Epistasis confers resistance to Bt toxin Cry1Ac in the cotton bollworm.
Epistasis confers resistance to Bt toxin Cry1Ac in the cotton bollworm.
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上位性赋予棉铃虫对 Bt 毒素 Cry1Ac 的抗性
DOI：
10.1111/eva.12598
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发表时间：
2018-06
影响因子：
4.1
通讯作者：
Wu Y
中科院分区：
文献类型：
--
作者：
Gao M;Wang X;Yang Y;Tabashnik BE;Wu Y
害虫抗药性的进化降低了从苏云金芽孢杆菌(Bt)产生杀虫蛋白的广泛种植的转基因作物的好处。以前的工作表明，对转基因棉花产生的Bt毒素Cry1Ac的抗性可以通过突变破坏幼虫中肠中结合这种Bt毒素的钙粘蛋白蛋白来实现。然而，钙粘附素基因和其他基因之间的上位性相互作用的可能性几乎没有受到关注。在这里，我们报告了上位性赋予棉铃虫对Cry1Ac的抗性的证据，棉铃虫是世界上最具破坏性的作物害虫之一。品系LF256对Cry1Ac的抗性来源于田间捕获的雄性品系，与感病品系SCD相比具有常染色体、隐性和220倍的抗性。我们通过将LF256与一株对Cry1Ac的抗性由钙粘蛋白基因HaCad上的隐性等位基因赋予的菌株杂交，进行了等位基因的互补测试。由此产生的F1后代是抗病的，这表明LF256对Cry1Ac的抗性也是由该基因座的抗性等位基因决定的。然而，LF256的HaCad氨基酸序列缺乏插入和缺失，并且在LF256和敏感株之间没有一致的差异。此外，LF256中的大多数钙粘蛋白等位基因不是来自野外捕获的雄性。此外，抗Cry1Ac与LF256的HaCad基因座没有遗传连锁关系。此外，LF256与敏感株在HaCad转录本、钙粘蛋白蛋白水平以及Cry1Ac与钙粘蛋白的结合水平上相似。总体而言，这些结果表明HaCad与LF256中一个未知的第二个基因座之间的上位性导致了互补测试中观察到的F1后代的抗性。观察到的上位性对于解释广泛用于监测和分析抗性的F1筛选的结果以及加速抗性进化的潜力具有重要意义。
Evolution of resistance by insect pests reduces the benefits of extensively cultivated transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt). Previous work showed that resistance to Bt toxin Cry1Ac, which is produced by transgenic cotton, can be conferred by mutations disrupting a cadherin protein that binds this Bt toxin in the larval midgut. However, the potential for epistatic interactions between the cadherin gene and other genes has received little attention. Here, we report evidence of epistasis conferring resistance to Cry1Ac in the cotton bollworm, Helicoverpa armigera, one of the world's most devastating crop pests. Resistance to Cry1Ac in strain LF256 originated from a field‐captured male and was autosomal, recessive, and 220‐fold relative to susceptible strain SCD. We conducted complementation tests for allelism by crossing LF256 with a strain in which resistance to Cry1Ac is conferred by a recessive allele at the cadherin locus HaCad. The resulting F1 offspring were resistant, suggesting that resistance to Cry1Ac in LF256 is also conferred by resistance alleles at this locus. However, the HaCad amino acid sequence in LF256 lacked insertions and deletions, and did not differ consistently between LF256 and a susceptible strain. In addition, most of the cadherin alleles in LF256 were not derived from the field‐captured male. Moreover, Cry1Ac resistance was not genetically linked with the HaCad locus in LF256. Furthermore, LF256 and the susceptible strain were similar in levels of HaCad transcript, cadherin protein, and binding of Cry1Ac to cadherin. Overall, the results imply that epistasis between HaCad and an unknown second locus in LF256 yielded the observed resistance in the F1 progeny from the complementation test. The observed epistasis has important implications for interpreting results of the F1 screen used widely to monitor and analyze resistance, as well as the potential to accelerate evolution of resistance.
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影响因子：
4.5
作者：
Gahan LJ;Pauchet Y;Vogel H;Heckel DG
通讯作者：
Heckel DG
影响因子：
56.9
作者：
KAJIWARA, K;BERSON, EL;DRYJA, TP
通讯作者：
DRYJA, TP
顺式介导的与棉铃虫 Bt 抗性相关的胰蛋白酶基因的下调
影响因子：
4.6
作者：
Liu C;Xiao Y;Li X;Oppert B;Tabashnik BE;Wu K
通讯作者：
Wu K
影响因子：
3.7
作者：
Dively GP;Venugopal PD;Finkenbinder C
通讯作者：
Finkenbinder C
影响因子：
5.3
作者：
Downes, Sharon;Walsh, Tom;Tay, Wee Tek
通讯作者：
Tay, Wee Tek