Transcriptomic insights on the ABC transporter gene family in the salmon louse Caligus rogercresseyi

Background  ATP-binding cassette (ABC) protein family encode for membrane proteins involved in the transport of various biomolecules through the cellular membrane. These proteins have been identified in all taxa and present important physiological functions, including the process of insecticide detoxification in arthropods. For that reason the ectoparasiteCaligus rogercresseyirepresents a model species for understanding the molecular underpinnings involved in insecticide drug resistance.  Methods  llumina sequencing was performed using sea lice exposed to 2 and 3 ppb of deltamethrin and azamethiphos. Contigs obtained fromde novoassembly were annotated by Blastx. RNA-Seq analysis was performed and validated by qPCR analysis.  Results  From the transcriptome database ofC. rogercresseyi, 57 putative members of ABC protein sequences were identified and phylogenetically classified into the eight subfamilies described for ABC transporters in arthropods. Transcriptomic profiles for ABC proteins subfamilies were evaluated throughoutC. rogercresseyidevelopment. Moreover, RNA-Seq analysis was performed for adult male and female salmon lice exposed to the delousing drugs azamethiphos and deltamethrin. High transcript levels of the ABCB and ABCC subfamilies were evidenced. Furthermore, SNPs mining was carried out for the ABC proteins sequences, revealing pivotal genomic information.  Conclusions  The present study gives a comprehensive transcriptome analysis of ABC proteins fromC. rogercresseyi,providing relevant information about transporter roles during ontogeny and in relation to delousing drug responses in salmon lice. This genomic information represents a valuable tool for pest management in the Chilean salmon aquaculture industry