scholarly journals THE RELATIVE NUMBERS OF DIFFERENT GENES IN EXPONENTIAL MICROBIAL CULTURES

Genetics ◽  
1974 ◽  
Vol 76 (3) ◽  
pp. 401-410
Author(s):  
P R Painter
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Genetic Mapping ◽  
Frequency Analysis ◽  
Dna Hybridization ◽  
Gene Frequencies ◽  
Microbial Cultures ◽  
Replication Time ◽  
Statistical Variations ◽  
Marker Frequency

ABSTRACT It is shown that the results of the marker frequency analysis of Sueoka and Yoshikawa (1965) can be derived as very good approximations from a model where the rigid assumptions of their analysis are relaxed to take into account statistical variations in the timing of cell events. It is further shown that the expression for the amount of DNA per cell can be approximated by an elementary exponential function of the growth rate, and this result facilitates genetic mapping by DNA hybridization techniques. An analysis of recent data on gene frequencies in Escherichia coli corroborates a model of symmetric, bidirectional chromosome replication with a replication time of approximately thirty minutes.

scholarly journals Determining the Optimal Thymidine Concentration for Growing Thy−Escherichia coli Strains

1998 ◽  
Vol 180 (11) ◽  
pp. 2992-2994 ◽  
Author(s):  
Felipe Molina ◽  
Alfonso Jiménez-Sánchez ◽  
Elena C. Guzmán
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Growth Medium ◽  
Type Strain ◽  
Wild Type Strain ◽  
Wild Type ◽  
Strain Mg1655 ◽  
E Coli ◽  
Replication Time ◽  
Detectable Difference

ABSTRACT Changes of thymidine concentration in the growth medium affect the chromosome replication time of Thy− strains without at the same time causing a detectable difference in the growth rate (R. H. Pritchard and A. Zaritsky, Nature 226:126–131, 1970). Consequently, the optimal thymidine concentration cannot be determined by ascertaining which concentration produces the highest growth rate. Here we present a method for determining the optimal thymidine concentration of any Thy− Escherichia coli strain. Using this method, we found that the E. coli “wild-type” strain MG1655 has a partial Thy− phenotype.

Chromosomal mapping of Brucella abortus, strain 19

1973 ◽  
Vol 19 (1) ◽  
pp. 109-112 ◽  
Author(s):  
Robert A. Altenbern
Keyword(s):  
Frequency Analysis ◽  
Brucella Abortus ◽  
Chromosomal Mapping ◽  
Chromosomal Replication ◽  
Replication Time ◽  
Genomic Map ◽  
Marker Frequency ◽  
Duplication Time

A genomic map of Brucella abortus, strain 19, containing the relative locations of 19 genes has been derived by use of marker frequency analysis. Under the conditions used, the chromosomal replication time was approximately 60 min and the mass duplication time was 216 min.

scholarly journals Characterization and in Vivo Cloning of prlC, a Suppressor of Signal Sequence Mutations in Escherichia coli K12

Genetics ◽  
1987 ◽  
Vol 116 (4) ◽  
pp. 513-521
Author(s):  
Nancy J Trun ◽  
Thomas J Silhavy
Keyword(s):  
Escherichia Coli ◽  
Genetic Mapping ◽  
Signal Sequence ◽  
Illegitimate Recombination ◽  
Mutant Phenotype ◽  
E Coli ◽  
Physical Location ◽  
Sequence Deletion ◽  
New Alleles

ABSTRACT The prlC gene of E. coli was originally identified as an allele, prlC1, which suppresses certain signal sequence mutations in the genes for several exported proteins. We have isolated six new alleles of prlC that also confer this phenotype. These mutations can be placed into three classes based on the degree to which they suppress the lamBsignal sequence deletion, lamBs78. Genetic mapping reveals that the physical location of the mutations in prlC correlates with the strength of the suppression, suggesting that different regions of the gene can be altered to yield a suppressor phenotype. We also describe an in vivo cloning procedure using λplacMu9H. The procedure relies on transposition and illegitimate recombination to generate a specialized transducing phage that carries prlC1. This method should be applicable to any gene for which there is a mutant phenotype.

scholarly journals Role of growth rate on the orientational alignment of Escherichia coli in a slit

2017 ◽  
Vol 4 (6) ◽  
pp. 170463 ◽  
Author(s):  
Julian Sheats ◽  
Bianca Sclavi ◽  
Marco Cosentino Lagomarsino ◽  
Pietro Cicuta ◽  
Kevin D. Dorfman
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Aspect Ratio ◽  
Density Fluctuations ◽  
Global Alignment ◽  
Similar Amount ◽  
Cell Area ◽  
Nematic Ordering ◽  
Side Walls

We present experimental data on the nematic alignment of Escherichia coli bacteria confined in a slit, with an emphasis on the effect of growth rate and corresponding changes in cell aspect ratio. Global alignment with the channel walls arises from the combination of local nematic ordering of nearby cells, induced by cell division and the elongated shape of the cells, and the preferential orientation of cells proximate to the side walls of the slit. Decreasing the growth rate leads to a decrease in alignment with the walls, which is attributed primarily to effects of changing cell aspect ratio rather than changes in the variance in cell area. Decreasing confinement also reduces the degree of alignment by a similar amount as a decrease in the growth rate, but the distribution of the degree of alignment differs. The onset of alignment with the channel walls is coincident with the slits reaching their steady-state occupancy and connected to the re-orientation of locally aligned regions with respect to the walls during density fluctuations.

Growth-rate dependent regulation of mRNA stability in Escherichia coli

Nature ◽  
1984 ◽  
Vol 312 (5989) ◽  
pp. 75-77 ◽  
Author(s):  
G. Nilsson ◽  
J. G. Belasco ◽  
S. N. Cohen ◽  
A. von Gabain
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Mrna Stability ◽  
Rate Dependent

scholarly journals A collection of strains containing genetically linked alternating antibiotic resistance elements for genetic mapping of Escherichia coli.

1989 ◽  
Vol 53 (1) ◽  
pp. 1-24 ◽  
Author(s):  
M Singer ◽  
T A Baker ◽  
G Schnitzler ◽  
S M Deischel ◽  
M Goel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Genetic Mapping
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