Isolation and characterization of Schizosaccharomyces pombe mutants with defective NAD-dependent malic enzyme

1986 ◽  
Vol 32 (6) ◽  
pp. 481-486 ◽  
Author(s):  
C. Osothsilp ◽  
R. E. Subden
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Malic Enzyme ◽  
Pool Analysis ◽  
Starch Gel Electrophoresis ◽  
Wild Type ◽  
Isolation And Characterization ◽  
Starch Gel ◽  
Colony Color ◽  
Color Indicator

To obtain NAD-dependent malic enzyme mutants of Schizosaccharomyces pombe, a colony color indicator screening system was developed. Mutants defective for malic acid utilization (mau mutants) are yellow, while wild-type colonies are blue on the defined bromcresol green based indicator medium. NAD-dependent malic enzyme mutants were distinguished from other mau mutants by subsequent, starch gel electrophoresis, spectrophotometry, complementation tests, and intermediate pool analysis with cell-free extracts.

scholarly journals Isolation and characterization of regulatory mutants from Schizosaccharomyces pombe involved in thiamine-regulated gene expression.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 445-449
Author(s):  
A M Schweingruber ◽  
H Fankhauser ◽  
J Dlugonski ◽  
C Steinmann-Loss ◽  
M E Schweingruber
Keyword(s):  
Acid Phosphatase ◽  
Schizosaccharomyces Pombe ◽  
Mrna Levels ◽  
Wild Type ◽  
Transcription Control ◽  
Isolation And Characterization ◽  
Gene Coding ◽  
Thiamine Transport ◽  
Regulated Gene Expression

Abstract Mutants from Schizosaccharomyces pombe deficient in the regulation of thiamine-repressible acid phosphatase have been isolated. Mutants expressing derepressed levels of the enzyme in the presence and absence of thiamine map in three genes, tnr1, tnr2 and tnr3. mRNA levels of the pho4 gene (coding for thiamine repressible acid phosphatase) and another thiamine-regulatable gene, thi3 (coding for a thiamine biosynthetic enzyme and corresponding to nmt1) are constitutively synthesized in the mutants. The mutants also exhibit constitutive thiamine transport which is thiamine repressible in wild type. The tnr3 mutants reveal a 10-20-fold higher intracellular thiamine level than tnr1 and tnr2 mutants and wild type. Mutants expressing repressed levels of thiamine-repressible acid phosphatase map in gene thi1. No or little amounts of pho4- and nmt1-specific mRNA can be detected. These mutants are impaired in thiamine uptake and are thiamine auxotrophic due to the inability to synthesize the thiazole moiety of the thiamine molecule. All tested tnr and thi1 alleles are recessive, and thi1 mutations are epistatic over tnr mutations. We assume that the thi1 and tnr genes are involved in thiamine-mediated transcription control.

scholarly journals Isolation and characterization of Schizosaccharomyces pombe mutants affected in mitotic recombination.

Genetics ◽  
1991 ◽  
Vol 128 (3) ◽  
pp. 495-504
Author(s):  
A Gysler-Junker ◽  
Z Bodi ◽  
J Kohli
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Mitotic Recombination ◽  
Selective Medium ◽  
Intragenic Recombination ◽  
Crossing Over ◽  
Wild Type ◽  
Isolation And Characterization ◽  
Mitotic Gene Conversion ◽  
Type Frequency

Abstract A haploid Schizosaccharomyces pombe strain carrying a heteroallelic duplication of the ade6 gene was used to isolate mitotic recombination-deficient mutants. Recombination between the different copies of the ade6 gene can lead to Ade+ segregants. These are observed as growing papillae when colonies of a suitable size are replicated onto selective medium. We isolated mutants which show an altered papillation phenotype. With two exceptions, they exhibit a decrease in the frequency of mitotic recombination between the heteroalleles of the duplication. The two other mutants display a hyper-recombination phenotype. The 12 mutations were allocated to at least nine distinct loci by recombination tests. Of the eight rec mutants analyzed further, six were also affected in mitotic intergenic recombination in the intervals cen2-mat or cen3-arg 1. No effect on mitotic intragenic recombination was observed. These data suggest that mitotic gene conversion and crossing over can be separated mutationally. Meiotic recombination occurs at the wild-type frequency in all mutants investigated.

scholarly journals Isolation and Characterization of Protein Bodies From Developing Wheat Endosperm

1963 ◽  
Vol 16 (2) ◽  
pp. 375 ◽  
Author(s):  
Janet SD Graham ◽  
RK Morton ◽  
JK Raison
Keyword(s):  
Electron Microscopy ◽  
Gel Electrophoresis ◽  
Starch Gel Electrophoresis ◽  
Separation And Purification ◽  
Isolation And Characterization ◽  
Dense Bodies ◽  
Starch Gel ◽  
Slow Moving ◽  
Protein Components

Procedures are described for separation and purification of electron-dense bodies previously observed in intact endosperm by electron microscopy. Isolated bodies consist largely of protein. By starch-gel electrophoresis, the bodies contain predominantly slow-moving protein components similf1l' to those found in acetic acid extracts of whole endosperm.

scholarly journals Haemoglobin polymorphism in selected farm animals: A review

2014 ◽  
Vol 30 (3) ◽  
pp. 377-390 ◽  
Author(s):  
S.S.A. Egena ◽  
R.O. Alao
Keyword(s):  
Genetic Improvement ◽  
Raw Materials ◽  
Farm Animals ◽  
Starch Gel Electrophoresis ◽  
Gene Frequencies ◽  
Starch Gel ◽  
And Performance ◽  
Polypeptide Chains ◽  
Degree Of Similarity

Biochemical diversity or polymorphism is the occurrence of varieties attributed to biochemical differences which are under genetic control. It has created a leeway for the genetic improvement of farm animals. This is because it can be used as a useful tool for the characterization of livestock breeds and population. This way, the degree of similarity or differences within and between breeds can be ascertained and this differences or similarity are important raw materials for genetic improvement of animals. Data obtained on gene frequencies and genotypes through polymorphism study makes it not only possible to compare the gene stocks of animals, the possible effects of the genes on reproductive and performance traits, but also study genetic variability under different environmental conditions of selection. This study was carried out to review haemoglobin (Hb) polymorphism in selected farm animals with the view of finding out the type of polymorphism observed by starch gel electrophoresis due to variation in the amino acid sequence in the polypeptide chains of Hb. The review showed clearly that there is a gene-controlled diversity in the different farm animals considered. This could serve as a reference point for future studies earmarked for the improvement of the animals possibly via marker-assisted selection.

scholarly journals Isolation and characterization of the SPT2 gene, a negative regulator of Ty-controlled yeast gene expression.

1985 ◽  
Vol 5 (7) ◽  
pp. 1543-1553 ◽  
Author(s):  
G S Roeder ◽  
C Beard ◽  
M Smith ◽  
S Keranen
Keyword(s):  
Gene Product ◽  
Regulatory Region ◽  
Negative Regulator ◽  
Transcriptional Level ◽  
Wild Type ◽  
Isolation And Characterization ◽  
Mutant Strains ◽  
Insertion Mutations ◽  
His4 Gene

The his4-917 mutation of Saccharomyces cerevisiae results from the insertion of the Ty element Ty917 into the regulatory region of the HIS4 gene and renders the cell His-. The hist4-912 delta mutant, which carries a solo delta in the 5'-noncoding region of HIS4, is His+ at 37 degrees C but His- at 23 degrees C. Both these mutations interfere with HIS4 expression at the transcriptional level. The His- phenotype of both insertion mutations is suppressed by mutations at the SPT2 locus. The product of the wild-type SPT2 gene apparently represses HIS4 transcription in these mutant strains; this repression is relieved when the SPT2 gene is destroyed by mutation. The repression of transcription by SPT2 presumably results from an interaction between the SPT2+ gene product and Ty or delta sequences. In this paper, we report the cloning and DNA sequence analysis of the wild-type SPT2 gene and show that the gene is capable of encoding a protein of 333 amino acids in length. In addition, we show that a dominant mutation of the SPT2 gene results from the generation of an ochre codon which is presumed to lead to a shortened SPT2 gene product.

Isolation and characterization of the Schizosaccharomyces pombe rad3 gene, involved in the DNA damage and DNA synthesis checkpoints

Gene ◽  
1992 ◽  
Vol 119 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Brent L. Seaton ◽  
Jennifer Yucel ◽  
Per Sunnerhagen ◽  
Suresh Subramani
Keyword(s):  
Dna Damage ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Isolation And Characterization
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