Cloning and Characterization of a Candidate Gene for A-T Complementation Group D
Ataxia-telangiectasia (A-T) has been of interest to radiobiologists because A-T cells have two important responses to X-radiation: hypersensitivity to the killing effects of radiation (Taylor et al. 1975), and DNA synthesis that is not inhibited by exposure to ionizing radiation (i.e., radioresistant DNA synthesis) (Painter and Young, 1980). The exact defect in A-T cells is unknown; cloning of an A-T gene should lead to a new understanding of both human radiosensitivity and the regulation of DNA synthesis after radiation-induced DNA damage. One obvious method for cloning an A-T gene would be to introduce random normal human DNA segments into A-T cells in culture and then to screen these cells to find cell clones that had become at least partially radioresistant when compared with the original A-T cell line. This approach was begun in this Laboratory in 1983 and resulted in the isolation of a candidate A-T gene at the end of 1990. Currently, work is in progress to characterize this candidate gene and to determine whether it is the gene for A-T complementation group D.
KeywordsRadiation Hybrid Complementation Group IMR90 Cell Cosmid Clone Cosmid Library
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