Petite mutants

Tsai, H.F., Krol, A.A., Sarti, K.E.. and Bennett, J.E. (2006) Candida glabrata PDRl, a transcriptional regulator of a pleiotropic drug resistance network, mediates azole resistance in clinical isolates and petite mutants. Antimicrobial Agents and Chemotherapy, 50. 1384—1392. 

Chabasse, D., and Bouchara, J.P. (2004) Mechanisms of azole resistance in petite mutants of Candida glabrata. Antimicrobial Agents and Chemotherapy, 48, 1788-1796. 

Cheng, S., Clancy, C.J., Nguyen, KT, Clapp, W, and Nguyen, M.H. (2007) A Candida albicans petite mutant strain with uncoupled oxidative phosphorylation overexpresses MDRl and has diminished susceptibility to fluconazole and voriconazole. Antimicrobial Agents and Chemotherapy, 51, 1855-1858. 

Figure 1.4. Left panel Gradient elution by phosphate buffer in the presence of 1 per cent formaldehyde of bovine DNA A, native DNA B, heat-denatured (100°) DNA C, a 1 1 mixture of native and heat-denatured (100°) DNA. (From Bernardi, 1965b). Right panel Chromatography of DNA preparations A from wild-type yeast cells B from a cytoplasmic petite mutant. The three peaks eluted by the phosphate gradient correspond to RN A, nuclear DNA (a) and mitochondrial DNA (b). W and G indicate washing and...

Figure 2.7. Restriction enzyme maps of the repeating units of the mitochondrial genomes of several spontaneous petite mutants. The molecular weights of the repeat units are indicated, along with the positions of Hae III (A), Hpa II (T) and other restriction sites. In the case of a.n, five isolated Hpa II sites and Mine II site are not shown. The broken lines indicate corresponding restriction sites in dilferent repeat units. (From...

The first determination of the nucleotide sequence of the repeat unit of the mitochondrial genome of the spontaneous petite mutant ai iR/ i (Gaillard and Beniardi, 1979 Fig. 2.8)... 

A functional evidence that ori sequences are indeed involved in the replication of the mitochondrial genome came from crosses of spontaneous petites, characterized in their mitochondrial genome and their suppressivity, with wild-type cells (de Zamaroczy et al., 1979 1981 Goursot et al., 1980). In the suppressivity test, petite mutants are crossed with... 

These results are similar to the in vivo data on the effect of growth temperature on the structure and function of ori sequences in the mitochondrial genome of yeast (Goursot et al., 1988 see Part 2). In this case too, increasing temperature from 28°C to 33°C led to the melting of AT stems in the ori sequence of some petite mutants and to the consequent decrease of replicative ability. These results demonstrate direct (reversible) temperature effects on the secondary (and tertiary) structures of DNA and RNA. 

Bernardi G., Carnevali F., Nicolaieff A., Piperno G., Tecce G. (1968). Separation and characterization of a satellite DNA from a yeast cytoplasmic petite mutant. J. Mol. Biol. 37 493-505. 

Bernardi G., Baldacci G., Culard F., Faugeron-Fonty G., Gaillard C., Goursot R., Strauss F., de Zamaroczy M. (1980b). Excision and replication of mitochondrial genomes from spontaneous petite mutants of yeast. In FEBS Symposium on DNA (J. Sponar and S. Zadrazil, eds.) pp. 77-84, Pergamon Press, New York, NY, USA. 

Gaillard C. and Bernardi G. (1979). The nucleotide sequence of the mitochondrial genome of a spontaneous petite mutant in yeast. Mol. Gen. Genet. 174 335-337. 

Goursot R., de Zamaroczy M., Baldacci G., Bernard G. (1980). Supersuppressive petite mutants in yeast. Current Genet. 1 173-176. 

Goursot R., Mangin M., Bernard G. (1982). Surrogate origins of replication in the mitochondrial genome of ori petite mutants of yeast. EMBO J. 1 705-711. 

Lewin A., Morimoto R., Rabinowitz M. (1978). Restriction enzyme analysis of mitochondrial DNAs of petite mutants of yeast classification of petites, and deletion mapping of mitochondrial genes. Mol. Gen. Genet. 163 257-275. 

Locker J., Rabinowitz M., Getz G.S. (1974). Tandem inverted repeats in mitochondrial DNA of petite mutants of Saccharomyces cerevisiae. Proc. Natl. Acad. Sci. USA 71 1366-1370. 

Nagley P. and Linnane A.W. (1970). Mitochondrial DNA deficient petite mutants of yeast. Biochem. Biophys. Res. Commun. 39 989-996. 

Rayko E., Goursot R., Cherif-Zahar B., Melis R., Bernardi G. (1988). Regions flanking on sequences affect the replication efficiency of the mitochondrial genome of ori + petite mutants from yeast. Gene 63 213-226. 

The formation of off-flavours in beer has been reviewed [40], Autoxidation of the lipids present in beer produces carbonyl compounds with very low taste thresholds. In particular, linoleic acid is oxidized to trihydroxyoctadecenoic acids (Table 22.7) which break down into 2-/mAz.y-nonenal. This aldehyde and related compounds impart a cardboard flavour to beer at very low concentrations. Other carbonyl are formed from the lipids in beer by irradiation with light including the C9, Cjo, and Cu-alka-2,4-dienals (thresholds 0 5, 0 3 and 0 01 ppb respectively) [40]. The level of diacetyl and pentane-2,3-dione in a range of commercial beers is given in Table 22.11. Quantities in excess of 0 15 ppm impart a buttery flavour more noticeable in lagers than in ales. Bacterial contamination and petite mutants of yeast result in high levels of diacetyl. The sulphur compounds characterized in beer are listed in Table 22.19 with some threshold data. Dimethyl sulphide is the major volatile... 

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