Genetic mapping of two pairs of linked ribosomal protein genes in Saccharomyces cerevisiae.

We have used the 2 mu mapping method described by Falco and Botstein (1983) and tetrad analysis to map four ribosomal protein genes (two linked pairs) in S. cerevisiae. One pair (rp28-rp55 copy 1) is on chromosome XV, 14 cM proximal to ARG8. The other pair (rp55-rp28 copy 2) is 19 cM from the centromere on the left arm of chromosome XIV. To map copy 1 we used the E. coli beta-galactosidase gene rather than a yeast gene to mark the ribosomal protein chromosomal locus. This provided a more sensitive color screening assay for chromosome loss in the 2 mu method. It also removed the restriction that the mapping tester strains must be mutant for the plasmid marker.