Comparative genomics of protoploid Saccharomycetaceae
The Genolevures Consortium
Our knowledge of yeast genomes remains largely dominated by the
extensive studies on Saccharomyces cerevisiae and the
consequences of its ancestral duplication, leaving the evolution of the
entire class of hemiascomycetes only partly explored.
We concentrate here on five species of Saccharomycetaceae, a large
subdivision of hemiascomycetes, that we call
‘‘protoploid’’ because they diverged from the S. cerevisiae lineage
prior to its genome duplication. We determined the
complete genome sequences of three of these species: Kluyveromyces
(Lachancea) thermotolerans and Saccharomyces (Lachancea)
kluyveri (two members of the newly described Lachancea clade), and
Zygosaccharomyces rouxii. We included in our comparisons
the previously available sequences of Kluyveromyces lactis and Ashbya
(Eremothecium) gossypii. Despite their broad evolutionary
range and significant individual variations in each lineage, the five
protoploid Saccharomycetaceae share a core repertoire of
approximately 3300 protein families and a high degree of conserved
synteny. Synteny blocks were used to define gene
orthology and to infer ancestors. Far from representing minimal genomes
without redundancy, the five protoploid yeasts
contain numerous copies of paralogous genes, either dispersed or in
tandem arrays, that, altogether, constitute a third of
each genome. Ancient, conserved paralogs as well as novel,
lineage-specific paralogs were identified.
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Klaas Vandepoele, PhD
Tel. 32 (0)9 33 13822
VIB Department of Plant Systems Biology, Ghent University
Technologiepark 927, 9052 Gent, Belgium
E-mail: Klaas.Vandepoele@psb.vib-ugent.be
Website: http://bioinformatics.psb.ugent.be/
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