Differential gene expression analysis in eisenia fetida chronically exposed to benzo[a]pyrene

Benzo(a)pyrene (BaP) is a well-established carcinogen and mutagen that belongs to polycyclic aromatic hydrocarbons (PAHs) group of chemicals. BaP and other PAHs are derived as a result of incomplete combustion of fossil fuel and organic materials (Yunker et al., 2002). BaP reaches the environment from domestic emissions and wastes, automobile exhausts, industrial emission, agricultural activities and also by some natural sources (Ravindra et al., 2008). BaP has been found to accumulate in several organisms such as (Subashchandrabose et al., 2014), mussels (Canova et al., 1998) and mouse (Uno et al., 2006). BaP is known to be mutagenic in somatic cells. Analysing global transcription effect in an organism might reveal potential toxic effect as well as the toxicological mechanisms (Huang et al., 2014). Since soil is the largest sink for BaP it is essential to use terrestrial organism such as the Eisenia fetida (earthworm), to develop molecular biomarkers by studying the differential gene expression in response to BaP. Alteration in gene expression profile would be a powerful tool to diagnose the effects of a toxic pollutant such as BaP at very low levels. Next generation mRNA sequencing is one of the tools available these days to analyse such changes in gene expression profiles. E. fetida was chronically exposed to 10 mg/kg of BaP for about eight months and the gene expression profile was studied. (author)