Genetic Indicators Research Molecular Ecology Research Branch NERL Overview- Genetic diversity...

Genetic Indicators Genetic Indicators Research Research Molecular Ecology Molecular Ecology

Research BranchResearch Branch

NERLNERL

Overview- • Genetic diversity within species• Gene induction (expression)

research• Some considerations for

transplanting genetically resistant organisms

Research GoalsResearch Goals

GPRA-• Goal 8.1.1 - By 2008, develop indicators

and monitoring designs for a national stream and coastal survey.

• FY00 APM - A draft report on the feasibility of genetic and molecular biomarkers as an indirect measure of pesticide, toxics, and metals exposure to fish in the Eastern Cornbelt Plains ecoregion.

Genetic Diversity IndicatorGenetic Diversity Indicator

• Indicator of population sustainability


• Indicator of population sustainability– The ability of an organism to

adapt to changing environmental conditions is dependent on genetic variation


• Indicator of population sustainability– The ability of an organism to adapt to

changing environmental conditions is dependent on genetic variation

– For small, threatened populations, inbreeding increases the probability of extinction


• Indicator of population integrity


• Indicator of population integrity– Forces that influence genetic

diversity (selection, mutation, migration, drift) do so through their effects on populations•Dispersal•Population size•Reproductive success


• Indicator of population integrity– Forces that influence genetic diversity

(selection, mutation, migration, drift) do so through their effects on populations

– Can estimate key population parameters with genetic information•Effective population size•Effective migration rates


• Indicator of population integrity– Forces that influence genetic

diversity (selection, mutation, migration, drift) do so through their effects on populations

– Cumulative indicator of condition

HCV HS SM TD PLPLO MS Z B K

1 21 2

DNA Fingerprints


Major Products-• Regional genetic diversity profile

for populations of the central stoneroller in the Eastern Cornbelt Plains Ecoregion– Report by end of the year


Major Products-• Regional genetic diversity profile for

populations of the central stoneroller in the Eastern Cornbelt Plains Ecoregion

• Regional multi-species genetic diversity profile for mid-eastern US.– Report for stonerollers by end of next year

ECBP and MAIA Sampling sites


Other Projects-• Genetic diversity profile for creek

chubs in the coal-bearing regions of WV, VI


Other Projects-• Genetic diversity profile for creek

chubs in the coal-bearing regions of WV, VI

• Genetic structure of mummichog populations adapted to high concentrations of PAHs.– Collaboration with NHEERL- Narragansett

Gene Expression IndictorGene Expression Indictor

• Diagnostic indicators of exposure

Control of Gene Expression

DNA1

transcriptionalcontrol

2RNA

processingcontrol

primaryRNA

transcript mRNA mRNA

NUCLEUS CYTOSOL

4

proteinactivitycontrol

3

translationcontrol

protein inactiveprotein

nuclear pore

nuclear envelope

Gene Expression IndicatorGene Expression Indicator

• Diagnostic indicators of exposure– Detect ‘first cellular event’

following exposure



following exposure– Highly sensitive to even trace

materials



following exposure– Highly sensitive to even trace

materials– Highly diagnostic of exposure to

specific classes of stressors

Molecular methods have Molecular methods have been developed to detect been developed to detect

changes in:changes in:• Vitellogenin gene expression

– Exposure to estrogenic compounds

• Cytochrome P450IA1 gene expression– Exposure to PAHs

• Metallothionein gene expression– Exposure to metals

Major ProductsMajor Products

• Estrogenic compound indicator– Method in place for rainbow trout,

fathead minnow• PAH indicator

– Method under development through cooperative agreement

• Metals indicator– Method in place for rainbow trout

Estrogenic Activity Estrogenic Activity indicatorindicator

con

trol 0

.01

0

.10 0

.33 0

.33 0

.33

Vitellogenin

18S rRNA

Some considerations Some considerations regarding transplantation regarding transplantation of adapted organisms and of adapted organisms and

communitiescommunities

Transplantation IssuesTransplantation Issues

1. Is the population really adapted to mining impact area?

• Adaptation or acclimation?• Bioavailability differences

between sites?• Adapted to same or different

stressor profiles?


2. Will the mitigation create new problems?

• Will the transplants interbreed with nearby locally adapted populations?

• Will the population need constant supplementation?

• Will an artificial selection program need to be created?


3. Research need: an ability to predict population responses to stressors: acclimation, adaptation, or extinctionDepends on:• Magnitude and novelty of stressor• Number of genes involved in response• Genetic diversity of response genes• Rate of environmental change

Possible contributions by EPA genetics researchers

• Assessment of bioavailability differences between sites

– Metallothionein gene expression• Assessment of population structure/

gene flow within region– Most appropriate transplant populations– Potential for introgression with native

stocks– Monitoring of population status

Genetic Indicators Research Molecular Ecology Research Branch NERL Overview- Genetic diversity...

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