Comparative Genomic Hybridization Provides New Insights Into the Molecular Taxonomy of the Saccharomyces Sensu Stricto Complex

Abstract

The science of taxonomy is constantly improving as new techniques are developed. Current practice is to construct phylogenetic trees based on the analysis of the DNA sequence of single genes, or parts of single genes. However, this approach has recently been brought into question as several tree topologies may be produced for the same clade when the sequences for various different genes are used. The availability of complete genome sequences for several organisms has seen the adoption of microarray technology to construct molecular phylogenies of bacteria, based on all of the genes. Similar techniques have been used to reveal the relationships between different strains of the yeast Saccharomyces cerevisiae. We have exploited microarray technology to construct a molecular phylogeny for the Saccharomyces sensu stricto complex of yeast species, which is based on all of the protein-encoding genes revealed by the complete genome sequence of the paradigmatic species, S. cerevisiae. We also analyze different strains of S. cerevisiae itself, as well as the putative species S. boulardii. We show that in addition to the phylogeny produced, we can identify and analyze individual ORF traits and interpret the results to give a detailed explanation of evolutionary events underlying the phylogeny.

Alternative Splicing of PTC7 inSaccharomyces cerevisiaeDetermines Protein Localization

“…We next carried out a multiple sequence alignment on all 12 PTC7 introns (Notredame et al 2000). There was a high degree of similarity across the entire intron among the five most closely related Saccharomyces yeast species (S. cerevisiae, S. paradoxus, S. mikatae, S. kudriavzevii, and S. bayanus) (Figure 2, gray highlight); these yeast species belong to the sensu stricto complex (Edwards-Ingram et al 2004) and a large degree of sequence conservation was expected, which likely reflects functional conservation. Outside of the sensu stricto complex, sequence conservation was concentrated at the three major splice signals (59-splice site, branch point, and 39-splice site) (Figure 2).…”

Brewing and the taxonomy of brewer's yeast.

“…V molekulách DNA jsou zakódová-ny informace o struktuře všech buněčných proteinů a o struktuře molekul ribonukleových kyselin (RNA), které se účastní syntézy proteinů. Nezávisle na vlivech vnějšího prostředí se informace uložené v DNA normálně nemění [10,17,18,19,20].…”

“…DNA molecules contain encoded information about the structure of all cell proteins and about the structure of ribonucleic acid molecules (RNA) that participate in protein synthesis. The information contained in DNA under normal circumstances does not change irrespective of environmental effects [10,17,18,19,20]. One of the oldest molecular techniques is the determination of the content of guanine and cytosine (% G+C) of nuclear and mitochondrial DNA.…”

Saccharomyces cerevisiae var. boulardii – Probiotic Yeast

“…Thus there is a need for a valuable molecular markers able to distinguish among strains and establish appropriate methods for the identification of probiotic strains of the Sb. Such a method could be, for example, microsatellite length polymorphism, having a discriminatory power of 99% [15,23], restriction fragment length polymorphism [24], full genome hybridization [14], randomly amplified polymorphic DNA [25], GeneChip hybridization [11], artificial neural network-assisted Fourier-transform infrared spectroscopy [26] or multilocus enzyme electrophoresis [27]. These identification methods enable the discrimination between various strains but are not necessarily related to mechanisms of probiotic activity.…”

“…Typing RFLPs or PCR-(ex 5.8S rDNA) failed to distinguish Sb from S. cerevisiae [12] Do not use galactose [13] Use galactose Asporogenous in contrast to S. cerevisiae but may produce fertile hybrids with of S. cerevisiae strains [11] Sporogenous Lost all intact Ty1/2 elements [14]. Contains several Ty1/2 elements Microsatellite typing shows genotypic differences [15] Trisomic for chromosome IX There are stable strains with various ploidy Table 1.…”