Paula Débora Pires, Andow David A, Timbó Renata Velozo, Sujii Edison R, Pires Carmen S S, Fontes Eliana M G
Department of Biological Control, Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
Department of Entomology, University of Minnesota, St. Paul, Minnesota, United States of America.
PLoS One. 2014 Apr 18;9(4):e95422. doi: 10.1371/journal.pone.0095422. eCollection 2014.
Research on non-target effects of transgenic crop plants has focused primarily on bitrophic, tritrophic and indirect effects of entomotoxins from Bacillus thuringiensis, but little work has considered intergenerational transfer of Cry proteins. This work reports a lepidopteran (Chlosyne lacinia) taking up a Bt entomotoxin when exposed to sublethal or low concentrations, transferring the entomotoxin to eggs, and having adverse effects on the first filial generation (F1) offspring. Two bioassays were conducted using a sublethal concentration of toxin (100.0 ng/µl Cry1Ac) for adults and a concentration equal to the LC10 (2.0 ng/µl Cry1Ac) for larvae. Cry1Ac is the most common entomotoxin expressed in Bt cotton in Brazil. In the adult diet bioassay there was no adverse effect on the parental generation (P0) adults, but the F1 larvae had higher mortality and longer development time compared to F1 larvae of parents that did not ingest Cry1Ac. For the 3rd instar larvae, there was no measurable effect on the P0 larvae, pupae and adults, but the F1 larvae had higher mortality and longer development time. Using chemiluminescent Western Blot, Cry1Ac was detected in F1 eggs laid by P0 butterflies from both bioassays. Our study indicates that, at least for this species and these experimental conditions, a ∼65 kDa insecticidal protein can be taken up and transferred to descendants where it can increase mortality and development time.
对转基因作物非靶标效应的研究主要集中在苏云金芽孢杆菌昆虫毒素的双营养、三营养和间接效应上，但很少有研究考虑Cry蛋白的代际转移。这项研究报告了一种鳞翅目昆虫（Chlosyne lacinia）在接触亚致死或低浓度毒素时摄取Bt昆虫毒素，将该毒素转移到卵中，并对第一代（F1）后代产生不利影响。使用亚致死浓度的毒素（100.0 ng/µl Cry1Ac）处理成虫，以及使用等于LC10的浓度（2.0 ng/µl Cry1Ac）处理幼虫，进行了两项生物测定。Cry1Ac是巴西Bt棉花中表达最常见的昆虫毒素。在成虫饮食生物测定中，对亲代（P0）成虫没有不利影响，但与未摄取Cry1Ac的亲代的F1幼虫相比，F1幼虫的死亡率更高，发育时间更长。对于三龄幼虫，对P0幼虫、蛹和成虫没有可测量的影响，但F1幼虫的死亡率更高，发育时间更长。使用化学发光免疫印迹法，在两项生物测定中P0蝴蝶所产的F1卵中均检测到了Cry1Ac。我们的研究表明，至少对于该物种和这些实验条件而言，一种约65 kDa的杀虫蛋白可以被摄取并转移给后代，在后代中它会增加死亡率和延长发育时间。
