Location

University of Nevada Las Vegas, Science and Education Building

Start Date

9-8-2011 10:15 AM

End Date

9-8-2011 12:00 PM

Description

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 exposing regions of single stranded DNA to lesions. We examined the Bacillus subtilis gene thiF, predicted by in silica analysis to be prone to mutations at particular locations during transcription. By altering the base sequence of this gene, the stability of its stem-loop structures is affected, thereby allowing us to test whether transcription of the altered sequence influences accumulation of mutations in thiF. Our assay for detection of mutations is based on reversion to thiamine prototrophy in cells under conditions of starvation. Ultimately, these experiments will increase our understanding of how mutations occur in cells of all domains of life.

Keywords

Bacillus subtilis; Genetic transcription; Mutagenesis

Disciplines

Biochemistry | Genetics | Microbiology | Molecular Biology

Language

English

Comments

Research sponsored by: Nevada INBRE grants # MCB0843606 and #P20 RR016463


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Aug 9th, 10:15 AM Aug 9th, 12:00 PM

DNA secondary structures and their contribution to mutagenesis in B. subtilis stationary phase cells

University of Nevada Las Vegas, Science and Education Building

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 exposing regions of single stranded DNA to lesions. We examined the Bacillus subtilis gene thiF, predicted by in silica analysis to be prone to mutations at particular locations during transcription. By altering the base sequence of this gene, the stability of its stem-loop structures is affected, thereby allowing us to test whether transcription of the altered sequence influences accumulation of mutations in thiF. Our assay for detection of mutations is based on reversion to thiamine prototrophy in cells under conditions of starvation. Ultimately, these experiments will increase our understanding of how mutations occur in cells of all domains of life.