We present a stochastic model for tandem duplications and point mutations that can be used to estimate relative mutation rates and the total number of mutations from a single sequence. Important parameters of the model include the probability of a point mutation and the probability of a tandem duplication of a given length. Our model indicates that if the probability of point mutations is insig...

Recently Kruglyak, Durrett, Schug, and Aquadro showed that microsatellite equilibrium distributions can result from a balance between polymerase slippage and point mutations. Here, we introduce an elaboration of their model that keeps track of all parts of a perfect repeat and a simplification that ignores point mutations. We develop a detailed mathematical theory for these models that exhibits...

Antigens that are tumor specific yet retained by tumor cells despite tumor progression offer stable and specific targets for immunologic and possibly other therapeutic interventions. Therefore, we have studied two CD4(+) T cell-recognized tumor-specific antigens that were retained during evolution of two ultraviolet-light-induced murine cancers to more aggressive growth. The antigens are riboso...

"Adaptive mutation" denotes a collection of processes in which cells respond to growth-limiting environments by producing compensatory mutants that grow well, apparently violating fundamental principles of evolution. In a well-studied model, starvation of stationary-phase lac(-)Escherichia coli cells on lactose medium induces Lac(+)revertants at higher frequencies than predicted by usual mutati...

Roth’s and Andersson’s model (12) supports the conservative neo-Darwinist precept of constant and gradual evolutionary change. They exclude the possibility that mutation rates (per base pair replicated) may be affected by environmental stress (and are thus forced to argue the unimportance of those cells with demonstrably increased mutation rates). However, their model requires that we ignore mu...

Sickle cell disease is an autosomal recessive hematological disorder resulting from a missense point mutation in the beta chain of haemoglobin molecule. This article reports case homozygous sickle adult patient with long-standing history non-healing ulcer

Microbial cells under growth-limiting stress can generate mutations by mechanisms distinct from those in rapidly growing cells. These mechanisms might be specific stress responses that increase mutation rates, potentially altering rates of evolution, or might reflect non-stress-specific processes in rare growing cells. In an Escherichia coli model system, both frameshift reversion mutations and...

Point mutations of KRAS and BRAF genes are thought to be important in carcinogenesis of colon cancer. In particular, gene instability caused by decreased expression of the hMLH1 gene, a DNA mismatch repair (MMR) gene, may be linked to the activating BRAF V600E point mutation in sporadic colon cancer. However, a consensus has not been established regarding the correlation between point mutations...

ataxia-telangiectasia (at) is an autosomal recessive disorder involving cerebellar degeneration, immunodeficiency, radiation sensitivity and cancer predisposition. the atm gene on human chromosome 11q22.3 has recently been identified as the gene responsible for ataxia-telangiectasia (at). the gene mutated in at, which has been designated as the atm gene, encodes a large protein kinase with a pi...

Mutation rates vary between species, between strains within species and between regions within a genome. What are the determinants of these forms of variation? Here, via parent-offspring sequencing of the peach we ask whether (i) woody perennials tend to have lower per unit time mutation rates compared to annuals, and (ii) hybrid strains have high mutation rates. Between a leaf from a low heter...