Chromosome painting analysis of radiation-induced aberrant cell clones in the mouse

Journal Article · Wed Oct 01 04:00:00 EDT 1997 · Environmental and Molecular Mutagenesis

OSTI ID:530865

Spruill, M D; Nath, J ^[1]; Tucker, J D ^[2]

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1. West Virginia Univ., Morgantown, WV (United States)
2. Lawrence Livermore National Lab., CA (United States)

In a study of the persistence of radiation-induced translocations over the life span of the mouse, we observed a number of clonal cells in peripheral blood lymphocytes. The presence of clones caused the mean frequency of aberrations at various time points to be elevated which interfered with biodosimetry. For this reason, we have corrected our data for the presence of clones. Mice were given an acute dose of 0, 1, 2, 3 or 4 Gy {sup 137}Cs at 8 weeks of age. Aberrations were measured by painting chromosomes 2 and 8 and cells were examined for clones at 3 months and every 3 months thereafter until 21 months. Clones were identified by comparing the color photographic slides of all abnormal cells from each animal. Determination of clonality was made on the basis of similar breakpoint locations or the presence of other identifying characteristics such as unusual aberrations. To correct the frequency of translocations for the presence of clones, each clone, regardless of how many cells it contained, was counted only once. This reflects the original aberration frequency since each clone originated as only one cell. Among mice exposed to 4 Gy, the mean frequencies of aberrant cell clones ranged from 3-29% of the total number of metaphase cells scored with the highest frequency being 1 year post exposure. 32-70% of reciprocal and 19-92% of non-reciprocal translocations were clonal. A dose response relationship for clones was evident until 21 months when the unexposed animals exhibited a mean frequency of aberrant cell clones >10% of the total number of cells scored. Almost 75% of reciprocal and 95% of non-reciprocal translocations in these unexposed control animals were of clonal origin. Correction for clonal expansion greatly reduced the means and their standard errors at most time points where clonal expansion was prevalent. The biodosimetry was much improved suggesting that correction is beneficial in long-term studies.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 530865
• Report Number(s): CONF-9704100--
• Journal Information: Environmental and Molecular Mutagenesis, Journal Name: Environmental and Molecular Mutagenesis Journal Issue: Suppl.28 Vol. 29; ISSN 0893-6692; ISSN EMMUEG
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL RADIATION EFFECTS
CHROMOSOMAL ABERRATIONS
MICE