Isogenic strain

Brown DM, Upcroft JA, Dodd HN, Chen N, Upcroft P (1999) Alternative 2-keto acid oxidoreductase activities in Trichomonas vaginalis. Mol Biochem Parasitol 98 203-214 Carlier JP, Sellier N, Rager MN, Reysset G (1997) Metabolism of a 5-nitroimidazole in susceptible and resistant isogenic strain of Bacterioides fragilis. Antimicrob Agents Chemother 41 1495-1499... 

J.C. Rhodes, I. Polacheck, and K.J. Kwon-Chung, Phenoloxidase activity and virulence in isogenic strains of Cryptococcus neoformans, Infect. Immun., 36, 1175, 1982. 

Additionally, within each branch of such an experiment it makes sense to control the inter-individual variation by using isogenic strains. Indeed, the greater the genetic component of variation is, the more important it is to control it in this way if falsenegative results are to be avoided. 

While most workers report the outer membrane siderophore receptors to have molecular weights in the 75-95K range, some variation in the magnitude of these numbers may be attributed to the preparative and analytical methods as well as to the particular standards used. Since enterobactin will rapidly remove iron from ferrichrome, the transport of the latter must perforce be studied in mutants lacking the former. However, such mutants often display multiple lesions. Additionally, isogenic strains have seldom been used and variations in media and cultural conditions will further confound attempts to compare results reported from different laboratories. 

Fonzi WA, Irwin M Isogenic strain construction and gene mapping in Candida albicans. Genetics 1993 134 717-728. 

Fig. 5. Flux analysis data [12,31,32] on C3-C4 conversions in isogenic strains derived from lysine-producing C. glutamicum MH20-22B in chemostat cultures revealing a strong correlation with the L-lysine production rate. Rates are molar and expressed as % of the glucose uptake rate...

Since niche exclusion is probably essential for effective competition, a naturally-occurring INA bacterium is therefore likely to be inferior to one that is isogenic with an INA strain, except at the locus controlling INA. Chemical mutagenesis is not a satisfactory way to obtain such isogenic strains. For practical reasons it is common to use chemical mutagens at concentrations which are likely to cause multiple mutations the additional mutations which do not affect INA are likely to be undetectable in the laboratory, but affect fitness adversely in the field. The... 

G. D. Sockalingum, W. Bouheda, P. Pina, P. Allouch, R. Mandray, R. Labia, J. M. Millot and M. Manfait, ATR-FTIR spectroscopic investigation of imipenem susceptible and resistant Pseudomonas aeruginosa isogenic strains, Biochem. Biophys. Res. Commun., 1997, 232, 240-256. 

Fig. 4. Relative proportion of mitochondrial and nuclear DNA in three isogenic strains. Isolation and analysis by analytical ultracentrifugation in CsCl gradients are described in Grimes et al. Strains 2180 A and B are the haploids (of mating type a and respectively), HOH the diploid, described in the text and in Table IV. Tracings represent the actual UV scans. Sedimentation is from left to right. The peak of mitochondrial and nuclear DNA appears in that order, from left to right, in the center of the gradient the shoulder on the right of the nuclear peak is the 7-DNA.

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