IDENTIFICATION OF NEW CHROMOSOMES OF SACCHAROMYCES-BAYANUS USING GENEPROBES FROM SACCHAROMYCES-CEREVISIAE

The Saccharomyces cerevisiae genes HIS3 (chr. XV), LYS2 (chr. II), ARG 4 (chr. VIII), MFalpha1 (chr. XVI) and MEL1 (chr. II) and the S. pasto rianus gene MELx were used for identification of the homeologous chrom osomes in S. bayanus by using pulsed-field gel electrophoresis and Sou thern blot hybridization. The results showed differences in hybridizat ion intensities and mobilities between the homeologous chromosomes of the two sibling yeasts S. cerevisiae and S. bayanus. The probes HIS3, LYS2, MEL1, and MFalpha1 identified four new homeologous chromosomes o f S. bayanus. The ARG4 probe confirmed the previously identified locat ion of chr. VIII (NAUMOV et al. 1992b). Using the MFalpha1 gene, anoth er chromosome besides chr. XVI was identified in some S. bayanus strai ns, suggesting translocation of this sequence to the S. bayanus chromo some that normally migrates to the position of chr. XI of S. cerevisia e.