Biochemical analysis of allozyme copper and cadmium tolerance in fish using starch gel electrophoresis

Abstract

The in vitro effects of copper and cadmium on fish enzyme activity were assayed by combining the metals with the biochemical stains used to resolve these enzyme systems on starch gels. The effects of copper and cadmium on the activity of PGM‐2, GPI‐2 and IDH‐2 enzymes in mosquitofish were assayed using stain‐metal mixtures containing 2.0 ml 0.1 m CuSO4 · 5H2O or 0.1 m CdSO4. Enzymes whose activities were effected by copper in this initial test were resolved using a series of stain‐metal mixtures containing copper at lower concentrations to determine effect threshold concentration ranges and to determine concentration ranges that might produce differential effects on activity among allozymes of a single protein. Interspecific differences in the effect of copper on the activity of PGM‐2 enzyme variants were examined for 17 fish species from seven locations. Copper was found to effect the activity of PGM‐2, GPI‐2, and IDH‐2 enzymes in mosquitofish and intraspecific and interspecific differences existed in the copper sensitivity of enzymes in a number of the fish species tested. Allozyme phenotypes at the PGM‐2 locus in mosquitofish observed on test gels (0.9 mg Cu/L) suggests that two isoalleles, one copper‐tolerant and one copper‐sensitive, are present at this locus.

Effects of metal contamination from mine tailings on allozyme distributions of populations of great plains fishes

“…Other metal ions, particularly zinc, may compete with the required metallic cofactor for binding sites, reducing or inhibiting enzyme activity [1]. For example, Chagnon and Guttman [18] demonstrated that the activities of Gpi-2, Pgm-2, and Icd-2 (enzymes that require magnesium ions) were affected by the presence of copper in electrophoretic stain mixtures, and that sensitive and tolerant allozyme genotypes occurred for Pgm-2.…”

“…Experimental in vitro procedures, following techniques first developed by Chagnon and Guttman [18], were used to assess possible effects of zinc and lead on enzymatic products of the polymorphic loci assayed for the field collections. The purpose of this experiment was twofold.…”

Population genetic structure and tolerance to dioxin-like compounds of a migratory marine fish (Menidia menidia) at polychlorinated biphenyl–contaminated and reference sites

“…This seems to be a plausible explanation for metal contamination, because inhibition of PGM activity has been observed in the presence of metals [27,28], but we are aware of no similar evidence for nonmetal contaminants. The activity of PGM allozymes may be differentially affected by the presence of contaminants.…”

“…The activity of PGM allozymes may be differentially affected by the presence of contaminants. This seems to be a plausible explanation for metal contamination, because inhibition of PGM activity has been observed in the presence of metals [27,28], but we are aware of no similar evidence for nonmetal contaminants.…”

Mercury contamination and population-level responses in chironomids: Can allozyme polymorphism indicate exposure?

“…Nevo and coworkers [3][4][5][6][7][8][9][10] found differential survivorship among allozyme genotypes for several marine species between contaminated and reference conditions in both laboratory and field situations. Guttman and coworkers [11][12][13] also found correlations for several enzyme-determining loci with toxicant exposure. Studies by Mitton and Koehn [14] on mummichog minnows (Fundulus heteroclitus) and Smith et al [15] on largemouth bass (Micropterus salmoides) found that allozyme frequencies differed significantly between populations inhabiting artificially heated waters relative to those of unheated waters.…”