Frequencies of chromosomal aberrations and sister chromatid exchanges in the benthic worm Neanthes arenaceodentata exposed to ionizing radiation

Technical Report · Sun Jul 01 04:00:00 EDT 1984

DOI:https://doi.org/10.2172/6440856· OSTI ID:6440856

Harrison, F L

Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. The SCEs, in contrast to chromosomal aberrations, do not alter the overall chromosome morphology and in mammalian cells appear to be a more sensitive indicator of DNA alterations caused by environmental mutagens. Newly hatched larvae were exposed to two radiation-exposure regimes of either x rays at a high dose rate of 0.7 Gy (70 rad)/min for as long as 5.5 min or to /sup 60/Co gamma rays at a low dose rate of from 4.8 x 10/sup -5/ to 1.2 x 10/sup -1/ Gy (0.0048 to 12 rad)/h for 24 h. After irradiation, the larvae were exposed to 3 x 10/sup -5/M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h (/sup 60/Co-irradiated larvae). Larval cells were examined for the proportion of cells in first, second, and third or greater division. Frequencies of chromosomal aberrations and SCEs were determined in first and second division cells, respectively. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but a dose of equal or greater 2 Gy (equal to or greater than 200 rad) was required to observe a significant increase. Worm larvae receiving /sup 60/Co irradiation showed elevated SCE frequencies with a significant increase of 0.6 Gy (60 rad). We suggest that both SCEs and chromosomal aberrations may be useful for measuring effects on genetic material induced by radiation. 56 references, 7 figures, 9 tables.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6440856
• Report Number(s): UCRL-53524; ON: DE85003159
• Country of Publication: United States
• Language: English

Related Subjects

560153* -- Radiation Effects on Animals-- Invertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
ANNELIDS
AQUATIC ORGANISMS
BIOLOGICAL EFFECTS
BIOLOGICAL INDICATORS
BIOLOGICAL RADIATION EFFECTS
CHROMOSOMAL ABERRATIONS
DATA
DOSE-RESPONSE RELATIONSHIPS
EXPERIMENTAL DATA
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
INFORMATION
INVERTEBRATES
IRRADIATION
LARVAE
LOW DOSE IRRADIATION
MANAGEMENT
MARINE DISPOSAL
MATERIALS
MUTATIONS
NUMERICAL DATA
RADIATION EFFECTS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
SISTER CHROMATID EXCHANGES
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES