Yao Jianxiu, Buschman Lawrent L, Lu Nanyan, Khajuria Chitvan, Zhu Kun Yan
Department of Entomology, 123 Waters Hall, Kansas State University, Manhattan, KS 66506, USA.
Bioinformatics Center, Kansas State University, Manhattan, KS 66506, USA.
Toxins (Basel). 2014 Apr 3;6(4):1274-94. doi: 10.3390/toxins6041274.
We developed a microarray based on 2895 unique transcripts assembled from 15,000 cDNA sequences from the European corn borer (Ostrinia nubilalis) larval gut. This microarray was used to monitor gene expression in early third-instar larvae of Bacillus thuringiensis (Bt)-susceptible O. nubilalis after 6 h feeding on diet, with or without the Bt Cry1Ab protoxin. We identified 174 transcripts, for which the expression was changed more than two-fold in the gut of the larvae fed Cry1Ab protoxin (p < 0.05), representing 80 down-regulated and 94 up-regulated transcripts. Among 174 differentially expressed transcripts, 13 transcripts putatively encode proteins that are potentially involved in Bt toxicity, and these transcripts include eight serine proteases, three aminopeptidases, one alkaline phosphatase, and one cadherin. The expressions of trypsin-like protease and three aminopeptidase transcripts were variable, but two potential Bt-binding proteins, alkaline phosphatase and cadherin were consistently up-regulated in larvae fed Cry1Ab protoxin. The significantly up and down-regulated transcripts may be involved in Cry1Ab toxicity by activation, degradation, toxin binding, and other related cellular responses. This study is a preliminary survey of Cry1Ab protoxin-induced transcriptional responses in O. nubilalis gut and our results are expected to help with further studies on Bt toxin-insect interactions at the molecular level.
我们基于从欧洲玉米螟（Ostrinia nubilalis）幼虫肠道的15000个cDNA序列组装得到的2895个独特转录本开发了一种微阵列。该微阵列用于监测对苏云金芽孢杆菌（Bt）敏感的欧洲玉米螟三龄初期幼虫在取食含或不含Bt Cry1Ab原毒素的饲料6小时后的基因表达。我们鉴定出174个转录本，其在取食Cry1Ab原毒素的幼虫肠道中的表达变化超过两倍（p < 0.05），其中80个转录本下调，94个转录本上调。在174个差异表达的转录本中，有13个转录本推测编码可能参与Bt毒性的蛋白质，这些转录本包括8个丝氨酸蛋白酶、3个氨肽酶、1个碱性磷酸酶和1个钙黏蛋白。类胰蛋白酶和3个氨肽酶转录本的表达存在差异，但两个潜在的Bt结合蛋白，碱性磷酸酶和钙黏蛋白在取食Cry1Ab原毒素的幼虫中持续上调。显著上调和下调的转录本可能通过激活、降解、毒素结合及其他相关细胞反应参与Cry1Ab毒性作用。本研究是对Cry1Ab原毒素诱导的欧洲玉米螟肠道转录反应的初步调查，我们的结果有望有助于在分子水平上进一步研究Bt毒素与昆虫的相互作用。
