Escherichia coli genetic markers

Staub, J.M. and Maliga, R. (1995). Marker rescue from the Nicotiana tabacum plastid genome using a plastid Escherichia coli shuttle vector. Mol. Gen. Genet. 249 37 2. 

The Culture Collection of the Institute of Biophysics of the Siberian Branch of the Russian Academy of Sciences (acronym CCIBSO, wdcm 836) is a unique collection. It consists of about 700 strains of luminous bacteria with specific properties and which have been isolated from different regions of the World Ocean.They are mesophiles and psychrophiles, free-living and associated with various marine inhabitants. CC IBSO deposits also genetically modified Escherichia coli strains with marker Zicc-gene. 

Fig. 3 Formation of acetylornithinase in Escherichia coli under various regulatory conditions. Plots I and 2 represent formation of the enzyme in the wild-type strain W cultivated without or with added L-arginine hydrochloride (0.2 mg/ml), respectively. Plot 3 represents the formation of the enzyme in the argR mutant W2D (which has an incidental pro marker and is grown in the presence of L-proline, 0.1 mg/ml). Enzyme and total-protein concentrations are expressed per milliliter of extract (1 ml corresponding to 7.5 ml of original culture). The slopes of the plots are the so-called diflFerential rates of enzyme synthesis indicating partial repression (7), full repression (2), and genetic derepression (i).

Chlamydomonas reinhardi is sensitive to the protein synthesis inhibitor, erythromycin. At the time, some erythromycin-resistant strains had been isolated and described, and we were considering experimental approaches to locate the sites of structural genes for proteins of plastid ribosomes. It seemed reasonable to use erythromycin resistance as a genetic marker if we could be certain that the antibiotic interacts with some part of the chloroplast ribosome and was not lethal for some other reason. Erythromycin was known to bind to the large subunit of Escherichia coli ribosomes, and the alteration leading to resistance in the bacteria was found to reside in a single protein in the 50 S subunit. ... 

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