式可能不是关键的（请参见第440-448页）。吴宜东摄。