Perkin Lindsey C, Oppert Brenda
Southern Plains Agricultural Research Center, USDA, Agricultural Research Service, College Station, TX, United States of America.
Center for Grain and Animal Health Research, USDA, Agricultural Research Service, Manhattan, KS, United States of America.
PeerJ. 2019 May 23;7:e6946. doi: 10.7717/peerj.6946. eCollection 2019.
The red flour beetle, , is a major agricultural pest of post-harvest products and stored grain. Control of in stored products and grain is primarily by fumigants and sprays, but insecticide resistance is a major problem, and new control strategies are needed. is a genetic model for coleopterans, and the reference genome can be used for discovery of candidate gene targets for molecular-based control, such as RNA interference. Gene targets need to be pest specific, and ideally, they are expressed at low levels for successful control. Therefore, we sequenced the transcriptome of four major life stages of , sorted data into groups based on high or low expression levels, and compared relative gene expression among all life stages. We narrowed our candidate gene list to a cuticle protein gene (CPG) for further analysis. We found that the CPG sequence was unique to and expressed only in the larval stage. RNA interference targeting CPG in newly-emerged larvae caused a significant ( < 0.05) decrease in CPG expression (1,491-fold) compared to control larvae and 64% mortality over 18 d. RNA-Seq of survivors after 18 d identified changes in the expression of other genes as well, including 52 long noncoding RNAs. Expression of three additional cuticle protein genes were increased and two chitinase genes were decreased in response to injection of CPG dsRNA. The data demonstrate that RNA-Seq can identify genes important for insect survival and thus may be used to develop novel biologically-based insect control products.
赤拟谷盗是收获后产品和储存谷物的主要农业害虫。控制储存产品和谷物中的赤拟谷盗主要依靠熏蒸剂和喷雾剂，但抗药性是一个主要问题，因此需要新的控制策略。赤拟谷盗是鞘翅目昆虫的遗传模型，其参考基因组可用于发现基于分子控制的候选基因靶点，如RNA干扰。基因靶点需要是害虫特异性的，理想情况下，它们以低水平表达以实现成功控制。因此，我们对赤拟谷盗四个主要生命阶段的转录组进行了测序，根据高表达或低表达水平对数据进行分组，并比较了所有生命阶段之间的相对基因表达。我们将候选基因列表缩小到一个表皮蛋白基因（CPG）进行进一步分析。我们发现CPG序列是赤拟谷盗特有的，并且仅在幼虫阶段表达。与对照幼虫相比，针对新出现幼虫的CPG进行RNA干扰导致CPG表达显著降低（P < 0.05）（1491倍），并且在18天内死亡率达到64%。18天后对存活者进行RNA测序还发现了其他基因表达的变化，包括52个长链非编码RNA。注射CPG双链RNA后，另外三个表皮蛋白基因的表达增加，两个几丁质酶基因的表达降低。这些数据表明RNA测序可以识别对昆虫存活重要的基因，因此可用于开发新型基于生物学的昆虫控制产品。
