Chávez-Mardones Jacqueline, Gallardo-Escárate Cristian
Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, P. O. Box 160-C, Concepción, Chile.
Mar Biotechnol (NY). 2015 Dec;17(6):793-810. doi: 10.1007/s10126-015-9661-9. Epub 2015 Aug 26.
Sea lice are one of the main parasites affecting the salmon aquaculture industry, causing significant economic losses worldwide. Increased resistance to traditional chemical treatments has created the need to find alternative control methods. Therefore, the objective of this study was to identify the transcriptome response of the salmon louse Caligus rogercresseyi to the delousing drug deltamethrin (AlphaMax™). Through bioassays with different concentrations of deltamethrin, adult salmon lice transcriptomes were sequenced from cDNA libraries in the MiSeq Illumina platform. A total of 78 million reads for females and males were assembled in 30,212 and 38,536 contigs, respectively. De novo assembly yielded 86,878 high-quality contigs and, based on published data, it was possible to annotate and identify relevant genes involved in several biological processes. RNA-seq analysis in conjunction with heatmap hierarchical clustering evidenced that pyrethroids modify the ectoparasitic transcriptome in adults, affecting molecular processes associated with the nervous system, cuticle formation, oxidative stress, reproduction, and metabolism, among others. Furthermore, sex-related transcriptome differences were evidenced. Specifically, 534 and 1033 exclusive transcripts were identified for males and females, respectively, and 154 were shared between sexes. For males, estradiol 17-beta-dehydrogenase, sphingolipid delta4-desaturase DES1, ketosamine-3-kinase, and arylsulfatase A, among others, were discovered, while for females, vitellogenin 1, glycoprotein G, transaldolase, and nitric oxide synthase were among those identified. The shared transcripts included annotations for tropomyosin, γ-crystallin A, glutamate receptor-metabotropic, glutathione S-transferase, and carboxipeptidase B. The present study reveals that deltamethrin generates a complex transcriptome response in C. rogercresseyi, thus providing valuable genomic information for developing new delousing drugs.
海虱是影响鲑鱼养殖业的主要寄生虫之一，在全球范围内造成了重大经济损失。对传统化学处理方法的耐药性增加，使得寻找替代控制方法成为必要。因此，本研究的目的是确定鲑鱼虱Caligus rogercresseyi对除虱药物溴氰菊酯（AlphaMax™）的转录组反应。通过对不同浓度溴氰菊酯进行生物测定，在Illumina MiSeq平台上从cDNA文库对成年鲑鱼虱的转录组进行测序。雌性和雄性分别共有7800万个读数，组装成30212和38536个重叠群。从头组装产生了86878个高质量重叠群，并且基于已发表的数据，可以注释和识别参与多个生物学过程的相关基因。结合热图层次聚类的RNA测序分析表明，拟除虫菊酯会改变成年体外寄生虫的转录组，影响与神经系统、表皮形成、氧化应激、繁殖和代谢等相关的分子过程。此外，还证明了与性别相关的转录组差异。具体而言，分别为雄性和雌性鉴定出534个和1033个独特转录本，两性之间共有154个转录本。在雄性中，发现了17-β-雌二醇脱氢酶、鞘脂δ4-去饱和酶DES1、酮胺-3-激酶和芳基硫酸酯酶A等，而在雌性中，鉴定出的有卵黄蛋白原1、糖蛋白G、转醛醇酶和一氧化氮合酶等。共享的转录本包括原肌球蛋白、γ-晶状体蛋白A、代谢型谷氨酸受体、谷胱甘肽S-转移酶和羧肽酶B的注释。本研究表明，溴氰菊酯在C. rogercresseyi中产生复杂的转录组反应，从而为开发新的除虱药物提供了有价值的基因组信息。
