Genomic Exploration of the Hemiascomycetous Yeasts: 19. Ascomycetes-specific genes

AbstractComparisons of the 6213 predicted Saccharomyces cerevisiae open reading frame (ORF) products with sequences from organisms of other biological phyla differentiate genes commonly conserved in evolution from ‘maverick’ genes which have no homologue in phyla other than the Ascomycetes. We show that a majority of the ‘maverick’ genes have homologues among other yeast species and thus define a set of 1892 genes that, from sequence comparisons, appear ‘Ascomycetes-specific’. We estimate, retrospectively, that the S. cerevisiae genome contains 5651 actual protein-coding genes, 50 of which were identified for the first time in this work, and that the present public databases contain 612 predicted ORFs that are not real genes. Interestingly, the sequences of the ‘Ascomycetes-specific’ genes tend to diverge more rapidly in evolution than that of other genes. Half of the ‘Ascomycetes-specific’ genes are functionally characterized in S. cerevisiae, and a few functional categories are over-represented in them

La construction d’une discipline universitaire : la génétique à la faculté des sciences de Paris de 1946 à 1970

L'accession de la génétique au rang de discipline enseignée à la faculté des sciences de Paris en 1946 est liée à l'attribution de la première chaire universitaire de génétique à Boris Ephrussi. Au milieu du XXème siècle, les professeurs Boris Ephrussi, Philippe L'Héritier, Georges Teissier et Georges Rizet, puis Piotr Slonimski et Madeleine Gans, ont été les initiateurs d'une pédagogie novatrice appuyée sur une recherche scientifique originale. Durant les décennies suivantes, les progrès de la recherche ont entrainé des remaniements importants de l'enseignement mais le lien organique entre recherche et enseignement s’est toujours maintenu.Promoting Genetics to the rank of discipline taught at the Faculty of Sciences of Paris in 1946 is linked to the first university chair of Genetics, awarded to Boris Ephrussi. In the mid-twentieth century, professors Boris Ephrussi, Philippe L’Héritier, Georges Teissier and Georges Rizet, later joined by Piotr Slonimski and Madeleine Gans, initiated innovative teaching methods based on original scientific research. Over the following decades, advances in the research led to major changes in education, but the organic link between research and teaching has always been maintained

Random exploration of the Kluyveromyces lactis genome and comparison with that of Saccharomyces cerevisiae.

The genome of the yeast Kluyveromyces lactis was explored by sequencing 588 short tags from two random genomic libraries (random sequenced tags, or RSTs), representing altogether 1.3% of the K. lactis genome. After systematic translation of the RSTs in all six possible frames and comparison with the complete set of proteins predicted from the Saccharomyces cerevisiae genomic sequence using an internally standardized threshold, 296 K.lactis genes were identified of which 292 are new. This corresponds to approximately 5% of the estimated genes of this organism and triples the total number of identified genes in this species. Of the novel K.lactis genes, 169 (58%) are homologous to S.cerevisiae genes of known or assigned functions, allowing tentative functional assignment, but 59 others (20%) correspond to S.cerevisiae genes of unknown function and previously without homolog among all completely sequenced genomes. Interestingly, a lower degree of sequence conservation is observed in this latter class. In nearly all instances in which the novel K.lactis genes have homologs in different species, sequence conservation is higher with their S.cerevisiae counterparts than with any of the other organisms examined. Conserved gene order relationships (synteny) between the two yeast species are also observed for half of the cases studied

A family of low and high copy replicative, integrative and single-strandedS. cerevisiae/E. coli shuttle vectors

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Large-scale Exploration of Growth Inhibition Caused by Overexpression of Genomic Fragments in Saccharomyces cerevisiae

International audienceWe have screened the genome of Saccharomyces cerevisiae for fragments that confer a growth-retardation phenotype when overexpressed in a multicopy plasmid with a tetracycline-regulatable (Tet-off) promoter. We selected 714 such fragments with a mean size of 700 base-pairs out of around 84,000 clones tested. These include 493 in-frame open reading frame fragments corresponding to 454 distinct genes (of which 91 are of unknown function), and 162 out-of-frame, antisense and intergenic genomic fragments, representing the largest collection of toxic inserts published so far in yeast

Genomic exploration of the hemiascomycetous yeasts: 3. Methods and strategies used for sequence analysis and annotation

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