Strategic planning for the business of community health and home care.
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Community Health Nursing↗
Biomedical subjects
M Wesolowski
Publications and source records attributed to M Wesolowski.
Two new double-stranded RNA molecules showing non-mendelian inheritance and heat inducibility in Saccharomyces cerevisiae.
Certain strains of Saccharomyces cerevisiae were found to have a complex nuclear defect (designated clo-) that makes cells unable to maintain some L-B and some L-C double-stranded RNAs at 25 degrees C. The clo- strains were not defective in maintenance of L-A, M1, or M2 double-stranded RNAs. Most clo-strains lacking L and M carry small amounts of two double-stranded RNA species intermediate in size between L and M and denoted T (2.7 kilobase pairs) and W (2.25 kilobase pairs). Some strains carry both T and W, some carry neither, and some carry only W; no strains carrying only T have been found. Both T and W show 4+:0 segregation in meiosis and efficient transmission by cytoplasmic mixing (cytoduction), indicating that they are non-Mendelian genetic elements. T and W do not cross-hybridize with each other or with L-A, L-B, L-C, M1, M2, or chromosomal DNA. T and W are apparently distinct from other known non-Mendelian genetic elements (2mu DNA, [rho], [psi], 20S RNA, [URE3]). In most strains the copy number of both T and W is increased about 10-fold by the growth of cells at 37 degrees C. This heat inducibility of T and W is under control of a cytoplasmic gene. T and W double-stranded RNAs are not found in a purified L-containing virus-like particle preparation from a strain containing L-B, T, and W double-stranded RNAs. The role, if any, of T or W in the killer systems is not known.
Genes, Fungal↗
Characterization and biosynthesis of soluble and membrane-bound carbonic anhydrase in brain.
Carbonic anhydrase from both the cytoplasmic and membrane fractions of the forebrains of rats was characterized with respect to enzymatic activity, immunoreactivity, and in vitro biosynthesis. A procedure for the rapid purification of both membrane-bound and soluble brain carbonic anhydrase is presented that permits retention of full enzymatic activity. Both forms of the enzyme were found to show specific activities of approximately 5500 Units/mg protein when CO2 hydrating activity was determined. In addition, they exhibited similar esterase activity when assayed with p-nitrophenyl acetate. The membrane-bound form, although requiring detergent for extraction from membranes, was freely soluble in aqueous buffers after purification. The molecular weights of both soluble and membrane-bound carbonic anhydrase are 30,000 daltons, and mixing experiments failed to show any significant differences with respect to size. The two forms also exhibit isoelectric points of 7.2. However, the two proteins were found to differ in two respects. Complement fixation indicated that antibodies to soluble carbonic anhydrase had a higher affinity for the soluble form than for the membrane-bound form. The failure to observe any precursor-product relationship between these two proteins with pulse chase studies and the establishment that carbonic anhydrase-like proteins are synthesized on both free polysomes and the rough endoplasmic reticulum indicated that these proteins are synthesized by two separate mechanisms. In vitro synthesis on both free and bound polysomes was determined by two independent methods using different antibodies and different analytical procedures. The basis for these findings and their physiologic importance are discussed.
Animals↗
Transformation of Kluyveromyces lactis by killer plasmid DNA.
Some strains of Kluyveromyces lactis contain two linear double-stranded DNA plasmids, k1 and k2. The presence of the two plasmids confer on the cell a "killer" character, due to the production of a toxin that kills the sensitive cells. We have used one of these linear DNA molecules as a gene vector to transform K. lactis cells. Hybrid plasmids containing parts of the k1 plasmid and the URA3 gene of Saccharomyces cerevisiae have been constructed. We have found that the hybrid plasmids were able to transform a uracil-requiring strain of K. lactis (uraA mutant) to a prototrophic form. The transformed phenotype cosegregated with the hybrid plasmids. The transforming plasmids contained the sequence of one or both ends of the linear k1 DNA, but they were integrated into a circular molecule.
Ascomycota↗
Role of nuclear genes in expression of a mitochondrial tRNA gene in Saccharomyces cerevisiae.
In yeast mitochondria, most of the isoaccepting species of tyrosyl tRNA are coded by a mitochondrial gene, tyrA. A particular isoaccepting species is coded by a second mitochondrial gene, tyrB. This gene is not expressed in certain strains of yeast which show no deficient phenotype. Genetic crosses between strains expressing or not expressing the tyrB gene demonstrate that expression is controlled by specific nuclear genes and that a mutation of the tyrA gene can be bypassed when the tyrB gene is operative.
Cell Nucleus↗
Two genes for mitochondrial tyrosine transfer RNA in yeast. Localization and expression.
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DNA, Mitochondrial↗
Linear mitochondrial deoxyribonucleic acid from the yeast Hansenula mrakii.
The mitochondrial deoxyribonucleic acid (mtDNA) from a petite-negative yeast, Hansenula mrakii, was studied. A linear restriction map was constructed with 11 restriction enzymes. The linearity of the genome was confirmed by direct end labeling of the molecule, followed by restriction analysis. The molecular weight of the DNA was found to be 55,000 base pairs. This is the first linear mtDNA found in yeast species. Using specific gene probes obtained from Saccharomyces cerevisiae mtDNA, we have constructed a gene map of H. mrakii mtDNA. The arrangement of genes in this linear genome was very different from the circular mtDNA of other known yeasts.
Chromosome Mapping↗
The genetic map of transfer RNA genes of yeast mitochondria: correction and extension.
Ninety five rho- mitochondrial DNA's of Saccharomyces cerevisiae were compared for their deletion structure by means of 15 genetic markers and 22 tRNA genes. The patterns of co-deletion and co-retention of different tRNA genes allowed us to determine their positions with respect to each other. The deduced order of tRNA genes was consistent with the order of the genetic markers established by independent genetic approaches. Our previously proposed mitochondrial tRNA gene map has been revised and extended. Transfer RNA genes, corresponding to all 20 aminoacids, and two isoacceptor tRNA genes were localized. The possible position of each tRNA gene has been indicated on the physical map of mitochondrial DNA. Seventeen tRNA genes are carried by a narrow region representing less than 20% of the wild type genome.
Chromosome Mapping↗
Two isoaccepting seryl tRNAs coded by separate mitochondrial genes in yeast.
In S. cerevisiae four isoacceptor mitochondrial tRNAs for serine have been separated by reversed phase chromatography. At least two of these species are products of different genes. In this work the deletion mapping technique has been used to locate two genes for tRNAser. The gene for tRNAser previously localized in the oli I region of the mitochondrial genome has been found to code for tRNAser2, and another gene coding for tRNAser1 has been detected in the region where most of other tRNA genes are found. Results of fine mapping experiments allowed to localize this gene in the proximity of the gene for tRNAarg.
Chromatography↗
Preferential deletion of a specific region of mitochondrial DNA in Saccharomyces cerevisiae by ethidium bromide and 3-carbethoxy-psoralen: directional retention of DNA sequence.
Grande strains of Saccharomyces cerevisiae were mutagenized either by ethidium bromide or by 3-carbethoxy-psoralen (a monofunctional furocoumarin derivative) activated by 365nm light. 973 primary rho- clones induced were randomly collected and analyzed individually for the presence or absence of fifteen mitochondrial genetic markers. 1. Under mild conditions of mutagenesis, 83% of the primary clones showed single-deletion genotypes; a unique order of 14 markers could be deduced from the patterns of the deletion. The gene order confirmed our previous map constructed from the analysis of established non-random petite clones. From the frequencies of disjunction between markers, the distance separating 14 mitochondrial markers were estimated. 2. One region, carrying oxi-3, pho-1 and mit 175 loci, was preferentially lost in rho- mutants: there is a strong constraint in the frequencies of various genotypes found in rho- clones. On each side of this particular region, a bidirectionally oriented pattern of retention of markers is observed.
Base Sequence↗
Inorganic bismuth(III) compounds in the therapy.
A survey is given of the pharmacopoeial preparations of inorganic Bi(III) compounds: bismuth subnitrate and bismuth subcarbonate. The use of these preparations, methods of preparation, qualitative and quantitative assays have been reviewed.
Animals↗