To confirm this hypothesis, the viability of E. coli wild type and mutant strains on genes involved in Cd response (∆ zntA) or oxidative stress defenses (∆ trxC and ∆ soxS) was assessed after exposure to QDs.
Exponentially growing bacteria from the parental NCTC8325-4 (NCTC), and its mutant strains lacking genes involved in cell wall metabolism (see main text for details) were incubated with mCherry_PGRP-SA in 96-well plates.
Importantly, the relative copy number of the TEV plasmid decreased in deletion strains involving genes showing synthetic lethality or dosage rescue of the cdc20 mutant, whereas the relative copy number of the TEV plasmid increased in deletion strains involving genes showing synthetic rescue, phenotypic suppression, and dosage lethality of the cdc20 mutant.
Mutant strain construction also involved the use of the high frequency general transducing mutant of bacteriophage P22 (HT105/1 int-201) [ 53], and standard genetic techniques.> -wrap-foot> aMudJ refers to the Mud1734 transposon [ 1]. bpCA24N- carB is from the ASKA collection of Escherichia coli clones [ 4].
While they can be adapted to handle growth phenotypes of knockout mutant strains, they do not involve the gene-reaction association component of the model, which is shown here to be the main area of model improvement.
dhhc-1 and - 14 also showed a decrease in time to 90% mortality which was also seen with their mutant strains, suggesting they may be involved in processes at older age.
Complete loss of ceh-63 expression from DVC in only half the individuals of ceh-14 mutant strains suggests CEH-14 is involved in ceh-63 activation but alternative, unreliable routes to weak ceh-63 activation are also operational.
The deletion mutant strains of MNN10, ANP1 and VIG9, involved in earlier synthesis steps of the mannan backbone for N-glycosylation, showed both reduced FVI and MVI.
Adaptive responses of M. tuberculosis have been extensively analyzed by transcriptional profiling of wild-type and mutant strains in well-characterized experimental models involving uptake of bacteria by macrophages and withdrawal of oxygen or other nutrients (Rustad et al., 2008; Rohde et al., 2012; Betts et al., 2002; Stewart et al., 2002; Deb et al., 2009).
All experiments on mutant strains were conducted at least twice, while those involving dose response curves represent the combined results from two (LH846) or three (PF670462) experiments.
