ISOLATION AND GENETIC CHARACTERIZATION OF A MUTATION AFFECTING RIBOSOMAL RESISTANCE TO CYCLOHEXIMIDE IN TETRAHYMENA

ABSTRACT A dominant mutation at a new locus affecting resistance to cycloheximide has been isolated by exploiting a synergistic relationship with a previously known mutation for cycloheximide resistance in Tetrahymena. The new mutation (ChxB) was induced in a line homozygous for ChxA and was recovered from that background by a new technique termed interrupted genomic exclusion. Segregation data from the interrupted genomic exclusion suggest that ChxA and ChxB are separate, linked loci showing 30% recombination. Minimal lethal doses of cycloheximide for the four possible combinations of the wild-type and mutant alleles of these two genes are: wild type 6 µg/ml, ChxA 125 µg/ml, ChxB 10 µg/ml, ChxA-ChxB 175 µg/ml.

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Complete Genome Sequences of Six Measles Virus Strains

Genome Announcements ◽

10.1128/genomea.00184-18 ◽

2018 ◽

Vol 6 (13) ◽

Cited By ~ 1

Author(s):

My V. T. Phan ◽

Claudia M. E. Schapendonk ◽

Bas B. Oude Munnink ◽

Marion P. G. Koopmans ◽

Rik L. de Swart ◽

...

Keyword(s):

Next Generation Sequencing ◽

Complete Genome ◽

Measles Virus ◽

Genetic Characterization ◽

Critical Component ◽

Wild Type ◽

Genome Sequences ◽

Virus Strains ◽

Generation Sequencing

ABSTRACT Genetic characterization of wild-type measles virus (MV) strains is a critical component of measles surveillance and molecular epidemiology. We have obtained complete genome sequences of six MV strains belonging to different genotypes, using random-primed next generation sequencing.

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Metabolic Flux in Both the Purine Mononucleotide and Histidine Biosynthetic Pathways Can Influence Synthesis of the Hydroxymethyl Pyrimidine Moiety of Thiamine in Salmonella enterica

Journal of Bacteriology ◽

10.1128/jb.184.22.6130-6137.2002 ◽

2002 ◽

Vol 184 (22) ◽

pp. 6130-6137 ◽

Cited By ~ 26

Author(s):

Shara Allen ◽

Julie L. Zilles ◽

Diana M. Downs

Keyword(s):

Metabolic Flux ◽

Genetic Characterization ◽

Molecular Genetic ◽

Thiamine Pyrophosphate ◽

Wild Type ◽

Regulatory Pathway ◽

Informational Suppressors ◽

Pyrimidine Moiety ◽

Molecular Genetic Characterization

ABSTRACT Together, the biosyntheses of histidine, purines, and thiamine pyrophosphate (TPP) contain examples of convergent, divergent, and regulatory pathway integration. Mutations in two purine biosynthetic genes (purI and purH) affect TPP biosynthesis due to flux through the purine and histidine pathways. The molecular genetic characterization of purI mutants and their respective pseudorevertants resulted in the conclusion that <1% of the wild-type activity of the PurI enzyme was sufficient for thiamine but not for purine synthesis. The respective pseudorevertants were found to be informational suppressors. In addition, it was shown that accumulation of the purine intermediate aminoimidazole carboxamide ribotide inhibits thiamine synthesis, specifically affecting the conversion of aminoimidazole ribotide to hydroxymethyl pyrimidine.

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Genetic Characterization of the Carotenoid Biosynthetic Pathway in Methylobacterium extorquens AM1 and Isolation of a Colorless Mutant

Applied and Environmental Microbiology ◽

10.1128/aem.69.12.7563-7566.2003 ◽

2003 ◽

Vol 69 (12) ◽

pp. 7563-7566 ◽

Cited By ~ 29

Author(s):

Stephen J. Van Dien ◽

Christopher J. Marx ◽

Brooke N. O'Brien ◽

Mary E. Lidstrom

Keyword(s):

Biosynthetic Pathway ◽

Genetic Characterization ◽

Carotenoid Biosynthesis ◽

Biosynthesis Pathway ◽

Wild Type ◽

Methylobacterium Extorquens ◽

Growth Properties ◽

Carotenoid Biosynthesis Pathway ◽

Free Strain

ABSTRACT Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, resulting in a pigment-free strain with wild-type growth properties useful as a tool for future experiments.

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A New Technique for Characterization of Low Impedance Materials at Acoustic Frequencies

Experimental Mechanics ◽

10.1007/s11340-018-0413-4 ◽

2018 ◽

Vol 58 (8) ◽

pp. 1311-1324 ◽

Cited By ~ 1

Author(s):

W. Nantasetphong ◽

Z. Jia ◽

M.A. Hasan ◽

A.V. Amirkhizi ◽

S. Nemat-Nasser

Keyword(s):

New Technique ◽

A New Technique ◽

Low Impedance Materials

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Genetic characterization of Rhizobium sp. strain TAL1145 that nodulates tree legumes

Canadian Journal of Microbiology ◽

10.1139/m94-034 ◽

1994 ◽

Vol 40 (3) ◽

pp. 208-215 ◽

Cited By ~ 16

Author(s):

M. L. C. George ◽

J. P. W. Young ◽

D. Borthakur

Keyword(s):

Rhizobium Leguminosarum ◽

Genetic Characterization ◽

Rhizobium Meliloti ◽

Wild Type ◽

Tree Legumes ◽

Wide Range ◽

The Common ◽

Rrna Sequences ◽

Rhizobium Sp

Rhizobium sp. strain TALI 145 nodulates Leucaena ieucocephaia and Phaseolus vulgaris, in addition to a wide range of tropical tree legumes. Six overlapping clones that complemented nodulation defects in leucaena and bean rhizobia were isolated and a 40-kb map of the symbiosis region was constructed. The common nod and nifA genes were situated approximately 17 kb apart, with the nodlJ genes in between. These clones enabled a derivative of TAL1145 carrying a partially deleted pSym to form ineffective nodules on both leucaena and bean, and a similar derivative of Rhizobium etli TAL182 to form ineffective nodules on bean. When two representative clones, pUHR9 and pUHR114, were each transferred to wild-type rhizobial strains, they allowed ineffective nodulation by Rhizobium meliloti on both leucaena and bean and by Rhizobium leguminosarum bv. viciae on bean. Transconjugants of R. leguminosarum bv. trifolii formed effective nodules on leucaena and ineffective nodules on bean. Tn5 mutagenesis of the symbiosis region resulted in a variety of nodulation and fixation phenotypes on leucaena and bean. On the basis of 16S rRNA sequences, TAL1145 was found to be distinct from both R. tropici and NGR234, the two groups of leucaena symbionts that were previously described.Key words: Rhizobium, Leucaena leucocephala, nodulation, nitrogen fixation.

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Fluorescence lifetime spectroscopy: a new technique for the characterization of polyplexes

Biomedical Optics 2014 ◽

10.1364/biomed.2014.bs3a.3 ◽

2014 ◽

Author(s):

Cosimo D’Andrea ◽

Daniele Pezzoli ◽

Chiara Malloggi ◽

Alessia Candeo ◽

Alessandro Volonterio ◽

...

Keyword(s):

Fluorescence Lifetime ◽

New Technique ◽

A New Technique

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Proteomic Characterization of a Mouse Model of Familial Danish Dementia

Journal of Biomedicine and Biotechnology ◽

10.1155/2012/728178 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Monica Vitale ◽

Giovanni Renzone ◽

Shuji Matsuda ◽

Andrea Scaloni ◽

Luciano D'Adamio ◽

...

Keyword(s):

Ion Trap ◽

Scaffold Protein ◽

Synaptic Function ◽

Differentially Expressed Proteins ◽

Wild Type ◽

Dominant Mutation ◽

Immunoblotting Analysis ◽

Familial Danish Dementia ◽

Dual Specificity

A dominant mutation in theITM2B/BRI2gene causes familial Danish dementia (FDD) in humans. To model FDD in animal systems, a knock-in approach was recently implemented in mice expressing a wild-type and mutant allele, which bears the FDD-associated mutation. Since theseFDDKImice show behavioural alterations and impaired synaptic function, we characterized their synaptosomal proteome via two-dimensional differential in-gel electrophoresis. After identification by nanoliquid chromatography coupled to electrospray-linear ion trap tandem mass spectrometry, the differentially expressed proteins were classified according to their gene ontology descriptions and their predicted functional interactions. The Dlg4/Psd95 scaffold protein and additional signalling proteins, including protein phosphatases, were revealed by STRING analysis as potential players in the altered synaptic function ofFDDKImice. Immunoblotting analysis finally demonstrated the actual downregulation of the synaptosomal scaffold protein Dlg4/Psd95 and of the dual-specificity phosphatase Dusp3 in the synaptosomes ofFDDKImice.

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