Further experiments will be needed to test if the extreme Mtz susceptibility and the poor growth conferred by these furH42 mutations stem from loss of Fur's iron-dependent activities, perhaps without much impairment of Apo-Fur activities.
However, this interpretation is complicated by the fact that some of the effects on OL survival arising from gene mutations stem from the accumulation of misfolded PLP product in the ER (Gow et al., 1998; Dhaunchak and Nave, 2007); thus multiple factors may contribute to reduced OL survival in mice harbouring mutations in the PLP gene.
Not the least of the challenges that classical music faces is the increasingly unworkable celebrity-maestro model — a twentieth-century mutation, stemming from a disproportionate emphasis on the music of prior eras.
Tony Perry, an embryologist at the University of Bath, UK, says the architecture of an early embryo makes it unlikely that an egg's genome could serve as template for the repair a mutation stemming from sperm.
Accordingly, we hypothesized that H. pylori Fur's N-terminal arm is functional, and that the appearance of the furR3I mutation stemmed from its enhancement of Mtz resistance.
The multitude of pathological phenotypes that can arise in patients carrying the A3243G mutation stems from the fact that the mutation has a generic effect on the process of translation and protein production of mitochondrial components [8].
More work is needed to determine if the mutation stems from a common founder, represents a 'weak point' in the genome which allows an increased frequency of expansions to randomly occur, or a combination of these and other factors.
Such variation stems from a high mutation rate in the interval (≥3.8 × 10−4, lower bound) and is illustrated by the detection of 11 different AZFc architectures in 47 chromosomes representing the major evolutionary branches of the Y genealogy (Repping et al., 2006).
More mechanistically, the causes of pleiotropy due to resistance mutations stem either from the fact that dealing with high levels of toxin in the environment is an energetically costly process that takes resources away from other cellular functions, or because resistance is gained via mutations that alter or disrupt enzyme function and the production of essential proteins.
Characterization of mutagenicity based directly on observed mutations across whole exomes or genomes offers several advantages over previous approaches, including that many more mutations can be detected, which provides far greater statistical power and allows the parsing of the superimposed mutation signatures stemming from several exposures.
