Project description:Methods currently available to estimate the post-mortem submerged interval (PMSI) of cadavers in water suffer from poor accuracy, being mostly based on morphological examination of the remains. Proteins present within bones have recently attracted more attention from researchers interested in the estimation of the post-mortem interval (PMI) in terrestrial environments. Despite the great potential of proteomic methods for PMI estimation, their application to aquatic environments has not yet been explored. In this study, we examined whether four different types of aquatic environment (tap water, saltwater, pond water and chlorinated water) affected the proteome of mice bones with increasing PMSIs (from zero to three weeks).
Project description:The aquatic midge, Chironomus tentans, is a keystone species in aquatic ecosystem and used as a model organism to assess chemicals toxicity in aquatic environment. To characterize midge’s cellular and molecular responses to pesticides, we established cDNA library with 10,000 cDNA elements representing 2,456 C. tentans unique genes. Blast2go identified 49 genes potentially involved in xenobiotics metabolism, including 24 cytochrome p450s (CYPs), 14 esterases (ESTs) and 11 glutathione-s-transferases (GSTs). Based on 2,456 unique genes, a cDNA microarray was developed to monitor gene expression profiles in 4th instar larvae under chlopyrifos (0.1 µg/L and 0.5 µg/L) and 1000 µg/L atrazine 48-hr exposure. We identified 149, 435 and 244 genes were significantly differentially expressed (p-value ≤0.05 with expression ratios ≥2.0) after 0.1 µg/L, 0.5 µg/L chlopyrifos, and 1000 µg/L atrazine application, respectively. Sixteen insect detoxification genes (11 CYPs, 3 GSTs and 2 esterases) were validated by qPCR and their expressions were significantly either up- or down-regulated under chlorpyrifos and atrazine exposure, especially the expression of 10 CYPs were significantly induced after chlopyrifos and atrazine exposure. The up-regulated CYPs might be involved in xenobiotic activation and/or degradation. Furthermore, we also found 5 differentially expressed hemoglobin genes. The expression changes of hemoglobins might be an adaption mechanism of C. tentans to hypoxic condition caused by xenobiotic exposure. This study provides a platform for further functional studies of pesticide-insect interactions in C. tentans.
