Genomic Exploration of the Hemiascomycetous Yeasts: 5. Saccharomyces bayanus var. uvarum

Saccharomyces byanus var. uvarum investigated here is the species closest t o Saccharomyces cerevisiae . Random sequence tags (RSTs) allowed us to iden tify homologues to 2789 open reading frames (ORFs) in S. cervisiae, ORFs du plicated in S. uvarum but not in S.cervisiae, centromeres, tRNAs, homologue s of Ty1/2 and Ty4 retrotransposons, and a complete rDNA repeat. Only 13 RS Ts seem to be homologous to sequences in other organisms but not in S.cervi siae. As the synteny between the two species is very high, cases in which s ynteny is lost suggest special mechanisms of genome evolution. The correspo nding RSTs revealed that S, uvarum can exist without any S, cervisiae DNA i ntrogression, Accession numbers are from AL397139 to AL402278 in the EMBL d atabank, (C) 2000 Federation of European Biochemical Societies. Published b y Elsevier Science B.V. All rights reserved.