EMBRYONIC LETHALITY AND RADIATION HYPERSENSITIVITY MEDIATED BY RAD51 IN MICE LACKING BRCA2

Inherited mutations in the human BRCA2 gene cause about half of the ca ses of early-onset breast cancer. The embryonic expression pattern of the mouse Brca2 gene is now defined and an interaction identified of t he Brca2 protein with the DNA-repair protein Rad51. Developmental arre st in Brca2-deficient embryos, their radiation sensitivity, and the as sociation of Brca2 with Rad51 indicate that Brca2 may be an essential cofactor in the Rad51-dependent DNA repair of double-strand breaks, th ereby explaining the tumour-suppressor function of Brca2.