Genetic indicators of environmental stress in central mudminnow (Umbra Limi) populations exposed to acid deposition in the Adirondack Mountains

Abstract

Horizontal starch gel electrophoresis was used to characterize the genetic structure of central mudminnow (Umbra limi) populations from acid stressed (low pH/high Al) and nonacid‐stressed sites in the north branch of the Moose River (NBMR), New York, in order to determine if environmental shifts were accompanied by detectable shifts in genetic structure Central mudminnow populations in the NBMR were characterized by significantly (p ≥ 0 05) lower heterozygosity levels at stressed sites (H (mean number of heterozygotes per locus per individual) = 0 060 0 102) than reference sites (H = 0 130, 0 142) Additionally, several genetic loci demonstrated either consistent (isocitrate dehydrogenase, phosphogluconate dehydrogenase) or moderately consistent (glucose 6 phosphate isomerase 1 malate dehydrogenase‐1, mannose‐6 phosphate isomerase) genotypic shifts in comparisons between populations at reference and low pH/high Al sites Populations at acid stressed sites were characterized by higher frequencies of one particular allozyme, suggesting that environmental conditions were acting as a selective force In acute laboratory toxicity tests (pH, 4 5, Al, 7 5 mg/L), the most tolerant fish were significantly more genetically variable, indicating that genetic diversity may be beneficial to the survival of individual fish experiencing physiological stress

Genetics of radionuclide‐contaminated mosquitofish populations and homology betweenGambusia affinisandG. holbrooki

“…However, in neither species was the genetic diversity lower in the contaminated populations than in the reference populations. This is not in concordance with other studies [5–10], for which this was the case. This could be due to the fact that past studies examined mitochondrial DNA and allozyme loci, whereas the present study used RAPD loci.…”

“…This, in turn, could result in alteration in genetic variability or allele frequencies [1,2]. Many examples of these phenomena are available in the literature, implicating both genetic bottlenecks [5–10] and pollution‐mediated natural selection [11–17] as effectors of population genetic change. The overall trends revealed by these investigations were that populations from polluted habitats exhibited less genetic variability than those from reference areas and/or that in terms of genotype frequencies, the reference populations were more similar to each other than to the polluted populations, and in many cases these patterns could not be explained solely on the basis of gene flow.…”

Use of Molecular Markers to Study the Effects of Environmental Impacts on Genetic Diversity in Brown Bullhead (Ameirus Nebulosus) Populations

“…Many other PAHs were present in OWC sediments at concentrations two to three times greater than in sediments from Buckeye Lake. Anthropogenic stressors can affect genetic structuring and the dynamics of populations [12,13,15,16,18,19,49, and reviewed in 50]. Field data [48] and laboratory studies [47] suggest a causal relationship between the observed neoplasia and contaminated river sediments, especially PAHs.…”

“…sponse to a variety of pollutant exposures (e.g., heavy metals on perch [12], shrimp [13], and plants [14]; coal ash on mosquitofish and snails [15]; acid deposition on mudminnows [16]; temperature on mummichogs [17]; and radionuclide exposure on mosquitofish [18,19]). These studies indicate that exposure to pollutants results in selection against sensitive phenotypes, leading to a reduction in the overall genetic diversity of the affected population.…”

Evolutionary Toxicology: Population-Level Effects of Chronic Contaminant Exposure on the Marsh Frogs ( Rana ridibunda ) of Azerbaijan

“…Haplotype, as used throughout this article, is defined as a unique sequence of nucleotides for a defined region, providing a distinctive genetic pattern. The loss of population genetic diversity has been linked to environmental contaminants (Kopp et al 1992; Krane et al 1999; Murdoch and Hebert 1994; Street and Montagna 1996). …”