Quantitative Selection of Respiratory Deficient Mutants in Yeasts by Triphenyltetrazolium Chloride

1972 ◽  
Vol 27 (3) ◽  
pp. 252-256 ◽  
Author(s):  
V. Bachofen ◽  
R. J. Schweyen ◽  
K. Wolf ◽  
F. Kaudewitz

Triphenyltetrazolium chloride exhibits a strong growth inhibition in respiratory competent cells but shows only minor effects in respiratory deficient mutants of Saccharomyces cerevisiae and Schizosaccharomyces pombe. Use of this dye thus allows rapid selection of rarely occurring respiratory deficient mutants, showing karyotic as well as extrakaryotic inheritance. Mutation induction by tetrazolium chloride was not observed. The results favour the hypothesis that triphenyltetrazolium chloride interferes with the terminal oxidase of the respiratory chain.

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 553-562
Author(s):  
Margaret I Kanipes ◽  
John E Hill ◽  
Susan A Henry

Abstract The isolation of mutants of Schizosaccharomyces pombe defective in the synthesis of phosphatidylcholine via the methylation of phosphatidylethanolamine is reported. These mutants are choline auxotrophs and fall into two unlinked complementation groups, cho1 and cho2. We also report the analysis of the cho1+ gene, the first structural gene encoding a phospholipid biosynthetic enzyme from S. pombe to be cloned and characterized. The cho1+ gene disruption mutant (cho1Δ) is viable if choline is supplied and resembles the cho1 mutants isolated after mutagenesis. Sequence analysis of the cho1+ gene indicates that it encodes a protein closely related to phospholipid methyltransferases from Saccharomyces cerevisiae and rat. Phospholipid methyltransferases encoded by a rat liver cDNA and the S. cerevisiae OPI3 gene are both able to complement the choline auxotrophy of the S. pombe cho1 mutants. These results suggest that both the structure and function of the phospholipid N-methyltransferases are broadly conserved among eukaryotic organisms.


2002 ◽  
Vol 3 (3) ◽  
pp. 221-225

In recent months a bumper crop of genomes has been completed, including the fission yeast (Schizosaccharomyces pombe) and rice (Oryza sativa). Two large-scale studies ofSaccharomyces cerevisiaeprotein complexes provided a picture of the eukaryotic proteome as a network of complexes. Amongst the other stories of interest was a demonstration that proteomic analysis of blood samples can be used to detect ovarian cancer, perhaps even as early as stage I.


Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1451-1461 ◽  
Author(s):  
Yasuhiro Tsutsui ◽  
Takashi Morishita ◽  
Hiroshi Iwasaki ◽  
Hiroyuki Toh ◽  
Hideo Shinagawa

Abstract To identify Schizosaccharomyces pombe genes involved in recombination repair, we identified seven mutants that were hypersensitive to both methyl methanesulfonate (MMS) and γ-rays and that contained mutations that caused synthetic lethality when combined with a rad2 mutation. One of the mutants was used to clone the corresponding gene from a genomic library by complementation of the MMS-sensitive phenotype. The gene obtained encodes a protein of 354 amino acids whose sequence is 32% identical to that of the Rad57 protein of Saccharomyces cerevisiae. An rhp57 (RAD57 homolog of S. pombe) deletion strain was more sensitive to MMS, UV, and γ-rays than the wild-type strain and showed a reduction in the frequency of mitotic homologous recombination. The MMS sensitivity was more severe at lower temperature and was suppressed by the presence of a multicopy plasmid bearing the rhp51 gene. An rhp51 rhp57 double mutant was as sensitive to UV and γ-rays as an rhp51 single mutant, indicating that rhp51 function is epistatic to that of rhp57. These characteristics of the rhp57 mutants are very similar to those of S. cerevisiae rad57 mutants. Phylogenetic analysis suggests that Rhp57 and Rad57 are evolutionarily closest to human Xrcc3 of the RecA/Rad51 family of proteins.


Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 147-154 ◽  
Author(s):  
Douglas J Kominsky ◽  
Peter E Thorsness

Abstract Organisms that can grow without mitochondrial DNA are referred to as “petite-positive” and those that are inviable in the absence of mitochondrial DNA are termed “petite-negative.” The petite-positive yeast Saccharomyces cerevisiae can be converted to a petite-negative yeast by inactivation of Yme1p, an ATP- and metal-dependent protease associated with the inner mitochondrial membrane. Suppression of this yme1 phenotype can occur by virtue of dominant mutations in the α- and γ-subunits of mitochondrial ATP synthase. These mutations are similar or identical to those occurring in the same subunits of the same enzyme that converts the petite-negative yeast Kluyveromyces lactis to petite-positive. Expression of YME1 in the petite-negative yeast Schizosaccharomyces pombe converts this yeast to petite-positive. No sequence closely related to YME1 was found by DNA-blot hybridization to S. pombe or K. lactis genomic DNA, and no antigenically related proteins were found in mitochondrial extracts of S. pombe probed with antisera directed against Yme1p. Mutations that block the formation of the F1 component of mitochondrial ATP synthase are also petite-negative. Thus, the F1 complex has an essential activity in cells lacking mitochondrial DNA and Yme1p can mediate that activity, even in heterologous systems.


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