A GENETIC-ANALYSIS OF THE 63E-64A GENOMIC REGION OF DROSOPHILA-MELANOGASTER - IDENTIFICATION OF MUTATIONS IN A REPLICATION FACTOR-C SUBUNIT

We have performed an F-2 genetic screen to identify lethal mutations w ithin the 63E-64A genomic region. We have isolated 122 mutations in 20 different complementation groups. Of these groups, 16 are represented by multiple alleles. We have also established that the Rop and Ras2 g enes are located within the 63E-64A genomic domain at 64A10,11. We hav e sequenced 10.2 kb of DNA surrounding this gene pair and find chat in addition to Rop and Ras2 there is another gene located within this DN A sequence. The gene product, which we have named Rfc40, shows 68% ide ntity to the 40-kDa subunit of replication factor C. We find that the members of one complementation group (13 alleles) derived from our scr een correspond to mutations in the Rop gene, whereas the members of an other (five alleles) correspond to mutations in the Rfc40 gene. In add ition we have isolated 11 new mutant alleles of the disembodied gene.