Chronic exposure to glyphosate induces transcriptional changes in honey bee larva: a toxicogenomic study.

VAZQUEZ D; LATORRE-ESTIVALIS J; ONS SHEILA; FARINA WALTER M.

ENVIRONMENTAL POLLUTION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2020

0269-7491

The honey bee Apis mellifera is the most abundant managed pollinator in diverse crops23 worldwide. Consequently, it is exposed to a plethora of environmental stressors, among24 which are the agrochemicals. In agroecosystems, the herbicide glyphosate (GLY) is one of25 the most applied. In laboratory assessments, GLY affects the honey bee larval development26 by delaying its moulting, among other negative effects. However, it is still unknown how27 GLY affects larval physiology when there are no observable signs of toxicity. We carried28 out a longitudinal experimental design using the in vitro rearing procedure. Larvae were fed29 with food containing or not a sub-lethal dose of GLY in chronic exposure (120 h).30 Individuals without observable signs of toxicity were sampled and their gene expression31 profile was analyzed with a transcriptomic approach to compare between treatments. Even32 though 29% of larvae were asymptomatic in the exposed group, they showed33 transcriptional changes in several genes after the GLY chronic intake. A total of 1934 transcripts were found to be differentially expressed in the RNA-Seq experiment, mainly35 linked with defensive response and intermediary metabolism processes. Furthermore, the36 enriched functional categories in the transcriptome of the exposed asymptomatic larvae37 were linked with enzymes with catalytic and redox activity. Our results suggest an38 enhanced catabolism and oxidative metabolism in honey bee larvae as a consequence of the39 sub-lethal exposure to GLY, even in the absence of observable symptoms.