Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
BMC Genomics. 2013 Aug 28;14:582. doi: 10.1186/1471-2164-14-582.
Cotton bollworm (Helicoverpa armigera) and oriental tobacco budworm (Helicoverpa assulta) are noctuid sibling species. Under artificial manipulation, they can mate and produce fertile offspring. As serious agricultural insect pests, cotton bollworms are euryphagous insects, but oriental tobacco budworms are oligophagous insects. To identify the differentially expressed genes that affect host recognition and host adaptation between the two species, we constructed digital gene expression tag profiles for four developmental stages of the two species. High-throughput sequencing results indicated that we have got more than 23 million 17nt clean tags from both species, respectively. The number of unique clean tags was nearly same in both species (approximately 357,000).
According to the gene annotation results, we identified 83 and 68 olfaction related transcripts from H. armigera and H. assulta, respectively. At the same time, 1137 and 1138 transcripts of digestion enzymes were identified from the two species. Among the olfaction related transcripts, more odorant binding protein and G protein-coupled receptor were identified in H. armigera than in H. assulta. Among the digestion enzymes, there are more detoxification enzyme, e.g. P450, carboxypeptidase and ATPase in H. assulta than in H. armigera. These differences partially explain that because of the narrow host plant range of H. assulta, more detoxification enzymes would help them increase the food detoxification and utilization efficiency.
This study supplied some differentially expressed genes affecting host selection and adaptation between the two sibling species. These genes will be useful information for studying on the evolution of host plant selection. It also provides some important target genes for insect species-specific control by RNAi technology.
棉铃虫（Helicoverpa armigera）和烟实夜蛾（Helicoverpa assulta）是夜蛾科的近缘种。在人为操纵下，它们可以交配并产生可育后代。作为严重的农业害虫，棉铃虫是广食性昆虫，而烟实夜蛾是寡食性昆虫。为了鉴定影响两种昆虫宿主识别和适应的差异表达基因，我们构建了两种昆虫四个发育阶段的数字基因表达标签图谱。高通量测序结果表明，我们从两个物种中分别获得了超过 2300 万个 17nt 清洁标签。两个物种的独特清洁标签数量几乎相同（约 357000 个）。
根据基因注释结果，我们分别从棉铃虫和烟实夜蛾中鉴定出 83 个和 68 个嗅觉相关转录本。同时，从两个物种中鉴定出 1137 个和 1138 个消化酶转录本。在嗅觉相关转录本中，棉铃虫中鉴定出的气味结合蛋白和 G 蛋白偶联受体多于烟实夜蛾。在消化酶中，烟实夜蛾中的解毒酶，如 P450、羧肽酶和 ATP 酶，多于棉铃虫。这些差异部分解释了为什么烟实夜蛾的寄主植物范围狭窄，更多的解毒酶可以帮助它们提高食物解毒和利用效率。
本研究为研究宿主植物选择的进化提供了一些影响两种近缘种宿主选择和适应的差异表达基因。这些基因将为研究昆虫种间特异性控制的 RNAi 技术提供有用的信息。
