Expression of metallothionein genes I and II in bank vole Clethrionomys glareolus populations chronically exposed in situ to heavy metals.
The expression of two metallothionein genes (Mt-I and Mt-II) in the liver, kidney, and gonad of bank voles collected at four metal-contaminated sites (Cd, Zn, Pb, and Fe) were measured using the quantitative real-time PCR method (QPCR). Relative Mt gene expression was calculated by applying a normalization factor (NF) using the expression of two housekeeping genes, ribosomal 18S and beta-actin. Relative Mt expression in tissues of animals from contaminated sites was up to 54.8-fold higher than those from the reference site for Mt-I and up to 91.6-fold higher for Mt-II. Mt-II gene expression in the livers of bank voles from contaminated sites was higher than Mt-I gene expression. Inversely, Mt-II expression in the kidneys of voles was lower than Mt-I expression. Positive correlations between cadmium levels in the tissues and Mt-I were obtained in all studied tissues. Zinc, which undergoes homeostatic regulation, correlated positively with both Mt-I and Mt-II gene expression only in the kidney. Results showed that animals living in chronically contaminated environments intensively activate detoxifying mechanisms such as metallothionein expression. This is the first time that QPCR techniques to measure MT gene expression have been applied to assess the impact of environmental metal pollution on field collected bank voles.
Swiergosz-Kowalewska
Renata
R
Institute of Environmental Sciences, Department of Ecotoxicology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. uxswierg@cyf-kr.edu.pl
Bednarska
Agnieszka
A
Callaghan
Amanda
A
D000818:Animals; D003411:Arvicolinae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D007668:Kidney / Q000187:drug effects* / Q000473:pathology; D008668:Metallothionein / Q000235:genetics*; D019216:Metals, Heavy / Q000633:toxicity*; D016133:Polymerase Chain Reaction / Q000379:methods; D011157:Population Dynamics; D013997:Time Factors; D015032:Zinc / Q000633:toxicity
D004785:Environmental Pollutants; D019216:Metals, Heavy; D002104:Cadmium; D008668:Metallothionein; D015032:Zinc