scholarly journals Difference in sequences of the Streptomyces globisporus 1912 and 2 its mutants

2020 ◽  
Vol 26 ◽  
pp. 311-315
Author(s):  
L. V. Polishchuk
Keyword(s):  
Dna Sequences ◽  
Genetic Basis ◽  
Wild Type Strain ◽  
Original Strain ◽  
Wild Type ◽  
Phenotypic Characteristics ◽  
Homologous Sequences ◽  
Blast Analysis ◽  
Query Cover ◽  
Cluster Gene

Aim. The wild-type strain Streptomyces globisporus 1912 was isolated in 1967 from a sample of farmland (Armenia). Two mutants with different phenotypic characteristics were obtained (1912-2 and 1912-4Crt). The nucleotide sequences of 19 genes of the original strain and up to 90% of the genome sequence of its 2 mutants were determined. The aim of the study was to identify differences in the identified sequences of genomic DNA contigs of 2 mutants and individual genes of the original strain. Methods. BLASTN programs were used when comparing the DNA sequences. Results. BLAST analyzes of the sequences of 2 mutants S. globisporus (1912-2 and 1912-4Crt) revealed that they were identical (99.99%). Query cover of homologous sequences of mutants 1912-4Crt and 1912-4Crt was 95%. It was found that a number of mutant contigs (both 1912-2 and 1912-4Crt) were unique - their sequences were completely dissimilar to the sequences contigs of another variant. Conclusions. The determined sequences of genomes of 3 cultures will be useful in the construction of the genetic map of S. globisporus 1912. In addition, the comparative analysis of sequences of mutants can reveal the genetic basis of phenotypic changes. Keywords: BLAST analysis, sequences, genome, cluster, gene, identity, overlap.

scholarly journals Mutagenesis development of actinoplanes sp. KCTC 9161 by N-methyl-N'-nitro-N-nitrosoguanidine (NTG) and screening for acarbose production

2018 ◽  
Vol 14 (4) ◽  
pp. 753-760
Author(s):  
Do Thi Tuyen ◽  
Nguyen The Duong ◽  
Le Thanh Hoang
Keyword(s):  
Type Ii Diabetes ◽  
Wild Type Strain ◽  
Fermentation Medium ◽  
Original Strain ◽  
Wild Type ◽  
Chromatography Method ◽  
Mutant Strains ◽  
Insulin Dependent ◽  
Mutant Lines ◽  
Layer Chromatography

Acarbose has been widely used in the therapy of type II diabetes (non-insulin dependent) because it controls blood sugar contents of patients after meals. Acarbose, a pseudo-oligosaccharide, acts as a competitive -glucosidase inhibitor. Acarbose is produced by the strains of Bacillus, Streptomyces and Actinoplanes sp. The aim of this study was to develop mutagenesis for an Actinoplanes sp. strain and screening for acarbose production. The spores of Actinoplanes sp. KCTC 9161 strain were subjected to be mutated by N-methyl-N'-nitro-N-nitrosoguanidine (NTG) for screening and finding mutant strains that were capable of production of higher acarbose (an inhibitor of α-glucosidase) higher than wild type strain. Firstly, the original NTG solution was prepared in phosphate buffer 0.05 M, pH 6.9 and the safety concentration of NTG was determined at 5 mg/ml. Then, the spores were incubated with different NTG amounts and duration. The living colonies were transferred to fermentation medium. The results obtained showed that 15 mutant strains were produced higher acarbose than wild type when used thin layer chromatography method for analysis and comparing with standard acarbose (Sigma). Three cell lines among total tested 15 mutant lines of Actinoplanes sp. KCTC 9161 produced acarbose at a higher level or indicated a higher inhibitory activity toward α-glucosidase than the original strain. Enzymatic inhibitory ativity of α-glucosidase of three mutant strains (Actinoplanes sp. KCTC- L4, L11, L14) was increased 1.3 fold higher than wild type and Actinoplanes sp. KCTC spores were very sensitive to NTG toxic, 98% spores could not survive at the treatment condition of 50 µg NTG for 30 minutes. In addition, an applicable protocol for mutating Actinoplanes sp. using NTG was suggested for further research.

Ultrastructure and characterization of an asporogenic mutant of Clostridium botulinum type E

1973 ◽  
Vol 19 (2) ◽  
pp. 281-284 ◽  
Author(s):  
R. Z. Hawirko ◽  
K. L. Chung ◽  
A. C. Emeruwa ◽  
A. J. C. Magnusson
Keyword(s):  
Clostridium Botulinum ◽  
Wild Type Strain ◽  
Ultrastructural Changes ◽  
Wild Type ◽  
Phenotypic Characteristics ◽  
Septum Formation ◽  
Botulinum Type ◽  
Clostridium Botulinum Type E ◽  
Pathogenicity Tests

The asporogenic mutant, RSpoIIIa, showed septum formation and a nearly completed forespore about 4 h after onset of sporulation. The cells show defects at a few sites of the forespore membrane, an absence of 'germ cell wall,' and within 8 h lysis of the cytoplasm occurred indicating that the mutant was blocked at stage III. Some aberrant envelopes were seen later. Lysis of the asporogenic mutant was inhibited for up to 36 h by the addition of 2.4% glucose or sucrose to the medium and 80% of the cells showed septum formation. A comparison of the phenotypic characteristics of the asporogenic RSpoIIIa and the sporogenic MSp+ mutants, as well as the wild type, showed the same ultrastructural changes during the development of the forespore with the accumulation of intracellular iodophilic granules. In addition, the mutants showed specific immunofluorescence and precipitin lines of identity with antisera against the wild-type strain, but unlike the toxigenic wild type, the mutants were nontoxigenic by mouse pathogenicity tests.

scholarly journals Genome Shuffling Improves Degradation of the Anthropogenic Pesticide Pentachlorophenol by Sphingobium chlorophenolicum ATCC 39723

2004 ◽  
Vol 70 (4) ◽  
pp. 2391-2397 ◽  
Author(s):  
MingHua Dai ◽  
Shelley D. Copley
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Constitutive Expression ◽  
Strain Analysis ◽  
Genome Shuffling ◽  
Original Strain ◽  
Negative Bacterium ◽  
Wild Type ◽  
Enhanced Resistance ◽  
Sphingobium Chlorophenolicum

ABSTRACT Pentachlorophenol (PCP), a highly toxic anthropogenic pesticide, can be mineralized by Sphingobium chlorophenolicum, a gram-negative bacterium isolated from PCP-contaminated soil. However, degradation of PCP is slow and S. chlorophenolicum cannot tolerate high levels of PCP. We have used genome shuffling to improve the degradation of PCP by S. chlorophenolicum. We have obtained several strains that degrade PCP faster and tolerate higher levels of PCP than the wild-type strain. Several strains obtained after the third round of shuffling can grow on one-quarter-strength tryptic soy broth plates containing 6 to 8 mM PCP, while the original strain cannot grow in the presence of PCP at concentrations higher than 0.6 mM. Some of the mutants are able to completely degrade 3 mM PCP in one-quarter-strength tryptic soy broth, whereas no degradation can be achieved by the wild-type strain. Analysis of several improved strains suggests that the improved phenotypes are due to various combinations of mutations leading to an enhanced growth rate, constitutive expression of the PCP degradation genes, and enhanced resistance to the toxicity of PCP and its metabolites.

scholarly journals Characterization of γ-Butyrolactone Autoregulatory Signaling Gene Homologs in the Angucyclinone Polyketide WS5995B Producer Streptomyces acidiscabies

2009 ◽  
Vol 191 (15) ◽  
pp. 4786-4797 ◽  
Author(s):  
Frank G. Healy ◽  
Kevin P. Eaton ◽  
Prajit Limsirichai ◽  
Joel F. Aldrich ◽  
Alaina K. Plowman ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Type Strain ◽  
Wild Type Strain ◽  
Morphological Differentiation ◽  
Pcr Analysis ◽  
Wild Type ◽  
Reverse Transcription Pcr ◽  
Morphological Defects ◽  
In The Wild ◽  
Streptomyces Acidiscabies

ABSTRACT Organisms belonging to the genus Streptomyces produce numerous important secondary metabolites and undergo a sophisticated morphological differentiation program. In many instances these processes are under the control of γ-butyrolactone (GBL) autoregulatory systems. Streptomyces acidiscabies strain 84.104 produces the secondary metabolite aromatic angucyclinone polyketide WS5995B. In order to explore the role of GBL regulatory circuitry in WS5995B production and morphogenesis in S. acidiscabies, a gene cluster encoding GBL autoregulatory signaling homologs was identified and characterized. Two GBL receptor homologs, sabR and sabS, were found flanking a GBL synthase homolog sabA. Strains carrying mutations in sabS produced elevated levels of WS5995B and displayed conditional morphological defects reminiscent of defects seen in Streptomyces bldA mutants. Notably, sabS possesses a TTA codon predicted to be recognized by tRNAleu. sabA mutants produced higher levels of WS5995B than the wild-type strain but to a lesser extent than the levels of WS5995B seen in sabS mutants. Purified recombinant SabR and SabS were tested for their abilities to bind predicted AT-rich autoregulatory element (ARE) boxes within the sabRAS region. SabS did not bind any DNA sequences in this region, while SabR bound an ARE box in the region upstream of sabS. Quantitative reverse transcription-PCR analysis revealed higher levels of sabS transcript in sabR mutants than in the wild-type strain, suggesting that sabS expression is repressed by SabR. Based on these data, we propose that the S. acidiscabies sabRAS genes encode components of a signaling pathway which participates in the regulation of WS5995B production and morphogenesis.

Assessment of the field performance of compound chromosome strains compared to laboratory-reared wild-type strains in Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae)

1985 ◽  
Vol 75 (2) ◽  
pp. 233-244 ◽  
Author(s):  
P. H. Smith ◽  
R. Morton
Keyword(s):  
Type Strain ◽  
Selection Pressure ◽  
Wild Type Strain ◽  
Genetic Material ◽  
Field Performance ◽  
Lucilia Cuprina ◽  
Original Strain ◽  
Wild Type ◽  
Similar Performance ◽  
Type Strains

AbstractAn assay based on recovery rates of released laboratory-reared flies was used to compare the field performance in Australia of a series of strains bearing compound chromosomes with that of wild-type strains of Lucilia cuprina (Wiedemann). The compound chromosome strains tested all performed less well than the wild-type strains. Four of the former were recovered on average 0·37 times as readily as the average wild-type strain, and one was recovered 0·65 times as readily. The compound chromosome strains differed in the selection pressure they had been exposed to in the field, which had selected among the various compound chromosomes in an original strain and in the extent to which their non-compound chromosomes had been replaced by recently collected field material. The strain that performed best had been exposed to the most severe selection pressure, overwintering in the field, and had had much of its non-compound genome replaced. Among the group of strains with similar performance, some had had their non-compound genome replaced with field genetic material.

scholarly journals Chromatin Structure and “DNA Sequence View”: The Role of Satellite DNA in Ectopic Pairing of the Drosophila X Polytene Chromosome

2021 ◽  
Vol 22 (16) ◽  
pp. 8713
Author(s):  
Aleksandr V. Zhuravlev ◽  
Gennadii A. Zakharov ◽  
Ekaterina V. Anufrieva ◽  
Anna V. Medvedeva ◽  
Ekaterina A. Nikitina ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Dna Sequences ◽  
Wild Type Strain ◽  
3D Structure ◽  
Polytene Chromosomes ◽  
Wild Type ◽  
Analysis Software ◽  
Drosophila Model ◽  
Ectopic Pairing

Chromatin 3D structure plays a crucial role in regulation of gene activity. Previous studies have envisioned spatial contact formations between chromatin domains with different epigenetic properties, protein compositions and transcription activity. This leaves specific DNA sequences that affect chromosome interactions. The Drosophila melanogaster polytene chromosomes are involved in non-allelic ectopic pairing. The mutant strain agnts3, a Drosophila model for Williams–Beuren syndrome, has an increased frequency of ectopic contacts (FEC) compared to the wild-type strain Canton-S (CS). Ectopic pairing can be mediated by some specific DNA sequences. In this study, using our Homology Segment Analysis software, we estimated the correlation between FEC and frequency of short matching DNA fragments (FMF) for all sections of the X chromosome of Drosophila CS and agnts3 strains. With fragment lengths of 50 nucleotides (nt), CS showed a specific FEC–FMF correlation for 20% of the sections involved in ectopic contacts. The correlation was unspecific in agnts3, which may indicate the alternative epigenetic mechanisms affecting FEC in the mutant strain. Most of the fragments that specifically contributed to FMF were related to 1.688 or 372-bp middle repeats. Thus, middle repetitive DNA may serve as an organizer of ectopic pairing.

scholarly journals Regulation of Expression of GLT1, the Gene Encoding Glutamate Synthase in Saccharomyces cerevisiae

1998 ◽  
Vol 180 (14) ◽  
pp. 3533-3540 ◽  
Author(s):  
Lourdes Valenzuela ◽  
Paola Ballario ◽  
Cristina Aranda ◽  
Patrizia Filetici ◽  
Alicia González
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Regulation ◽  
Dna Sequences ◽  
Transcriptional Activation ◽  
Type Strain ◽  
Wild Type Strain ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Wild Type ◽  
Regulation Of Expression

ABSTRACT Saccharomyces cerevisiae glutamate synthase (GOGAT) is an oligomeric enzyme composed of three 199-kDa identical subunits encoded by GLT1. In this work, we analyzed GLT1transcriptional regulation. GLT1-lacZ fusions were prepared and GLT1 expression was determined in a GDH1wild-type strain and in a gdh1 mutant derivative grown in the presence of various nitrogen sources. Null mutants impaired inGCN4, GLN3, GAT1/NIL1, orUGA43/DAL80 were transformed with a GLT1-lacZfusion to determine whether the above-mentioned transcriptional factors had a role in GLT1 expression. A collection of increasingly larger 5′ deletion derivatives of the GLT1 promoter was constructed to identify DNA sequences that could be involved inGLT1 transcriptional regulation. The effect of the lack ofGCN4, GLN3, or GAT1/NIL1 was also tested in the pertinent 5′ deletion derivatives. Our results indicate that (i) GLT1 expression is negatively modulated by glutamate-mediated repression and positively regulated by Gln3p- and Gcn4p-dependent transcriptional activation; (ii) twocis-acting elements, a CGGN15CCG palindrome and an imperfect poly(dA-dT), are present and could play a role inGLT1 transcriptional activation; and (iii) GLT1expression is moderately regulated by GCN4 under amino acid deprivation. Our results suggest that in a wild-type strain grown on ammonium, GOGAT constitutes an ancillary pathway for glutamate biosynthesis.

scholarly journals Prodiginine Production inStreptomyces coelicolorCorrelates Temporally and Spatially to Programmed Cell Death

2018 ◽  
Author(s):  
Elodie Tenconi ◽  
Matthew F. Traxler ◽  
Charline Hoebreck ◽  
Gilles P. Van Wezel ◽  
Sébastien Rigali
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Genetic Basis ◽  
Wild Type Strain ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Wild Type ◽  
Synthesis Inhibitor ◽  
Dna Damaging Agents ◽  
Spatio Temporal

AbstractProgrammed cell death (PCD) is a common feature of multicellularity and morphogenesis in bacteria. While cell death has been well documented whenStreptomycesspecies switch from vegetative (nutrition) to aerial (reproduction) growth, lethal determinants are yet to be discovered to unveil the genetic basis of PCD in mycelial bacteria. In this work we used prodiginines ofStreptomyces coelicoloras model to test the hypothesis that a bacterium uses ‘self-made’ antiproliferative DNA-damaging agents as toxins of their PCD process. Spatio-temporal visualisation of the autofluorescence of prodiginines reveals that their biosynthesis is triggered in the dying zone of the colony prior to morphological differentiation of the mycelium. A prodiginine nonproducer showed hyper-accumulation of viable filaments, with increased RNA and proteins synthesis when most of the mycelium of the wild-type strain was dead when prodiginine accumulated. Addition of a prodiginine synthesis inhibitor also strongly favoured viable over dead filaments. As self-toxicity has also been reported for other producers of DNA-damaging agents we propose that cytotoxic metabolites synthetized during the morphological transition of filamentous bacteria may be used to execute PCD.Significance StatementActinobacteria are prolific producers of compounds with antiproliferative activity, but why these bacteria synthetize metabolites with this bioactivity has so far remained a mystery. Using prodiginines (PdGs) as model system, we revealed that the spatio-temporal synthesis of these molecules correlates to cell death of the producerStreptomyces coelicolorand that inhibition of their synthesis results in hyper-accumulation of viable filaments. Since PdGs potentiate death ofS. coelicolorrecurrently prior to morphological differentiation, this is a form of programmed cell death (PCD). Hence, next to weapons in competition between organisms or signals in inter- and intra-species communications, we propose a third role for secondary metabolites i.e., elements required for self-toxicity in PCD processes.

scholarly journals Effects of Mutations of RAD50, RAD51, RAD52, and Related Genes on Illegitimate Recombination in Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 383-391 ◽  
Author(s):  
Yasumasa Tsukamoto ◽  
Jun-ichi Kato ◽  
Hideo Ikeda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Quantitative Analysis ◽  
Structural Analysis ◽  
Recombination Rate ◽  
Type Strain ◽  
Negative Selection ◽  
Wild Type Strain ◽  
Illegitimate Recombination ◽  
Wild Type ◽  
In The Wild

Abstract To examine the mechanism of illegitimate recombination in Saccharomyces cerevisiae, we have developed a plasmid system for quantitative analysis of deletion formation. A can1 cyh2 cell carrying two negative selection markers, the CAN1 and CYH2 genes, on a YCp plasmid is sensitive to canavanine and cycloheximide, but the cell becomes resistant to both drugs when the plasmid has a deletion over the CAN1 and CYH2 genes. Structural analysis of the recombinant plasmids obtained from the resistant cells showed that the plasmids had deletions at various sites of the CAN1-CYH2 region and there were only short regions of homology (1-5 bp) at the recombination junctions. The results indicated that the deletion detected in this system were formed by illegitimate recombination. Study on the effect of several rad mutations showed that the recombination rate was reduced by 30-, 10-, 10-, and 10-fold in the rad52, rad50, mre11, and xrs2 mutants, respectively, while in the rud51, 54, 55, and 57 mutants, the rate was comparable to that in the wild-type strain. The rad52 mutation did not affect length of homology at junction sites of illegitimate recombination.

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