Although no statistically significant hereditary effects have yet been detected in the children of survivors from the atomic bombings in Hiroshima and Nagasaki, recent animal studies have found that exposure to ionizing radiation can cause genomic and epigenomic instability in the exposed individuals, as well as their offspring, and therefore, may have much larger genetic effects than predicted by earlier studies. When individuals are exposed to various environmental insults, including radiation, individual sensitivity to the insults often varies. Variance in germ-line response to radiation among individuals has been widely recognized, but it is difficult to address due to the use of inbred strains and the limited number of offspring that can be produced by a pair of mice, the common model used to study genetic effects of radiation. Herein is the first study to examine individual family responses to ionizing radiation using a parent-pedigree approach in an outbred strain of a vertebrate model, the Japanese medaka fish. Changes in frequencies of radiation-induced germline mutations at nine microsatellite loci were examined in the same families before and after exposure to one of four acute doses of ionizing radiation (0.1, 0.5, 2.5, 5. Gy, plus sham-exposed controls). Families varied significantly in pre-exposure mutation frequencies and responses to irradiation, but germline mutations were elevated in at least one family after 0.1, 0.5, and 5. Gy exposures. Variance among individuals in sensitivity to radiation is well documented for many endpoints, and our work now extends these endpoints to include germ-line mutations. Further studies are needed to elucidate dose response, effects at varying stages of spermatogenesis, and the mechanisms underlying the variance in these individual responses to radiation.
|Number of pages||6|
|Journal||Mutation Research - Genetic Toxicology and Environmental Mutagenesis|
|State||Published - Jan 11 2011|
Bibliographical noteFunding Information:
We thank Maureen Peters, Tracey Tuberville and Elizabeth Burgess for assisting with DNA extractions and Fred Ogden and Cecilia Watson for help with the radiation exposure. The work was supported by U.S. Department of Energy (DOE) Grant No. DE-FG02-05ER64087 to Colorado State University and the University of Georgia Research Foundation and DE-FC09-07SR22506 which supported the University of Georgia's Savannah River Ecology Laboratory.
- Germline mutations
- Individual response
ASJC Scopus subject areas
- Health, Toxicology and Mutagenesis