Mission and goals
Generation of knowledge/tools useful for protection as well as management of ecosystem integrity and to advance the understanding of ecotoxicological problems across different ecological strata at cellular, genetic and organismal levels in order to improve environmentally relevant ecological risk assessment.
- Mechanism of toxicity of environmental pollutants
- Development of sensors and markers for detection of biological contaminants
- Remediation of hazardous and persistent chemical substances from soil and waste waters
- Ecotoxicity and environmental impact assessment
MIRNA profiling provides insights on adverse effects of Cr(VI) in the midgut tissues of Drosophila melanogaster
Cr(VI), a well-known environmental chemical, is reported to cause various adverse effects on exposed organisms including genomic instability and carcinogenesis. Despite available information on the underlying mechanism of Cr(VI) induced toxicity, studies regarding toxicity modulation by epigenetic mechanisms are limited. It was therefore, hypothesized that the global miRNA profiling in Cr(VI) exposed Drosophila, a genetically tractable model organism, will provide information about mis-regulated miRNAs along with their targeted genes and relevant processes. Third instar larvae of Drosophila melanogaster (Oregon R+) were exposed to 5.0-20.0 ?g/ml of Cr(VI) for 24 and 48 h. Following miRNA profile analysis on an Agilent platform, 28 of the 36 differentially expressed miRNAs were found to be significantly mis-regulated targeting major biological processes viz., DNA damage repair, oxidation-reduction processes, development and differentiation. Down-regulation of mus309 and mus312 under DNA repair, acon to oxidation-reduction and pyd to stress activated MAPK cascade respectively belonging to these gene ontology classes concurrent with up-regulation of dme-miR-314-3p, dme-miR-79-3p and dme-miR-12-5p confirm their functional involvement against Cr(VI) exposure. These findings assume significance since majority of the target genes in Drosophila have functional homologues in humans. The study further recommends Drosophila as a model to explore the role of miRNAs in xenobiotic induced toxicity. Chandra et al (2015) J Hazardous Materials 283:558-67.
Exposure to endosulfan influences sperm competition in Drosophila melanogaster
Dwindling male fertility due to xenobiotics is of global concern. Accordingly, male reproductive toxicity assessment of xenobiotics through semen quality analysis in exposed males, and examining progeny production of their mates is critical. These assays, in part, are biased towards monogamy. Females soliciting multiple male partners (polyandry) is the norm in many species. Polyandry incites sperm competition and allows females to bias sperm use. However, consequences of xenobiotic exposure to the sperm in the light of sperm competition remain to be understood. Therefore, we exposed Drosophila melanogaster males to endosulfan, and evaluated their progeny production as well as the ability of their sperm to counter rival control sperm in the storage organs of females sequentially mated to control/exposed males. Endosulfan (2?g/ml) had no significant effect on progeny production and on the expression of certain genes associated with reproduction. However, exposed males performed worse in sperm competition, both as 1st and 2nd male competitors. These findings indicate that simple non-competitive measures of reproductive ability may fail to demonstrate the harmful effects of low-level exposure to xenobiotics on reproduction and advocate consideration of sperm competition, as a parameter, in the reproductive toxicity assessment of xenobiotics to mimic situations prevailing in the nature. Misra et al (2014) Sci Rep 4: 7433.