ISOLATION OF NOVEL HUMAN AND MOUSE GENES OF THE RECA RAD51 RECOMBINATION-REPAIR GENE FAMILY/

Genes from the recA/RAD51 family play essential roles in homologous re combination in all organisms. Using sequence homologies from eukaryoti c members of this family we have identified fragments of two additiona l mammalian genes with homology to RAD51. Cloning the full-length cDNA s for both human and mouse genes showed that the sequences are highly conserved, and that the predicted proteins have characteristic feature s of this gene family. One of the novel genes (RS1H2)occurs in two for ms in human cDNA, differing extensively-at the 3' end, probably due to an unusual form of alternative splicing. The new genes (R51H2 and R51 H3) were mapped to human chromosomes 14q23-24 and 17q1.2, respectively . Expression studies showed that R51H2 is expressed at Tower levels th an R51H3, but that expression of both genes occurs at elevated levels in the testis compared with other tissues. The combination of gene str ucture conservation and the transcript expression patterns suggests th at these new members of the recA/RAD51 family may also function in hom ologous recombination-repair pathways.