Organization of specific genomic regions of Zygosaccharomyces rouxii and Pichia sorbitophila: comparison with Saccharomyces cerevisiae

The genomes of Zygosaccharomyces rouxii and Pichia sorbitophila were partia lly explored. The genome of Z. rouxii CBS 732 consists of seven chromosomes with an approximate size of 1.0-2.75 Mb, 12.8 Mb in total, Five of the chr omosomes were labelled with specific probes, Three Z. rouxii genomic DNA fr agments mere sequenced; all 10 ORFs found mere without introns and they hav e homologues in S, cerevisiae. Gene order comparison revealed that the orga nization is partially conserved in both species. The genome of P. sorbitoph ila CBS 7064 consists of seven chromosomes with an approximate size of 1.0- 2.9 Mb, 13.9 Mb in total, Three of the chromosomes were labelled with speci fic probes. The sequencing of a 5.2 kb genomic DNA fragment revealed three ORFs, but no conservation of their organization was found, although all of them have their respective homologues in S, cerevisiae. According to our re sults, the presence of two overlapping ORFs in S, cerevisiae (YJL107c-YJL10 8c) could be interpreted as the result of a frameshift mutation. The Access ion Nos of the sequenced DIVA fragments are: Y18561, AJ25115, Y18560 and Y1 8559. Copyright (C) 2000 John Wiley & Sons, Ltd.