Genetic ecotoxicology of radionuclides in mosquitofish: The relationship between DNA strand breaks and genotype

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:211966

Theodorakis, C W; Shugart, L R ^[1]

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1. Oak Ridge National Lab., TN (United States)

DNA polymorphisms revealed by RAPD (Randomly Amplified Polymorphic DNA) and allozyme analysis were compared to relative amounts of DNA strand breakage, determined by gel electrophoresis, in mosquitofish (Gambusia affinis). The fish examined were from three different experiments, as follows : (1) fish collected from a radioactively contaminated pond; (2) fish collected from a non-radioactively contaminated pond and exposed to X-rays in the laboratory; and (3) fish collected from a non-radioactively contaminated pond and caged in a radioactive or non-radioactive pond. The types of RAPD metrics used were number of bands per individual and frequency of certain bands. It was found in a previous study that in some instances the number of bands and the frequency of certain bands in the population were elevated in radionuclide-contaminated sites relative to reference sites. In several cases, the median molecular length (MML) of the DNA (which is inversely proportional to the amount of strand breakage) was correlated to the number of bands per individual. Also, for bands which had a higher population frequency in contaminated sites, the MML in many cases was higher for fish with than without these bands. Results from laboratory X-ray exposures paralleled those from the field. In the caging study, 9 out of the original 30 caged fish survived in the radioactive pond, whereas 27 fish survived in the non-radioactive cage. In the radioactive cage the genotypic distribution of the survivors was more similar to the indigenous radioactive population than to the population of origin. When the relative amount of DNA strand breakage was compared to the genotype of each survivor, the patterns were similar to those found in the field collection and laboratory studies.

• OSTI ID: 211966
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BENCH-SCALE EXPERIMENTS
FIELD TESTS
FISHES
GENETIC RADIATION EFFECTS
PONDS
RADIOINDUCTION
STRAND BREAKS
X RADIATION