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Hydrogen peroxide modulates antioxidant system transcription, evidencing sex‐dependent responses in Caligus rogercresseyi
Author(s) -
ChávezMardones Jacqueline,
Asencio Gladys,
Latuz Susana,
GallardoEscárate Cristian
Publication year - 2017
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/are.12939
Subject(s) - biology , antioxidant , hydrogen peroxide , antiparasitic agent , antiparasitic , bioassay , hemolymph , gene expression , gene , toxicology , pharmacology , biochemistry , ecology , medicine , pathology
Hydrogen peroxide (H 2 O 2 ) is a non‐pharmacological antiparasitic used to control adult copepodid ectoparasites in salmonid farming worldwide. Its functional mechanism is based on forming bubbles in the haemolymph and tissues, detaching the parasite from the host. However, to date there is no information on the molecular effects of H 2 O 2 . This study evaluated the modulation of 12 genes associated with the antioxidant system in Caligus rogercresseyi exposed to three concentrations of H 2 O 2 as an antiparasitic agent. Bioassay results showed that sea lice survival was 69%, 47% and 15% for H 2 O 2 doses of 1000, 1500 and 2000 mg L −1 respectively. The ratio of surviving males to females provided evidence that females were less sensitive to all evaluated conditions, and at a dose of 2000 mg L −1 , all surviving sea lice were female. Transcriptional analysis of antioxidant genes revealed that the three H 2 O 2 concentrations exerted differentiated effects on each sex. In females, a concentration of 1500 mg L −1 increased the gene expression of Cr PRX 2 , Cr GST 1 , Cr GST ‐ like and Cr GST ‐kappa 1 . For males, concentrations of 1000 and 2000 mg L −1 modulated the expression of Cr PHGP 1 , Cr CAT , Cr SOD , CrSe‐ GPX and Cr FERR . Global transcription expression evidenced that female sea lice generated a lower transcriptional response to H 2 O 2 as compared to males, and this response was correlated with lower accumulated mortality. These results suggest that H 2 O 2 modulates enzymes of the antioxidant system and that a sex‐specific response occurs to the oxidative stress generated by this pesticide.