Search results for "saccharomyces"

Molecular characterisation of the species of the genus Zygosaccharomyces.

2003

The restriction fragments polymorphisms of the mitochondrial DNA and the PCR fragment that comprised the internal transcribes spacers and the 5.8S rRNA gene, together with the electrophoretic karyotypes of 40 strains from the 10 species of the genus Zygosaccharomyces, including the new species Z. lentus were examined. The RFLP's of the ITS-5.8S region showed a specific restriction pattern for each species, including the new species Z. lentus. The only exception were the species Z. cidri and Z. fermentati that produced identical restriction profiles. The electrophoretic chromosome patterns confirmed the differences between the species of this genus, including the phylogenetic closest species…

Functional analysis of yeast gene families involved in metabolism of vitamins B1and B6

2002

In order to clarify their physiological functions, we have undertaken a characterization of the three-membered gene families SNZ1-3 and SNO1-3. In media lacking vitamin B(6), SNZ1 and SNO1 were both required for growth in certain conditions, but neither SNZ2, SNZ3, SNO2 nor SNO3 were required. Copies 2 and 3 of the gene products have, in spite of their extremely close sequence similarity, slightly different functions in the cell. We have also found that copies 2 and 3 are activated by the lack of thiamine and that the Snz proteins physically interact with the thiamine biosynthesis Thi5 protein family. Whereas copy 1 is required for conditions in which B(6) is essential for growth, copies 2 …

The primary structure of cytoplasmic initiator tRNAMetfromSchizosaccharomyces pombe

1993

Construction of a Trp commercial baker?s yeast strain by using food-safe-grade dominant drug resistance cassettes

2003

We have designed a food-safe-grade module for gene disruptions in commercial baker's yeast strains, which contains the G418 resistance cassette, KanMX4, flanked by direct repeats from the MEL1 gene of Saccharomyces cerevisiae. This module was used to obtain a Trp(-) auxotrophic mutant of the polyploid HY strain by successive targeting to the TRP1 locus and later in vivo excision of the kan(r) marker. Southern blot analysis indicated that HY contains five copies of the TRP1 gene. However, after four disruption rounds, a strain named HYtrpM(4), unable to grow in the absence of tryptophan, was selected. Southern and Northern analysis of HYtrpM(4) cells showed that a remaining functional wild-t…

Genomic response programs of Saccharomyces cerevisiae following protoplasting and regeneration.

2007

Abstract Global transcription profiling during regeneration of Saccharomyces cerevisiae protoplasts was explored. DNA microarrays measured the expression of 6388 genes and wall removal resulted initially in over-expression of 861 genes that decayed later on, a behaviour expected from a transient stress response. Kinetics of expression divided the genes into 25 clusters. Transcription of the genes from clusters 14–25 was initially up-regulated, suggesting that the grouped genes permitted cell adaptation to the removal of the wall. Clustering of genes involved in “wall structure and biosynthesis” showed that most of them had initially low levels of expression that increased along the process.…

A rapid method for the screening of plasmids in transformed yeast strains

1988

A method for the rapid screening of plasmids in yeast cells has been developed. The method is an adaptation of the currently used alkaline lysis methods forEscherichia coli plasmids. Following the conditions described, several dozen ofSaccharomyces cerevisiae-transformed clones can be analyzed for their plasmid content in less than 2 h. The plasmids obtained by this procedure are suitable for restriction analysis or forE. coli andS. cerevisiae transformation.

Transcriptional and Structural Study of a Region of Two Convergent Overlapping Yeast Genes

1999

The exceptionally close packing of many yeast genes and other chromosomal elements raises the question of how those elements are functionally insulated. All published work shows that natural insulators are very effective, but transcriptional interference (TI) occurs if they are mutated or if their natural context is altered. Mechanisms to avoid TI are poorly understood, but are thought to involve an interplay of cis sequences and trans factors in a chromatin context. We have studied the case of two convergent closely packed ORFs (56 bp of separation) in chromosome IX of Saccharomyces cerevisiae. mRNAs from POT1 and YIL161w overlap by up to 115 nt. Convergent transcription causes a small but…

SRC1: an intron-containing yeast gene involved in sister chromatid segregation

2001

Analysis of a three-member gene family in the yeast Saccharomyces cerevisiae has allowed the discovery of a new gene that comprises two contiguous open reading frames previously annotated as YML034w and YML033w. The gene contains a small intron with two alternative 5′ splicing sites. It is specifically transcribed during G2/M in the cell cycle and after several hours of meiosis induction. Splicing of the mRNA is partially dependent on NAM8 but does not vary during meiosis or the cell cycle. Deletion of the gene induces a shortening of the anaphase and aggravates the phenotype of scc1 and esp1 conditional mutants, which suggests a direct role of the protein in sister chromatid separation. Co…

A novel approach for the improvement of stress resistance in wine yeasts

2006

During wine production yeast cells are affected by several stress conditions that could affect their viability and fermentation efficiency. In this work we describe a novel genetic manipulation strategy designed to improve stress resistance in wine yeasts. This strategy involves modifying the expression of the transcription factor MSN2, which plays an important role in yeast stress responses. The promoter in one of the genomic copies of this gene has been replaced by the promoter of the SPI1 gene, encoding for a cell wall protein of unknown function. SPI1 is expressed at late phases of growth and is regulated by Msn2p. This modification allows self-induction of MSN2 expression. MSN2 gene tr…

Genetic manipulation of HSP26 and YHR087W stress genes may improve fermentative behaviour in wine yeasts under vinification conditions

2008

Throughout wine production yeast cells are affected by a plethora of stress conditions that compromise their ability to carry out the whole process. In recent years important knowledge about the mechanisms involved in stress response in both laboratory and wine yeast strains has been obtained. Several studies have indicated that a correlation exists between stress resistance, expression of stress response genes and fermentative behaviour. In this work we introduce several genetic manipulations in two genes induced by several stress conditions: HSP26 (which encodes a heat shock protein) and YHR087W (encoding a protein of unknown function) in two different wine yeasts, ICV16 and ICV27. These …