RESUMEN
Mancozeb (MZ) is a broad-spectrum fungicide used worldwide in several crops. Neurological disorders in humans and animals have been associated with exposure to this compound by mechanisms still not fully understood. Drosophila melanogaster represents a reliable model in toxicological studies, presenting genetic and biochemical similarities with mammals. In this study, D. melanogaster flies were exposed for 15 days to MZ through the food (5 and 10 mg/mL). After that period, the efficiency of mitochondrial respiration complexes and metabolic markers were analyzed and evaluated. Flies presented weight loss, lower glucose, trehalose, and glycogen levels, and augmented levels of triglycerides concerning control (non-treated group). Acetyl-CoA Synthetase (ACeCS-1) and Acyl-Coenzyme Synthetase (ACSL1) contents were unchanged by MZ treatment. Mitochondrial respiration of flies was targeted by MZ treatment, evidenced by a decrease in oxygen consumption and bioenergetics rate and inhibition in mitochondrial complexes I/II. These results suppose that an impairment in mitochondrial respiration jointly with reduced levels of energetic substrates might be a mechanism involved in MZ deleterious effects, possibly by the limitation of ATP's availability, necessary for essential cellular processes.
RESUMEN
The microbiota and the functional genes actively involved in the process of breakdown and utilization of pollen grains in beebread and bee guts are not yet understood. The aim of this work was to assess the diversity and community structure of bacteria and archaea in Africanized honeybee guts and beebread as well as to predict the genes involved in the microbial bioprocessing of pollen using state of the art 'post-light' based sequencing technology. A total of 11 bacterial phyla were found within bee guts and 10 bacterial phyla were found within beebread. Although the phylum level comparison shows most phyla in common, a deeper phylogenetic analysis showed greater variation of taxonomic composition. The families Enterobacteriaceae, Ricketsiaceae, Spiroplasmataceae and Bacillaceae, were the main groups responsible for the specificity of the bee gut while the main families responsible for the specificity of the beebread were Neisseriaceae, Flavobacteriaceae, Acetobacteraceae and Lactobacillaceae. In terms of microbial community structure, the analysis showed that the communities from the two environments were quite different from each other with only 7 % of species-level taxa shared between bee gut and beebread. The results indicated the presence of a highly specialized and well-adapted microbiota within each bee gut and beebread. The beebread community included a greater relative abundance of genes related to amino acid, carbohydrate, and lipid metabolism, suggesting that pollen biodegradation predominantly occurs in the beebread. These results suggests a complex and important relationship between honeybee nutrition and their microbial communities.