scholarly journals Mutational analysis of the Drosophila miniature-dusky (m-dy) locus: effects on cell size and circadian rhythms.

Genetics ◽  
1991 ◽  
Vol 128 (3) ◽  
pp. 571-582
Author(s):  
L M Newby ◽  
L White ◽  
S M DiBartolomeis ◽  
B J Walker ◽  
H B Dowse ◽  
...  
Keyword(s):  
Cell Size ◽  
Mutational Analysis ◽  
Genetic Characterization ◽  
Wing Development ◽  
Direct Visualization ◽  
Wild Type ◽  
Genetic Studies ◽  
Single Complex ◽  
And Behavior

Abstract A mutational analysis has been performed to explore the function of the Drosophila melanogaster miniature-dusky (m-dy) locus. Mutations at this locus affect wing development, fertility and behavior. The genetic characterization of 13 different mutations suggests that m and dy variants are alleles of a single complex gene. All of these mutations alter wing size, apparently by reducing the volume of individual epidermal cells of the developing wing. In m mutants, epidermal cell boundaries persist in the mature wing, whereas they normally degenerate 1-2 hr after eclosion in wild-type or dy flies. This has permitted the direct visualization of cell size differences among several m mutants. Mutations at the m-dy locus also affect behavioral processes. Three out of nine dy alleles (dyn1, dyn3 and dyn4) lengthen the circadian period of the activity and eclosion rhythms by approximately 1.5 hr. In contrast, m mutants have normal circadian periods, but an abnormally large percentage of individuals express aperiodic bouts of activity. These behavior genetic studies also indicate that an existing "rhythm" mutation known as Andante is an allele of the m-dy locus. The differential effects of certain m-dy mutations on wing and behavioral phenotypes suggest that separable domains of function exist within this locus.

scholarly journals Complete Genome Sequences of Six Measles Virus Strains

2018 ◽  
Vol 6 (13) ◽  
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.

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

2002 ◽  
Vol 184 (22) ◽  
pp. 6130-6137 ◽  
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.

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

2003 ◽  
Vol 69 (12) ◽  
pp. 7563-7566 ◽  
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.

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

1994 ◽  
Vol 40 (3) ◽  
pp. 208-215 ◽  
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.

scholarly journals Isolation and Characterization of Mutations in theEscherichia coli Regulatory Protein XapR

1999 ◽  
Vol 181 (14) ◽  
pp. 4397-4403 ◽  
Author(s):  
Casper Jørgensen ◽  
Gert Dandanell
Keyword(s):  
Amino Acids ◽  
Purine Nucleoside Phosphorylase ◽  
Mutational Analysis ◽  
Regulatory Protein ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Wild Type ◽  
Isolation And Characterization ◽  
In The Wild

ABSTRACT In this work, the LysR-type protein XapR has been subjected to a mutational analysis. XapR regulates the expression of xanthosine phosphorylase (XapA), a purine nucleoside phosphorylase inEscherichia coli. In the wild type, full expression of XapA requires both a functional XapR protein and the inducer xanthosine. Here we show that deoxyinosine can also function as an inducer in the wild type, although not to the same extent as xanthosine. We have isolated and characterized in detail the mutants that can be induced by other nucleosides as well as xanthosine. Sequencing of the mutants has revealed that two regions in XapR are important for correct interactions between the inducer and XapR. One region is defined by amino acids 104 and 132, and the other region, containing most of the isolated mutations, is found between amino acids 203 and 210. These regions, when modelled into the three-dimensional structure of CysB from Klebsiella aerogenes, are placed close together and are most probably directly involved in binding the inducer xanthosine.

Genetic characterization of wild-type measles viruses in Cambodia

2003 ◽  
Vol 97 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Srey Viseth Horm ◽  
Céline Dumas ◽  
Sarath Svay ◽  
Keith Feldon ◽  
Jean-Marc Reynes
Keyword(s):  
Genetic Characterization ◽  
Wild Type

scholarly journals A SUPPRESSOR OF snf1 MUTATIONS CAUSES CONSTITUTIVE HIGH-LEVEL INVERTASE SYNTHESIS IN YEAST

Genetics ◽  
1984 ◽  
Vol 107 (1) ◽  
pp. 19-32
Author(s):  
Marian Carlson ◽  
Barbara C Osmond ◽  
Lenore Neigeborn ◽  
David Botstein
Keyword(s):  
Genetic Characterization ◽  
Glucose Repression ◽  
Invertase Activity ◽  
Complementation Group ◽  
Regulatory Function ◽  
Wild Type ◽  
Suppressor Mutations ◽  
Complementation Groups ◽  
High Level

ABSTRACT The SNF1 gene product of Saccharomyces cerevisiae is required to derepress expression of many glucose-repressible genes, including the SUC2 structural gene for invertase. Strains carrying a recessive snf1 mutation are unable to ferment sucrose. We have isolated 30 partial phenotypic revertants of a snf1 mutant that were able to ferment sucrose. Genetic characterization of these revertants showed that the suppressor mutations were all recessive and defined eight complementation groups, designated ssn1 through ssn8 (suppressor of snf1). The revertants were assayed for secreted invertase activity, and although activity was detected in members of each complementation group, only the ssn6 strains contained wild-type levels. Synthesis of secreted invertase in ssn6 strains was found to be constitutive, that is, insensitive to glucose repression; moreover, the ssn6 mutations also conferred constitutivity in a wild-type (SNF1) genetic background and are, therefore, not merely suppressors of snf1. Pleiotropic defects were observed in ssn6 mutants. Genetic analysis suggested that the ssn6 mutations are allelic to the cyc8 mutation isolated by R. J. Rothstein and F. Sherman, which causes increased production of iso-2-cytochrome c. The data suggest a regulatory function for SSN6.

scholarly journals Raman Characterization of Fungal DHN and DOPA Melanin Biosynthesis Pathways

2021 ◽  
Vol 7 (10) ◽  
pp. 841
Author(s):  
Benjamin D. Strycker ◽  
Zehua Han ◽  
Aysan Bahari ◽  
Tuyetnhu Pham ◽  
Xiaorong Lin ◽  
...  
Keyword(s):  
Mutational Analysis ◽  
Wild Type ◽  
Melanin Biosynthesis ◽  
Composition And Structure ◽  
Raman Spectral Data ◽  
Dopa Melanin ◽  
Inhibition Studies ◽  
Raman Spectral ◽  
Fungal Melanins

Fungal melanins represent a resource for important breakthroughs in industry and medicine, but the characterization of their composition, synthesis, and structure is not well understood. Raman spectroscopy is a powerful tool for the elucidation of molecular composition and structure. In this work, we characterize the Raman spectra of wild-type Aspergillus fumigatus and Cryptococcus neoformans and their melanin biosynthetic mutants and provide a rough “map” of the DHN (A. fumigatus) and DOPA (C. neoformans) melanin biosynthetic pathways. We compare this map to the Raman spectral data of Aspergillus nidulans wild-type and melanin biosynthetic mutants obtained from a previous study. We find that the fully polymerized A. nidulans melanin cannot be classified according to the DOPA pathway; nor can it be solely classified according to the DHN pathway, consistent with mutational analysis and chemical inhibition studies. Our approach points the way forward for an increased understanding of, and methodology for, investigating fungal melanins.

scholarly journals Clinicopathologic and genetic characterization of nonacute NPM1-mutated myeloid neoplasms

2019 ◽  
Vol 3 (9) ◽  
pp. 1540-1545 ◽  
Author(s):  
Sanjay S. Patel ◽  
Caleb Ho ◽  
Ryan N. Ptashkin ◽  
Sam Sadigh ◽  
Adam Bagg ◽  
...  
Keyword(s):  
Genetic Characterization ◽  
Wild Type ◽  
Myeloid Neoplasms ◽  
Key Points

Key Points Nonacute NPM1-mutated myeloid neoplasms are biologically distinct from nonacute NPM1 wild-type myeloid neoplasms. Nonacute NPM1-mutated myeloid neoplasms are associated with poorer survival compared with NPM1-mutated AML and NPM1-WT myeloid neoplasms.

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

Genetics ◽  
1978 ◽  
Vol 90 (3) ◽  
pp. 463-474
Author(s):  
Manuel Ares ◽  
Peter J Bruns
Keyword(s):  
Genetic Characterization ◽  
New Technique ◽  
Wild Type ◽  
Dominant Mutation ◽  
New Mutation ◽  
Segregation Data ◽  
A New Technique ◽  
Synergistic Relationship ◽  
Lethal Doses

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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