DNA base sequence variability inkatF(putative sigma factor) gene ofEscherichia coli

ABSTRACT The alternate RNA polymerase sigma factor gene, sigF, which is expressed in stationary phase and under stress conditions in vitro, has been deleted in the virulent CDC1551 strain ofMycobacterium tuberculosis. The growth rate of the ΔsigF mutant was identical to that of the isogenic wild-type strain in exponential phase, although in stationary phase the mutant achieved a higher density than the wild type. The mutant showed increased susceptibility to rifampin and rifapentine. Additionally, the ΔsigF mutant displayed diminished uptake of chenodeoxycholate, and this effect was reversed by complementation with a wild-type sigF gene. No differences in short-term intracellular growth between mutant and wild-type organisms within human monocytes were observed. Similarly, the organisms did not differ in their susceptibilities to lymphocyte-mediated inhibition of intracellular growth. However, mice infected with the ΔsigF mutant showed a median time to death of 246 days compared with 161 days for wild-type strain-infected animals (P < 0.001). These data indicate that M. tuberculosis sigF is a nonessential alternate sigma factor both in axenic culture and for survival in macrophages in vitro. While the ΔsigF mutant produces a lethal infection of mice, it is less virulent than its wild-type counterpart by time-to-death analysis.

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Physical mapping of DNA base sequence homologies between an octopine and a nopaline Ti plasmid of Agrobacterium tumefaciens

Journal of Molecular Biology ◽

10.1016/0022-2836(81)90239-4 ◽

1981 ◽

Vol 152 (2) ◽

pp. 183-208 ◽

Cited By ~ 101

Author(s):

G. Engler ◽

A. Depicker ◽

R. Maenhaut ◽

R. Villarroel ◽

M. Van Montagu ◽

...

Keyword(s):

Agrobacterium Tumefaciens ◽

Physical Mapping ◽

Ti Plasmid ◽

Base Sequence ◽

Dna Base ◽

Sequence Homologies

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Expression of a Cryptic Secondary Sigma Factor Gene Unveils Natural Competence for DNA Transformation in Staphylococcus aureus

PLoS Pathogens ◽

10.1371/journal.ppat.1003003 ◽

2012 ◽

Vol 8 (11) ◽

pp. e1003003 ◽

Cited By ~ 68

Author(s):

Kazuya Morikawa ◽

Aya J. Takemura ◽

Yumiko Inose ◽

Melody Tsai ◽

Le Thuy Nguyen Thi ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Sigma Factor ◽

Dna Transformation ◽

Natural Competence ◽

Factor Gene

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DNA: Up Close and Personal

DNA Demystified ◽

10.1093/oso/9780190092962.003.0006 ◽

2020 ◽

pp. 133-157

Author(s):

Alan McHughen

Keyword(s):

Y Chromosome ◽

Dna Sequence ◽

Genetic Information ◽

Base Sequence ◽

Gold Mine ◽

Family Tree ◽

Health Issues ◽

Dna Base ◽

The Individual ◽

Cheek Swab

We now look at personal genetics and genomics, especially important with the rise of companies willing to analyze your own DNA (for a small fee, of course), giving you the raw genetic information about yourself and your ancestors. Although we previously learned that DNA is “the same” in all species, we now turn to the individual, you, and explore how your DNA base sequence differs from the DNA base sequence of a bacterium, a liverwort, a chimp, and your weird Uncle Jason. This chapter provides the background to appreciate the specific issues related to medical and health issues, and then genealogical studies, coming up in later chapters. For most people, personal genomics testing involves sending a sample of DNA, in the form of spit or a cheek swab, to a lab. What kind of analyses do the labs perform, and what information do they reveal? In addition to full DNA sequence tests, there’s a whole gamut of other DNA tests, including SNP tests, Y-chromosome tests, mtDNA tests, and more. Your DNA base sequence is a gold mine of information unique to you, and it is entirely yours to discover. Whether you are curious about your medical and health genetics, wish to connect with relatives and build a family tree, or are just fascinated at what information your ancestors provided you, these next chapters will help you dig up the hidden secrets of your own genetic heritage.

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