Absolute Transcript Expression Signatures of Cyp and Gst Genes in Mus spretus to Detect Environmental Contamination

Abstract

We evaluated whether quantitation of mRNA molecules of key genes is a reliable biomonitoring end-point. We examined the Mus spretus expression levels of 19 transcripts encoding different cytochrome-P450s and glutathione transferases. Mice dwelling at the Doñana Biological Reserve were compared to those from an industrial settlement (PS). Metal biomonitoring indicated that PS animals sustained a heavier pollutant burden than those from the reference site. Transcript quantitations showed the following: (i) gender-related differences in the expression of most Cyp and Gst genes; (ii) one PS female displaying much smaller/larger transcript amounts than the remaining females; (iii) the concomitant up-regulation of Cyp1a2, Cyp2a5, Cyp2e1, Cyp4a10, Gsta1, Gsta2, Gstm1, and Gstm2 mRNAs in liver of PS males; and (iv) outstanding qualitative and quantitative differences between the hepatic expression signature of PS males and that promoted by paraquat. We conclude that (i) absolute amounts of transcripts encoding biotransformation enzymes are more potent biomarkers in males than in females, and in liver than in kidney; (ii) individual quantitations prevent biased interpretations by specimens with abnormal expression levels; and (iii)transcript expression signature of PS males is consistent with exposure to a complex profile of organic pollutants, other than oxidative stressors.

Global gene expression profiling using heterologous DNA microarrays to analyze alterations in the transcriptome of Mus spretus mice living in a heavily polluted environment

“…Several studies have justified the use of mice captured at the SOL for reference samples (Abril et al 2014;Abril et al 2011;Ruiz-Laguna et al 2006). The DRS flows through a highly industrialized area of SW Spain (Suppl.…”

“…1) as an indicator of mouse pollution burden. Following the rationale of previous studies (Abril et al 2014;MontesNieto et al 2007;Ruiz-Laguna et al 2006) and given the limited amounts of the individual livers, we used the kidney for metal determinations. Compared to SOL, four out of the eight analyzed elements (Fe, Zn, Cd, and Pb) were significantly more concentrated in the kidneys of DRS animals.…”

“…M. spretus has proven to be a useful sentinel species in monitoring programs through the use of different biometric, cytogenetic, and biochemical biomarkers (Bonilla-Valverde et al 2004;Marques et al 2006;Mateos et al 2008;Ruiz-Laguna et al 2006;RuizLaguna et al 2001;Viegas-Crespo et al 2003) and the use of global proteomic (Montes-Nieto et al 2007) and transcriptomic (Abril et al 2014;Abril et al 2011;RuizLaguna et al 2006) analyses. M. spretus diverged from the model mice M. musculus approximately 1.5 million years ago, but both species conserve a remarkable nucleotide sequence similarity (Abril et al 2014;Abril et al 2012;Mahler et al 2008;Ruiz-Laguna et al 2006). In a previous work, we have demonstrated the suitability of the commercial M. musculus oligonucleotide microarray for application in the sentinel species M. spretus (Abril et al 2014).…”

“…We have used an M. musculus whole genome oligonucleotide microarray and analyzed changes in the hepatic transcriptome of M. spretus mice captured in the zone where the DRS flows into the Huelva Estuary, at the confluence of the Odiel and Tinto Rivers. The rationale of this study rests on the relatively high gene sequence homology between the two mouse species, as shown in our own previous studies (Abril et al 2014;Abril et al 2012;Ruiz-Laguna et al 2006), and the need for effective biomarkers in environmental risk assessment.…”

Use of Metallomics and Metabolomics to Assess Metal Pollution in Doñana National Park (SW Spain)

“…8−12 Donãna National Park (DNP) is a 50 000 Ha wildlife reserve located in the Huelva province (SW Spain). Mus spretus mice attain a high population in DNP and has been used as a bioindicator in many studies 5,8,9,13,14 because of its ecological importance. 15 Yet, this area is threatened by adjacent agricultural, mining, and industrial activities that are responsible for the presence of metal species in its surroundings.…”