Comparisons of genotype-tolerance responses in populations of Hediste diversicolor (Polychaeta: Nereididae) exposed to copper stress

Mitochondrial DNA and allozyme patterns of Hediste diversicolor (Polychaeta: Nereididae): the importance of small scale genetic structuring

“…Regardless of expectations of biological effects, we did not observe correlations between concentrations of heavy metals and estimators of genetic diversity in H. diversicolor based on both mitochondrial and allozyme markers. Furthermore, frequencies of the ALD 102/102 genotype were not correlated with Cu concentrations and hence did not support laboratory expectations about distributions of less tolerant ALD genotypes in the field (Virgilio et al 2005). Previous studies showed that populations of H. diversicolor from heavily contaminated sites in the UK had heritable tolerance to heavy metals, suggesting the occurrence of adaptive responses promoted by heavy metal stress (Bryan & Hummerstone 1971, Grant et al 1989).…”

“…5.3.1.9; Sorbitol dehydrogenase: SDH, E.C. 1.1.1.14) that in previous field surveys (Virgilio et al 2003) and laboratory experiments (Virgilio & Abbiati 2004a, Virgilio et al 2005 showed possible relationships with levels of heavy metal contamination. Cellulose acetate gel electrophoresis (CAGE) and staining were performed as described by Virgilio & Abbiati (2004b).…”

“…In particular, specimens with genotype ALD 102/102 showed shorter survival times under copper exposure. These results suggested that, in field populations of H. diversicolor, frequencies of genotype ALD 102/102 may be correlated to levels of copper contamination and that differences in genotype frequencies at ALD may be used as an indicator of copper stress (Virgilio et al 2005).…”

“…Spearman rank correlation coefficients were used to test correlations between concentrations of Cd, Cu, Ni, Pb and Zn (either in sediments or in tissues) and estimators of genetic diversity (h, π, H obs ). In order to verify whether ALD 102/102 genotype frequency may be used as a possible indicator of Cu stress in field populations of H. diversicolor (Virgilio et al 2005), correlations between ALD 102/102 frequencies and levels of Cu contamination (either in sediments or in tissues) were also tested.…”

“…Heavy metal stress promotes genotypic shifts in the allozyme patterns of laboratory populations of H. diversicolor (Virgilio & Abbiati 2004a). Previous experiments (Virgilio et al 2005) revealed that relationships between laboratory exposure to copper and genotype-tolerance responses at the enzyme locus Aldolase (ALD) were consistent both in space (i.e. among samples of H. diversicolor collected from sites thousands of kilometres apart) and in time (i.e.…”