Segregation of yeast polymorphic STA genes in meiotic recombinants and analysis of glucoamylase production

1996 ◽  
Vol 42 (12) ◽  
pp. 1190-1196 ◽  
Author(s):  
István Balogh ◽  
Anna Maráz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gel Electrophoresis ◽  
Glucose Repression ◽  
Gene Dosage ◽  
Pulsed Field Gel Electrophoresis ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
Yeast Strains ◽  
Low Levels ◽  
Sta Genes

Hybrid yeast strains were constructed using haploid Saccharomyces cerevisiae and Saccharomyces cerevisiae var. diastaticus strains to get haploid meiotic recombinants having more than one copy of STA1, STA2, and STA3 genes. STA genes were localized on the chromosomes by pulsed field gel electrophoresis. Working gene dosage effects were found among STA genes in liquid starch medium, indicating low levels of glucose repression. Growth of strains, however, was not influenced by their STA copy number.Key words: yeast, STA genes, gene dosage, karyotyping.

scholarly journals Structure and molecular analysis of RGR1, a gene required for glucose repression of Saccharomyces cerevisiae.

1990 ◽  
Vol 10 (8) ◽  
pp. 4130-4138 ◽  
Author(s):  
A Sakai ◽  
Y Shimizu ◽  
S Kondou ◽  
T Chibazakura ◽  
F Hishinuma
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gel Electrophoresis ◽  
Daughter Cell ◽  
Glucose Repression ◽  
Pulsed Field Gel Electrophoresis ◽  
Null Mutation ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Carboxy Terminal

An RGR1 gene product is required to repress expression of glucose-regulated genes in Saccharomyces cerevisiae. The abnormal morphology of rgr1 cells was studied. Scanning and transmission electron microscopic observations revealed that the cell wall of the daughter cell remained attached to that of mother cell. We cloned the RGR1 gene by complementation and showed that the cloned DNA was tightly linked to the chromosomal RGR1 locus. The cloned RGR1 gene suppressed all of the phenotypes caused by the mutation and encoded a 3.6-kilobase poly(A)+ RNA. The RGR1 gene is located on chromosome XII, as determined by pulsed-field gel electrophoresis, and we mapped rgr1 between gal2 and pep3 by genetic analysis. rgr1 was shown to be a new locus. We also determined the nucleotide sequence of RGR1, which was predicted to encode a 123-kilodalton protein. The null mutation resulted in lethality, indicating that the RGR1 gene is essential for growth. On the other hand, a carboxy-terminal deletion of the gene caused phenotypes similar to but more severe than those caused by the original mutation. The amount of reserve carbohydrates was reduced in rgr1 cells. Possible functions of the RGR1 product are discussed.

scholarly journals The SPT6 gene is essential for growth and is required for delta-mediated transcription in Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (2) ◽  
pp. 679-686 ◽  
Author(s):  
C D Clark-Adams ◽  
F Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Null Allele ◽  
Gene Dosage ◽  
Essential Gene ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
High Copy Number Plasmid ◽  
The Right ◽  
Extragenic Suppressors ◽  
Insertion Mutations

Mutations in the Saccharomyces cerevisiae SPT6 gene were originally identified as one class of extragenic suppressors of Ty and delta insertion mutations in the 5' noncoding regions of HIS4 and LYS2. We cloned SPT6 and constructed a null allele by gene disruption. Haploid spores carrying the spt6 null allele were inviable, indicating that the SPT6 gene is essential for mitotic growth. SPT6 was mapped to the right arm of chromosome VII, 44 centimorgans (cM) from ADE6 and 9 cM from CLY8. We showed that spt6 mutations suppress delta insertion mutations at the level of transcription but have no qualitative or quantitative effect on Ty transcription. In addition, we observed interesting SPT6 gene dosage effects. An SPT6 strain containing a high-copy-number plasmid clone of SPT6 showed suppression of delta insertion mutations, and a diploid strain with half its normal dose of SPT6 (SPT6/spt6 null) also exhibited suppression of delta insertion mutations. Therefore, having either too many or too few copies of SPT6 causes a mutant phenotype. Finally, this study and that in the accompanying paper (L. Neigeborn, J. L. Celenza, and M. Carlson, Mol. Cell. Biol. 7:679-686, 1986) showed that spt6 and ssn20 mutations (isolated as suppressors of snf2 and snf5 [sucrose nonfermenting] mutations) identify the same gene. SPT6 and SSN20 have the same genetic map position and share an identical restriction map. Furthermore, spt6 and ssn20 mutations fail to complement each other, and ssn20 mutations suppress solo delta insertion mutations at HIS4 and LYS2. These results, taken in conjunction with the SPT6 dosage effects and the fact that SPT6 is an essential gene, suggest that SPT6 plays a fundamental role in cellular transcription, perhaps by interaction with other transcription factors.

Structure and molecular analysis of RGR1, a gene required for glucose repression of Saccharomyces cerevisiae

1990 ◽  
Vol 10 (8) ◽  
pp. 4130-4138
Author(s):  
A Sakai ◽  
Y Shimizu ◽  
S Kondou ◽  
T Chibazakura ◽  
F Hishinuma
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gel Electrophoresis ◽  
Daughter Cell ◽  
Glucose Repression ◽  
Pulsed Field Gel Electrophoresis ◽  
Null Mutation ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Carboxy Terminal

An RGR1 gene product is required to repress expression of glucose-regulated genes in Saccharomyces cerevisiae. The abnormal morphology of rgr1 cells was studied. Scanning and transmission electron microscopic observations revealed that the cell wall of the daughter cell remained attached to that of mother cell. We cloned the RGR1 gene by complementation and showed that the cloned DNA was tightly linked to the chromosomal RGR1 locus. The cloned RGR1 gene suppressed all of the phenotypes caused by the mutation and encoded a 3.6-kilobase poly(A)+ RNA. The RGR1 gene is located on chromosome XII, as determined by pulsed-field gel electrophoresis, and we mapped rgr1 between gal2 and pep3 by genetic analysis. rgr1 was shown to be a new locus. We also determined the nucleotide sequence of RGR1, which was predicted to encode a 123-kilodalton protein. The null mutation resulted in lethality, indicating that the RGR1 gene is essential for growth. On the other hand, a carboxy-terminal deletion of the gene caused phenotypes similar to but more severe than those caused by the original mutation. The amount of reserve carbohydrates was reduced in rgr1 cells. Possible functions of the RGR1 product are discussed.

The SPT6 gene is essential for growth and is required for delta-mediated transcription in Saccharomyces cerevisiae

1987 ◽  
Vol 7 (2) ◽  
pp. 679-686
Author(s):  
C D Clark-Adams ◽  
F Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Null Allele ◽  
Gene Dosage ◽  
Essential Gene ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
High Copy Number Plasmid ◽  
The Right ◽  
Extragenic Suppressors ◽  
Insertion Mutations

Mutations in the Saccharomyces cerevisiae SPT6 gene were originally identified as one class of extragenic suppressors of Ty and delta insertion mutations in the 5' noncoding regions of HIS4 and LYS2. We cloned SPT6 and constructed a null allele by gene disruption. Haploid spores carrying the spt6 null allele were inviable, indicating that the SPT6 gene is essential for mitotic growth. SPT6 was mapped to the right arm of chromosome VII, 44 centimorgans (cM) from ADE6 and 9 cM from CLY8. We showed that spt6 mutations suppress delta insertion mutations at the level of transcription but have no qualitative or quantitative effect on Ty transcription. In addition, we observed interesting SPT6 gene dosage effects. An SPT6 strain containing a high-copy-number plasmid clone of SPT6 showed suppression of delta insertion mutations, and a diploid strain with half its normal dose of SPT6 (SPT6/spt6 null) also exhibited suppression of delta insertion mutations. Therefore, having either too many or too few copies of SPT6 causes a mutant phenotype. Finally, this study and that in the accompanying paper (L. Neigeborn, J. L. Celenza, and M. Carlson, Mol. Cell. Biol. 7:679-686, 1986) showed that spt6 and ssn20 mutations (isolated as suppressors of snf2 and snf5 [sucrose nonfermenting] mutations) identify the same gene. SPT6 and SSN20 have the same genetic map position and share an identical restriction map. Furthermore, spt6 and ssn20 mutations fail to complement each other, and ssn20 mutations suppress solo delta insertion mutations at HIS4 and LYS2. These results, taken in conjunction with the SPT6 dosage effects and the fact that SPT6 is an essential gene, suggest that SPT6 plays a fundamental role in cellular transcription, perhaps by interaction with other transcription factors.

scholarly journals Genetics advances and learning disability

2000 ◽  
Vol 176 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Walter J. Muir
Keyword(s):  
Learning Disability ◽  
Gene Dosage ◽  
Genetic Disorders ◽  
Molecular Medicine ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
Rapid Changes ◽  
Basic Understanding ◽  
Genetic Mechanisms ◽  
Dynamic Mutations

BackgroundMedicine is rapidly becoming molecular medicine, and little escapes the grasp of modern genetics. Most disorders associated with learning disability have at least a genetic component influencing their expression; in many disorders, disturbances of genetic mechanisms play a pivotal role.AimsDynamic mutations, imprinting mechanisms and gene-dosage effects are explained with reference to genetic disorders that lead to learning disability.MethodA review of recent important studies in the genetics of learning disability.ResultsA host of new genetic connections to conditions associated with learning disability have been made.ConclusionsA basic understanding of these genetic connections is important for all learning disability psychiatrists if they are to follow the rapid changes – already beginning to influence our practice – that hold immense promise for the future.

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