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- Bacillus subtilis (2)
- Gene mutations (2)
- Hot springs (2)
- Mutagenesis (2)
- Non-dividing cells (2)
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- Thermophiles (2)
- Adaptative mutagenesis (1)
- Bacillus subtilis; Drug resistance in microorganisms; Genetic transcription; Mutagenesis (1)
- Bacillus subtilis; Genetic transcription; Mutagenesis (1)
- Bacteria (1)
- Carbon fixation (1)
- Cellular mutations (1)
- Chemolithoautotrophy (1)
- Chemolithotrophs (1)
- Denitration (1)
- Extremophiles (1)
- Genetic sequencing (1)
- Genetic analysis (1)
- Genetic mutations (1)
- Great Basin (1)
- Great Boiling Spring (1)
- Heterotrophic bacteria (1)
- Nevada (1)
- Nitrate reducers (1)
- Nitrate reductase gene (narG) (1)
- Nitrogen cycle (1)
- Outer membrane proteases (1)
- Pathogens (1)
- Pyrobaculum (1)
- Shigella flexneri (1)
Articles 1 - 7 of 7
Full-Text Articles in Microbiology
Dna Secondary Structures And Their Contribution To Mutagenesis In B. Subtilis Stationary Phase Cells, Carmen Vallin, Holly Martin, Christian Ross, Ronald Yasbin, Eduardo Robleto
Dna Secondary Structures And Their Contribution To Mutagenesis In B. Subtilis Stationary Phase Cells, Carmen Vallin, Holly Martin, Christian Ross, Ronald Yasbin, Eduardo Robleto
Undergraduate Research Opportunities Program (UROP)
It is widely known and accepted that the cause of many mutations in cells are generated during the replication process of actively dividing cells, however more recent research has shown that mutations also arise in non growing conditions, a phenomenon known as stationary phase mutagenesis. Much of what is known come from studies in eukaryotic and bacterial models. It has been proposed that in non~growing cells, the process of transcription plays an important role in mutagenesis. We test the hypothesis that DNA secondary structures, formed during transcription, promote mutagenesis. The transcription-generated structures are speculated to be prone to mutations by …
Antibiotic Resistance In Bacillus Subtilis As Affected By Transcriptional Derepression And The Stringent Response, Brandon Eisinger, Ronald E. Yasbin, Eduardo A. Robleto
Antibiotic Resistance In Bacillus Subtilis As Affected By Transcriptional Derepression And The Stringent Response, Brandon Eisinger, Ronald E. Yasbin, Eduardo A. Robleto
Undergraduate Research Opportunities Program (UROP)
Bacterial cells under conditions of starvation or prolonged non-lethal selective pressures accumulate mutations in highly transcribed genes. This process is part of cellular programs to increase genetic diversity in conditions of stress, also known as stationary phase or stress-induced mutagenesis. This experiment investigated mutation frequencies for antibiotic resistance as affected by the stringent response. The stringent response is a global cellular process that initiates at the cessation of growth and mediates changes in gene expression that repress synthesis of ribosome components. We used Bacillus subtilis strains that differ in RelA proficiency. The relA gene controls the synthesis of (p)ppGpp, the …
The Role Of Rpoe In Stationary Phase Mutagenesis In Bacillus, Turquoise C. Alexander, Eduardo A. Robleto
The Role Of Rpoe In Stationary Phase Mutagenesis In Bacillus, Turquoise C. Alexander, Eduardo A. Robleto
Undergraduate Research Opportunities Program (UROP)
Stationary phase mutagenesis is a phenomenon whereby random mutations are generated in non-dividing cells. In order to understand how these mutations arise, we use Bacillus subtilis, a gram positive rod-shaped model organism. It is hypothesize that increased transcription promotes stationary phase mutagenesis in this organism. We therefore examined the role of rpoE, a gene that encodes RNA polymerase ! subunit and proposed to influence efficiency of transcription. To this end, we will first generate a strain bearing a deletion in the rpoE gene. In order to determine if this gene is important for mutagenesis, we will examine the accumulation of …
The Role Of Recn In Stationary Phase Mutagenesis In Bacillus Subtilis, Lauren E. Johnson, Katherine R. Ona, Eduardo A. Robleto, Ronald E. Yasbin
The Role Of Recn In Stationary Phase Mutagenesis In Bacillus Subtilis, Lauren E. Johnson, Katherine R. Ona, Eduardo A. Robleto, Ronald E. Yasbin
Undergraduate Research Opportunities Program (UROP)
Here, we examine mutagenic programs that are independent of growth, such aspects of the evolutionary process are novel and have been implicated in the formation of cancers in animal cells and the acquisition of antibiotic resistance in animal pathogens. Adaptive or stationary phase mutagenesis is a genetic program to in increase diversity in cells under conditions of stress whereby cells escape non-dividing conditions. Previous research has shown that recombination functions are required to generate mutations that promote growth in Escherichia coli cells starved for carbon. This project tests the hypothesis that recombination functions are required for the generation of mutations …
Exploring Diversity Of Nitrate Reducing Thermophiles In Nevada Hot Springs, Jenny Lam, Jeremy A. Dodsworth, Brian P. Hedlund
Exploring Diversity Of Nitrate Reducing Thermophiles In Nevada Hot Springs, Jenny Lam, Jeremy A. Dodsworth, Brian P. Hedlund
Undergraduate Research Opportunities Program (UROP)
High rates of denitrification have been measured in Nevada geothermal hot springs, but little is known about the thermophiles that contribute to this activity. We hypothesize that heterotrophic bacteria in the genus Thermus are the most important denitrifiers in the springs. Alternatively, other microorganisms including chemolithotrophs may also be important. To test these hypotheses, several different strategies will be used to try to enrich and isolate nitrate-reducing microorganisms. Isolates will be identified by 16S rRNA gene PCR and sequencing. Subsequently, representative isolates will be chosen for nitrate reductase gene (narG) sequencing and for studies on the kinetics of nitrate reduction …
The Regulation Of The Icsp Promoter Of Shigella Flexneri By The Virulence Factor Virb, Maria Castellanos, Dustin Harrison, Helen Wing
The Regulation Of The Icsp Promoter Of Shigella Flexneri By The Virulence Factor Virb, Maria Castellanos, Dustin Harrison, Helen Wing
Undergraduate Research Opportunities Program (UROP)
Shigella flexneri is a pathogenic bacterium that causes severe dysentery in humans commonly known as shigellosis. Shigella encodes an outer membrane protease called IcsP. The regulation of icsP expression is under direct control of a transcriptional factor called VirB, which controls the expression of many virulence genes in Shigella. Previous work has shown through deletion analysis of the icsP promoter region that sequences as far as 1368 base pairs upstream of the transcription starting site are important for the regulation of the icsP gene by VirB. However, it is still unclear whether VirB activation requires sequences within the icsP promoter …
Genomic Foundations Of Carbon Fixation In Bacteria Living In Hot Springs, Rachel K. Skinner, Brian P. Hedlund, Jeremy A. Dodsworth
Genomic Foundations Of Carbon Fixation In Bacteria Living In Hot Springs, Rachel K. Skinner, Brian P. Hedlund, Jeremy A. Dodsworth
Undergraduate Research Opportunities Program (UROP)
Photosynthesis does not occur above 73°C, so organisms living above this temperature must obtain useable carbon by some other mechanism. It is generally assumed that carbon is fixed by thermophiles through the process of chemolithoautotrophy; however, primary production has never been demonstrated to occur in hot springs >73°C. We have shown that two organisms, Thermocrinis and Pyrobaculum, make up more than 90% of the cells in an 80°C Great Basin hot spring, Great Boiling Spring. We hypothesize that these organisms fix carbon in the hot spring via the reverse tricarboxylic acid (rTCA) cycle. To test this hypothesis we will: i) …