Journal of Aquaculture Research & Development

Abstract

Molecular Characterization and Transcription Analysis of P-Glycoprotein Gene from the Salmon Louse Caligus rogercresseyi

Valentina Valenzuela-Muñoz, Gustavo Nuñez-Acuña and Cristian Gallardo-Escárate

Despite the efforts to manage the infestation Caligus rogercresseyi on salmon species, overuse of chemical antiparasites such as avermectins, organophosphates and pyrethroids have increasingly generated drug resistance, impacting on the efficacy of salmon lice control measures. So far, previous reports have evidenced that the ATPbinding cassette transporter P-glycoprotein (Pgp) is a candidate gene implicated in the response of salmon lice to neurotoxins. However, transcription patterns of Pgp in presence of pyrethroids and the expression pattern during the ontogenetic stages are still not complete elucidated. Herein, this study characterizes the Pgp mRNA from C. rogercresseyi (Cr-Pgp) and evaluates the transcription expression in during its lifecycle, and also in adults exposed to the antiparasitic drug deltamethrin (AlphaMax). The molecular characterization of Cr-Pgp showed a complete sequence of 4,730 bp, containing a 5’UTR of 56 bp, 3’UTR of 833 bp, and open reading frame (ORF) of 3,840 bp encoding for 1,280 amino acids. Interestingly, eleven SNPs were identified, being two of them nonsynonymous polymorphisms. Cr-Pgp transcription expression was evaluated in conjunction with cytochrome P450 due its wellestablished role as key molecule in drug detoxifications. Herein, Cr-Pgp transcription was mainly associated to adult females than males exposed to deltamethrin, which was also linked with cytochrome P450 expression in adult females at 2 ppb of deltamethrin. This study suggests that Cr-Pgp gene is involved in pyrethroid detoxification and evidences specific expression patterns related to developmental stages, as well as provides novel SNPs that could be associated with resistance/susceptibility to delousing drugs