Analysis of transgenerational effects on DNA copy number aberrations in male mice exposed to continuous 20mGy/day gamma-rays for 400 days (Primary screening for 0mGyE family)

Transgenerational effects of continuous low dose-rate (LDR) gamma-ray irradiation have not been well studied. Recent advances in DNA technology enabled us to examine a whole genome at molecular level. Here we adopted one of these techniques called oligo-microarray comparative genome hybridization (CGH) and studied trans-generational effects on DNA copy number aberrations (CNAs). C57BL/6JNrs male mice were exposed to LDR gamma-rays (20 mGy/day) for 400 days (total dose: 8000 mGy) from 8 weeks of age. Progeny from 20 mGy/day irradiated mice had significantly higher frequencies of genomic aberrations than the progeny of non-irradiated mice. This study investigated the De novo mutation by comparing the parents and children using 25 irradiated male family and 25 non irradiated male family. This study was performed under contract with the Aomori Prefectural Government, Japan. We irradiated and non irradiated male mice (C57BL/6JNrs) for 400 days and cross to non irradiated female mice (C57BL/6JNrs) and got F1 mice. After they dead the DNA were prepared from their tails. At first, primary screening using １M oligo-microarray was performed. The array was mounted autosomal fragment at intervals of an average about 3kb. Two-condition experiment, mice tail tissue irradiated or non-irradiated male, female and their progenies vs. reference male mouse. This reference male mouse was from the same colony used in this experiment. Twice by changing the labeling color Cy3 and Cy5, performed CGH and extracting probes showed either aberration. Identification the chromosomal location of the probe. Probes adjacent to the probe with aberration were set at high density. The candidate probes in one family was designed in a single 4x 244k or 8x 60k oligo-microarray and performed secondary screening. Extracting the flanking probes showed either aberration when labeled with Cy3 and Cy5 and identification the chromosomal location of the probe. Finally, we performed TaqMan® Copy Number Assays to verify the mutations. This SubSeries is a primary screening. non-irradiated male (0mGyEM), female (0mGyEF) and their progenies (0mGyE1 to 0mGyE6) vs. reference male mouse 1.