Immunity related genes in honey bees in response to synthetic acaricidal treatments

GARRIDO, PAULA MELISA; ANTÚNEZ, KARINA; MARIANA MARTÍN; MARTÍN PABLO PORRINI; MARTÍN JAVIER EGUARAS

Capital Federal

Congreso; International Congress on Invertebrate Pathology and Microbial Control and 45th Annual Meeting of the Society for Invertebrate Pathology; 2012

Society for Invertebrate Pathology

The mite Varroa destructor is an ectoparasite affecting honey bees worldwide, causing serious economic damage on beekeeping. Synthetic acaricides have been among the principal tools available to beekeepers for varroa management. Several studies have been shown its negative effects on honey bee physiology even at sub-lethal levels. Recent research suggests that those molecules strongly impact on immune signaling cascades and cellular immunity. However, toxicity studies at immune gene expression levels are few. In the present work, LC50 in six-day-old bees were determined for the following acaricides: tau-fluvalinate, flumethrin, amitraz and coumaphos. According to this obtained value, a group of individuals were treated and then processed for qt-PCR analysis. Transcript levels for the genes encoding the antimicrobial proteins hymenoptaecin and defensin, the immunity related proteins phenoloxidase and vitellogenin were assessed. Flumethrin significantly elevated the expression of hymenoptaecin and phenoloxidase. With respect defensin expression, differences became significant when coumaphos vs. flumethrin treated bees were compared, although no differences were detected when comparison was made with control bees. No significant changes were recorded in the expression levels of vitellogenin among bees treated with acaricides and control bees. This work constitutes the first report, under laboratory conditions, about induction of immune related genes in response to synthetic miticides. We discuss possible underlying mechanisms for these results and host susceptibility to different pathogens after acaricide exposure, since some of these molecules frequently have been found in apicultural matrices at high concentrations.