Development of a recombinant DNA assay system for the detection of genetic change in astronauts' cells
We are developing a new recombinant DNA system for the detection and measurement of genetic change in humans caused by exposure to low level ionizing radiation. A unique feature of the method is the use of cloned repetitive DNA probes to assay human DNA for structural changes during or after irradiation. Repetitive sequences exist in different families. Collectively they constitute over 25% of the DNA in a human cell. Repeat families have between 10 and 500,000 members. We have constructed repetitive DNA sequence libraries using recombinant DNA techniques. From these libraries we have isolated and characterized individual repeats comprising 75 to 90% of the mass of human repetitive DNA. Repeats used in our assay system exist in tandem arrays in the genome. Perturbation of these sequences in a cell, followed by detection with a repeat probe, produces a new, multimeric ''ladder'' pattern on an autoradiogram. The repeat probe used in our initial study is complementary to 1% of human DNA. Therefore, the sensitivity of this method is several orders of magnitude better than existing assays. Preliminary evidence from human skin cells exposed to acute, low-dose x-ray treatments indicates that DNA is affected at a dose as low as 5R. The radiation doses used in this system are well within the range of doses received by astronauts during spaceflight missions. Due to its small material requirements, this technique could easily be adapted for use in space. 16 refs., 1 fig.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 5826109
- Report Number(s):
- LA-UR-85-823; CONF-8410230-12; ON: DE85010103
- Resource Relation:
- Conference: Lunar bases and space activities of the 21st century, Washington, DC, USA, 29 Oct 1984; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DNA
GENETIC RADIATION EFFECTS
LOW DOSE IRRADIATION
MUTAGEN SCREENING
AUTORADIOGRAPHY
BIOASSAY
CLONING
MAN
RECOMBINANT DNA
SKIN
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
GENETIC EFFECTS
IRRADIATION
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PRIMATES
RADIATION EFFECTS
SCREENING
VERTEBRATES
560111* - Radiation Effects on Biochemicals- In Vitro- (-1987)