Differential transcriptome analysis reveals genes related to cold tolerance in seabuckthorn carpenter moth, Eogystia hippophaecolus

Seabuckthorn carpenter moth, Eogystia hippophaecolus (Lepidoptera: Cossidae), is an important pest of sea buckthorn (Hippophae rhamnoides), which is a shrub that has significant ecological and economic value in China. E. hippophaecolus is highly cold tolerant, but limited studies have been conducted to elucidate the molecular mechanisms underlying its cold resistance. Here we sequenced the E. hippophaecolus transcriptome using RNA-Seq technology and performed de novo assembly from the short paired-end reads. We investigated the larval response to cold stress by comparing gene expression profiles between treatments. We obtained 118,034 unigenes, of which 22,161 were annotated with gene descriptions, conserved domains, gene ontology terms, and metabolic pathways. These resulted in 57 GO terms and 193 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. By comparing transcriptome profiles for differential gene expression, we identified many differentially expressed proteins and genes, including heat shock proteins and cuticular proteins which have previously been reported to be involved in cold resistance of insects. This study provides a global transcriptome analysis and an assessment of differential gene expression in E. hippophaecolus under cold stress. We found seven differential expressed genes in common between developmental stages, which were verified with qPCR. Our findings facilitate future genomic studies aimed at improving our understanding of the molecular mechanisms underlying the response of insects to low temperatures.

海松树钻蛀蛾，即Eogystia hippophaecolus（鳞翅目：卷蛾科），为海松（Hippophae rhamnoides）的重要害虫。海松在中国具有显著的生态和经济价值。E. hippophaecolus对低温具有高度耐受性，然而，关于其抗寒分子机理的研究尚显不足。本研究采用RNA-Seq技术对E. hippophaecolus转录组进行测序，并从短双端配对读段中进行了从头组装。通过比较处理组间的基因表达谱，我们研究了幼虫对低温胁迫的响应。我们获得了118,034个非冗余基因（unigenes），其中22,161个基因被注释为基因描述、保守结构域、基因本体术语和代谢途径。这些注释结果产生了57个基因本体术语和193个京都基因与基因组百科全书（KEGG）通路。通过比较差异表达基因的转录组特征，我们鉴定了许多差异表达的蛋白质和基因，包括先前报道的参与昆虫抗寒的热休克蛋白和几丁质蛋白。本研究对E. hippophaecolus在低温胁迫下的全局转录组进行了分析，并对差异基因表达进行了评估。我们发现，在发育阶段之间存在七个共同的差异表达基因，并通过实时荧光定量PCR进行了验证。我们的研究结果有助于未来开展旨在加深对昆虫低温响应分子机理理解的基因组学研究。