Human chromosome 8 (p12-->q22) complements radiosensitivity in the severe combined immune deficiency (SCID) mouse

The severe combined immune deficiency (SCID) mouse shows two kinds of phenotypic abnormalities, a high radiosensitivity and an abnormal immunoglobulin gene recombination. A genetic study has revealed that a mutation exists in chromosome 16. However, several attempts to isolate the gene responsible for these phenotypes have been unsuccessful. By making use of the characteristics of radiosensitivity, we conducted complementation experiments to identify a human chromosome which contains the responsible gene. Radioresistant cells were selected from the hybrid cells of the SCID mouse and human fibroblasts. Based on this approach, the gene complementing the SCID phenotype was assigned to human chromosome 8 p12-->q22.