Yeast chromosomes have been significantly reshaped during their evolutionary history.
The structure of the first eukaryotic genome, belonging to Saccharomyces cerevisiae, has been deduced; however, very little is known about its origin. In order to trace events that led to the current state of the Saccharomyces nuclear genomes, random fragments of genomic DNA from three yeasts were sequenced and compared to the S. cerevisiae database sequence. Whereas, S. cerevisiae and Saccharomyces bayanus show perfect synteny, a significant portion of the analysed fragments from Saccharomyces servazzii and Saccharomyces kluyveri show a different arrangement of genes when compared to S. cerevisiae. When the sequenced fragments were probed to the corresponding karyotype, a group of genes present on a single chromosome of S. servazzii and S. kluyveri had homologues scattered on several S. cerevisiae chromosomes. Apparently, extensive reorganisation of the chromosomes has taken place during evolution of the Saccharomyces yeasts. In addition, while one gross duplication could have taken place, at least a few genes have been duplicated independently at different time-points in the evolution.
Langkjaer
R B
RB
Department of Microbiology, Technical University of Denmark, Building 301, DK-2800 Lyngby, Denmark.
Nielsen
M L
ML
Daugaard
P R
PR
Liu
W
W
Piskur
J
J
D015825:Chromosomes, Fungal / Q000235:genetics*; D003001:Cloning, Molecular; D004251:DNA Transposable Elements / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D019992:Databases as Topic; D019143:Evolution, Molecular; D020440:Gene Duplication; D020131:Genes, Duplicate / Q000235:genetics; D016681:Genome, Fungal; D015698:Genomic Library; D007621:Karyotyping; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D020161:Physical Chromosome Mapping; D012335:RNA, Ribosomal / Q000235:genetics; D012440:Saccharomyces / Q000235:genetics*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
D004251:DNA Transposable Elements; D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal; D012335:RNA, Ribosomal