Transcriptomes analysis of Aeromonas molluscorum Av27 cells exposed to tributyltin (TBT): Unravelling the effects from the molecular level to the organism

Andreia Cruz,Raquel Rodrigues,Miguel Pinheiro,Sónia Mendo

doi:10.1016/j.marenvres.2015.06.017

Andreia Cruz, Raquel Rodrigues + Show 2 more

Open Access

https://doi.org/10.1016/j.marenvres.2015.06.017

Copy DOI

Abstract

Aeromonas molluscorum Av27 cells were exposed to 0, 5 and 50 μM of TBT and the respective transcriptomes were obtained by pyrosequencing. Gene Ontology revealed that exposure to 5 μM TBT results in a higher number of repressed genes in contrast with 50 μM of TBT, where the number of over-expressed genes is greater. At both TBT concentrations, higher variations in gene expression were found in the functional categories associated with enzymatic activities, transport/binding and oxidation-reduction. A number of proteins are affected by TBT, such as the acriflavin resistance protein, several transcription-related proteins, several Hsps, ABC transporters, CorA and ZntB and other outer membrane efflux proteins, all of these involved in cellular metabolic processes, important to maintain overall cell viability.Using the STRING tool, several proteins with unknown function were related with others involved in degradation processes, such as the pyoverdine chromophore biosynthetic protein, that has been described as playing a role in the Sn–C cleavage of organotins.This approach has allowed a better understanding of the molecular effects of exposure of bacterial cells to TBT. Furthermore it contributes to the knowledge of the functional genomic aspects of bacteria exposed to this pollutant. Furthermore, the transcriptomic data gathered, and now publically available, constitute a valuable resource for comparative genome analysis.

Highlights

Tributyltin (TBT) is a hydrophobic organic derivative of tin (Antizar-Ladislao, 2008), that possesses broad-spectrum biocidal properties
106,896 reads were obtained in the control library, which assembled into 1360 contigs. 60,378 reads were obtained in the library corresponding to the cells exposed to 5 mM TBT which were assembled into 1147 contigs
In the library corresponding to the cells exposed to 50 mM TBT, 80,276 reads were obtained, which were assembled into 1325 contigs (See Table S2, Supporting Information)

Summary

Introduction

Tributyltin (TBT) is a hydrophobic organic derivative of tin (Antizar-Ladislao, 2008), that possesses broad-spectrum biocidal properties. It has several applications, such as the production of PVC, agrochemicals, glass, textile, etc. In 2003, the European Union prohibited its usage on ships, and later, in 2008, TBT was banned by the International Maritime Organization (Antizar-Ladislao, 2008). Considering that it is a persistent organic pollutant, TBT is still causing several environmental problems (Chapman and Guillette, 2013) and negative effects in both prokaryotes and eukaryotes (Cooney and Wuertz, 1989a). Due to its role as an endocrine disruptor, TBT has been considered a xenobiotic obesogen (Grun et al, 2006)

Methods

Results

Conclusion