Yang Hua, Su Ting, Yang Wei, Yang Chunping, Lu Lin, Chen Zhangming
Key Laboratory of Ecological Forestry Engineering of Sichuan Province, College of Forestry, Sichuan Agricultural University, Chengdu, China.
PLoS One. 2017 Jun 29;12(6):e0179807. doi: 10.1371/journal.pone.0179807. eCollection 2017.
Cyrtotrachelus buqueti is an extremely harmful bamboo borer, and the larvae of this pest attack clumping bamboo shoots. Pheromone-binding proteins (PBPs) play an important role in identifying insect sex pheromones, but the C. buqueti genome is not readily available for PBP analysis. Developmental transcriptomes of eggs, larvae from the first instar to the prepupal stage, pupae, and adults (females and males) from emergence to mating were built by RNA sequencing (RNA-Seq) in the present study to establish a sequence background of C. buqueti to help understand PBPs. Approximately 164.8 million clean reads were obtained and annotated into 108,854 transcripts. These were assembled into 24,338, 21,597, 24,798, 21,886, 24,642, and 83,115 unigenes for eggs, larvae, pupae, females, males, and the combined datasets, respectively. Unigenes were annotated against NCBI non-redundant protein sequences, NCBI non-redundant nucleotide sequences, Gene Ontology (GO), Protein family, Clusters of Orthologous Groups of Proteins/ Clusters of Eukaryotic Orthologous Groups (KOG), Swiss-Prot, and KEGG Orthology databases. A total of 17,213 unigenes were annotated into 55 sub-categories belonging to three main GO categories; 10,672 unigenes were classified into 26 functional categories by KOG classification, and 8,063 unigenes were classified into five functional KEGG categories. RSEM software for RNA sequencing showed that 4,816, 3,176, 3,661, 2,898, 4,316, 8,019, 7,273, 5,922, 5,844, and 4,570 genes were differentially expressed between larvae and males, larvae and eggs, larvae and pupae, larvae and females, males and females, males and eggs, males and pupae, females and eggs, females and pupae, and eggs and pupae, respectively. Of these, three were confirmed to be significantly differentially expressed between larvae, females, and males. Furthermore, PBP Cbuq7577_g1 was highly expressed in the antenna of males. A comprehensive sequence resource of a desirable quality was constructed from developmental transcriptomes of C. buqueti eggs, larvae, pupae, and adults. This work enriches the genomic data of C. buqueti, and facilitates our understanding of its metamorphosis, development, and response to environmental change. The identified candidate PBP Cbuq7577_g1 might play a crucial role in identifying sex pheromones, and could be used as a targeted gene to control C. buqueti numbers by disrupting sex pheromone communication.
竹大象甲是一种极具危害性的竹子蛀虫，这种害虫的幼虫会蛀食丛生竹笋。信息素结合蛋白（PBPs）在识别昆虫性信息素方面发挥着重要作用，但目前尚无竹大象甲基因组用于PBP分析。在本研究中，通过RNA测序（RNA-Seq）构建了竹大象甲从卵、一龄幼虫到预蛹期的幼虫、蛹以及羽化至交配阶段的成虫（雌性和雄性）的发育转录组，以建立竹大象甲的序列背景，从而有助于了解PBPs。共获得约1.648亿条clean reads，并注释为108,854条转录本。这些转录本分别组装成24,338、21,597、24,798、21,886、24,642和83,115条单基因，分别对应卵、幼虫、蛹、雌性、雄性以及合并数据集。将单基因与NCBI非冗余蛋白质序列、NCBI非冗余核苷酸序列、基因本体（GO）、蛋白质家族、直系同源蛋白簇/真核生物直系同源蛋白簇（KOG）、Swiss-Prot和KEGG直系同源数据库进行注释。共有17,213条单基因被注释到属于三个主要GO类别的55个子类别中；10,672条单基因通过KOG分类被分为26个功能类别，8,063条单基因被分为5个功能KEGG类别。用于RNA测序的RSEM软件显示，幼虫与雄性、幼虫与卵、幼虫与蛹、幼虫与雌性、雄性与雌性、雄性与卵、雄性与蛹、雌性与卵、雌性与蛹以及卵与蛹之间分别有4,816、3,176、3,661、2,898、4,316、8,019、7,273、5,922、5,844和4,570个基因差异表达。其中，有三个基因在幼虫、雌性和雄性之间被证实存在显著差异表达。此外，PBP Cbuq7577_g1在雄性触角中高表达。利用竹大象甲卵、幼虫、蛹和成虫的发育转录组构建了高质量的综合序列资源。这项工作丰富了竹大象甲的基因组数据，有助于我们了解其变态、发育以及对环境变化的反应。鉴定出的候选PBP Cbuq7577_g1可能在识别性信息素方面发挥关键作用，并可作为通过破坏性信息素通讯来控制竹大象甲数量的靶向基因。
