Grantee Research Project Results
2000 Progress Report: Intraspecies genetic diversity measures of environmental impacts.
EPA Grant Number: R826599Title: Intraspecies genetic diversity measures of environmental impacts.
Investigators: Krane, Daniel , Grasman, Keith A. , Burton, Jr., G. Allen
Institution: Wright State University - Main Campus
EPA Project Officer: Hahn, Intaek
Project Period: August 1, 1998 through July 31, 2002
Project Period Covered by this Report: August 1, 1999 through July 31, 2000
Project Amount: $420,278
RFA: Ecological Indicators (1998) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Aquatic Ecosystems
Objective:
The objectives of this project are to: (1) determine the suitability of RAPD-PCR (randomly amplified polymorphic DNA-polymerase chain reaction) based measures of genetic diversity as an alternative to or screening test for U.S. EPA acute and chronic toxicity and bioaccumulation tests of ecological risk in a wide variety of resource types; and (2) assess the amenability of a set of organisms from a range of trophic levels to genetic diversity-based measures that sensitively, rapidly, and inexpensively assay the impact of a broad range of environmental stressors.
Progress Summary:
The initial stages of this work have focused on refining the RAPD-PCR DNA profiling technique and determining which native organisms at a variety of local aquatic and terrestrial sites would be most suitable for analyses. As reported previously, profiles from a total of five different aquatic species [(crayfish, snails, fathead minnows (Pimephales promelas) and mosquitofish (Gambusia affinis), damsel fly and Hyalella azteca)] and five terrestrial species (pill bugs, earth worms, spiders, garlic mustard and violets) have been generated and evaluated. Limited genetic diversity in garlic mustard and difficulties in typing violets to the species level when not flowering have prompted their replacement as possibly useful ecoindicators with a commonly found, invasive plant: purple loose-strife. Pacific herring also have been profiled in an effort to expand the study to salt water systems as described in the original proposal. All organisms studied to date have proven amenable to highly reproducible RAPD-PCR typing.
The important roles played by the species considered to date?in addition to their non-migratory natures, normally high population densities, broad distribution, and sexual reproduction?make them very well-suited for genetic diversity studies. With the exception of garlic mustard and violets as noted above, all organisms studied to date display statistically significant differences in genetic diversity between populations collected at contaminated and reference sites. In general, populations collected at reference sites have had the highest levels of diversity and these measures are correlated with the diversity measures of other species collected at the same sites as well as with other measures of ecosystem health including IBI (the Index of Biotic Integrity) and ICI (the Invertebrate Community Index). Notable exceptions to that trend however, include pill bugs and damsel fly where environmental disruption by anthropogenic stressors may provide more opportunities for unrelated, immigrant individuals and/or refuge from predators.
RAPD-PCR profiling of the organisms described above is now close to completion. Completion of genetic diversity calculations is currently underway. Statistical analyses of genetic diversity values and the individual metrics of IBI and ICI are beginning to show that some environmental features play a greater role than others in influencing the genetic diversity of sentinel species.
Future Activities:
Initial surveys of aquatic systems and their closely associated terrestrial sites have been made upon Dick's Creek in Middletown, OH, and the Little Scioto River in Marion, OH. Scoring of DNA profiles and determination of genetic diversity levels will be completed and statistical comparisons of diversity levels and IBI and ICI component metrics will be performed.
Genetic diversity levels of the most informative sentinel species observed to this point in the study, Hyalella azteca, will be considered in surveys of a third aquatic system that has been contaminated with a different set of pollutants. Specifically, organisms have been collected at one reference and three contaminated sites along the Clark Fork River in southwest Montana. This river transects a variety of agricultural areas along its 120 mile reach. Mining, milling and smelting activities have occurred extensively throughout its headwater and tributary streams resulting in substantial heavy metal contamination of the watershed. The system is particularly interesting due to its harboring of a pollution sensitive and high quality benthic macroinvertebrate community despite extreme metal toxicity levels. Cage experiments with Hyalella azteca also are underway to determine if genetic diversity levels in commercially available stocks of this organism are comparable to those found in nature and if differences in diversity levels actually alter their susceptibility to stressors when they are used in controlled field studies.
For terrestrial systems, collections of pill bugs have been obtained from a series of 10 paired sites (one actively remediated and one simply abandoned) at which strip mining has occurred. Each pair of sites differs from the others in terms of the time since mining activity has ended. RAPD-PCR profiles of those populations currently are underway.
Journal Articles:
No journal articles submitted with this report: View all 35 publications for this projectSupplemental Keywords:
population, genetic polymorphisms, ecological effects, indicators, terrestrial, aquatic, biology, surveys., RFA, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, exploratory research environmental biology, Ecosystem Protection, Chemical Mixtures - Environmental Exposure & Risk, State, Ecological Effects - Environmental Exposure & Risk, Monitoring/Modeling, Ecological Effects - Human Health, Ecological Indicators, ecological exposure, risk assessment, anthropogenic stresses, stressors, biodiversity, stream ecosystems, molecular detection, biotic integrity, ecosystem indicators, terrestrial, Ohio (OH), DNA, RAPD-PCR, water quality, snailsRelevant Websites:
http://Biology.wright.edu/BioSite/personnel/faculty/Krane.html
http://Biology.wright.edu/BioSite/personnel/faculty/Burton.html
http://Biology.wright.edu/BioSite/personnel/faculty/Grasman.html
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.