To address how individual genetic background affects tissue responses to low dose radiation in the intact organism. It is known that the molecular responses of cells exposed to biological stimuli or insults (such as radiation or chemicals) vary with the type of exposure, dose and dose rate of the insult and the type, genetic constitution, and tissue-organ site of the exposed cells.

To see if low dose radiation responses will differ among individuals because of genetic variation in the genes/proteins that cooperate in producing these responses.

This study will standardize conditions to validate specific gene responses to low dose radiation in different tissues from animals with different genotypes. Global molecular responses will be tested in these animals. Microarray technology will be used to measure radiation-induced changes in gene response in various tissues from genetically diverse inbred mouse strains and from mice with known mutations. Additionally, a mapping analysis of genetic segregation will be done to molecularly characterized variant strains of mice and determine reproducible variant low dose radiation responses.

Variant strains of mice with a range of genetic backgrounds will be molecularly characterizes so that they can be used to directly test the relevance of any specific radiation-induced molecular response on phenotypes. Studies will be conducted to determine how these responses can be altered by genetic or environmental factors.