Sentences with phrase «high mutation rates»

Recent studies, however, have suggested that allelic recombination influences the underlying mutation rate, as high mutation rates are inferred in regions of high recombination.

«Cancer cells by definition have high mutation rates and genomic instability even at the very earliest stages, so you could imagine building a virus that could destroy even the earliest lesions and be used as a prophylactic,» says O'Shea.

«Short generation times and high mutation rates associated with short lifespan and fast growth enable new species to appear at a faster rate in the tropics,» he says.

This may help explain the high mutation rate that allows the virus to escape from immune responses, says Mr. Law.

The mtDNA has a much higher mutation rate than nuclear DNA, which by itself might imperil species survival, because most DNA mutations are deleterious.

RNA viruses pose a significant public health problem worldwide because their high mutation rate allows them to escape the immune response.

This rapid, malignant metastatic formation of melanoma, was previously put down to the high mutation rate that is characteristic of melanoma, i.e. genetic changes that stimulate the growth of cancer cells.

Yet despite all the fanfare about them, these drugs rarely cure anyone, because cancer cells» high mutation rate allows them to dodge the pathway concerned.

However, the enzyme isn't something that acts once — it is chronically elevated along with HPV infection, leading to years or decades of higher mutation rates.

«Rats have a higher mutation rate [than humans], so you get these different [families] developing in Polynesia,» he says.

What we did not know was that BCC is also the cancer with the highest mutation rates.

This upper bound, which represents the highest mutation rate potentially compatible with the age of our samples, is consistent with the rate of μ = 4 × 10 − 9 per generation suggested by both Skoglund et al. 28 and Frantz et al. 12, two rates also calibrated by ancient samples.

During the mutation - selection balance period (model AP), the equilibrium frequency was higher for higher mutation rates.

CLL was an appealing model for this study because its high mutation rate in the short stretch of DNA that encodes the IG heavy chain (IGH).

Although clinical trials have collectively shown a disease control rate of approximately 45 percent using this approach in ovarian cancer, they have yet to establish selective benefit in BRCA1 / 2 - deficient cancers, which should generate stronger anti-tumor immune responses given their higher mutation rate.

Yet, this is unlikely to succeed because of the high mutation rate of this virus.

Not exact matches

@ED The only thing that is assumed to be at least more or less constant in evolutionary theory is the mutation rate of individual genes, and even that, since mutations are known, eg, to increase under higher radiation, is only true «on average, over the long run».

A few studies show an effect on DNA mutations which might explain a higher rate of miscarriage, pregnancy loss and birth defect.

«There was an unexpectedly high level of HPV16 isolate diversity among women, which was surprising given the fact that the HPV16 genome replicates use the host cell machinery and has a slow mutation rate,» Mirabello says.

«The type of inflammation seen in psoriasis is known to promote insulin resistance, and psoriasis and diabetes share similar genetic mutations suggesting a biological basis for the connection between the two conditions we found in our study,» said the study's senior author Joel M. Gelfand, MD MSCE, a professor of Dermatology and Epidemiology at Penn. «We know psoriasis is linked to higher rates of diabetes, but this is the first study to specifically examine how the severity of the disease affects a patient's risk.»

One recent study of the E. coli gut bacterium puts the rate as high as 1 beneficial mutation for every 10,000 new bacteria.

ETH researchers have now shown that the high estimated mutation rates at the start of the epidemic were due to the limited number of virus samples at the time in combination with the computer models used, which calculate the estimates using genetic data from virus samples and from underlying assumptions.

To find BRCA mutations — which are very rare — most studies have examined families with very high rates of breast and other cancer in young family members.

The study, which compared each model's success in Caucasian women with those of Asian descent (Chinese, Japanese, Filipino, Korean and Vietnamese), also raised important questions about the effect of race on cancer development: When Caucasian and Asian patients with similar family histories of breast and ovarian cancer were compared, the Asian women had higher rates of genetic mutation, although the rates of these cancers for Asians have traditionally been lower.

The rate was found to be high enough to cause mutations from one generation to the next.

When analyzed, the rate of germline, newly - formed mutations was calculated to be 1.48 new mutations for every 100 million bases, higher than that for humans, which has been reported as 0.96 to 1.2 new mutations.

Moreover, higher filaggrin mutation rates, which result in a loss of urocanic acid, correlated with higher vitamin D levels in the blood.

Patients with both high tumor mutation burden and high PDL - 1 positive status had a 75 percent response rate compared with a 16 percent response rate to immunotherapy among patients with low mutation burden and low PDL - 1.

Now scientists have uncovered what may be a secret of that versatility, at least for certain microbes: individuals with a high rate of genetic mutation, says a Report in today's issue of Science.

Melott said the uptick in radiation from muons would have been high enough to boost the mutation rate and frequency of cancer, «but not enormously.

Because older sperm tend to have more chromosomal mutations — ranging in seriousness from harmless to lethal — there is among older fathers a higher rate of kids born with certain rare tumors, neural - tube defects, congenital cataracts, and upper limb defects.

Sebat and colleagues discovered that spontaneous structural mutations occurred at a surprisingly high rate in individuals — 20 percent — and mutations in autism tended to disrupt genes.

In newborns exposed to secondhand smoke, mutations in an important gene occur at a high rate, according to a pilot study in next month's Nature Medicine.

The response rate was much higher in patients whose tumours carried mutations to genes involved in repairing DNA.

A region inside the csd gene in particular represents a hot - spot with a high evolutionary rate that, together with certain amino acid mutations, decisively contributes to the formation of new csd alleles in the flanking regions.

More importantly, the plants passed this elevated mutation rate onto their offspringat a rate two to four times higher than in the progeny of unstressed parents — even when these offspring were not challenged with UV or pathogens.

Researchers found that tumors carrying mutations in the AR and FOXA1 pathways had a significantly higher response rate, 94.1 % compared to 16.6 % in tumors without the mutations.

Notably, the de novo mutation rates in this study were higher in exonic regions regardless of the paternal age.

The observed mutation rate in coding regions seems to reflect the aggressiveness of breast cancer subtypes: lower in luminal A (0.84 mutations / Mbp) than luminal B (1.36 mutations / Mbp), higher in Her2 - enriched (2.05 mutations / Mbp) and Basal - like (1.68).

FLT3 mutations are more common in patients with normal karyotype and appear to be associated with a higher rate of relapse after conventional chemotherapy.

Cancers related to chronic mutagenic exposures, such as lung cancer (tobacco smoke) and cutaneous melanoma (UV radiation), have the highest rates of somatic mutations.

Mutation rates ten-fold higher than typical lung cancers in humans, though within three-fold of «hypermutator» tumors with mutations in DNA repair genes.

That's why it's possible to have a very high validation rate (> 90 %) for somatic mutations in solid tumors like lung cancer.

The six tumors with matched normal DNA harbored 15 somatic mutations on average (range 3 - 31), a mutation rate lower than adult GBM but higher than another pediatric brain tumor, medulloblastoma.

Contingency genes are thought to be critical to the bacterium's ability to evade the host's immune defenses because they have a high rate of mutation which helps the bacterium adapt to a wide range of host environments.

But ancient - DNA sequencing is beginning to shed some light on the issue.11 For example, by comparing a human HAR sequence with the HAR sequence of an archaic hominin, researchers can estimate if the HAR mutated before, after, or during the time period of our common ancestor.12 This approach has revealed that the rate at which HAR mutations emerged was slightly higher before we split from Neanderthals and Denisovans.3, 13 As a result, most HAR mutations are millions of years old and shared with these extinct hominins (but not with chimpanzees).

Using exome sequences from 3222 British - Pakistani individuals with high parental relatedness, we estimate a mutation rate of 1.45 ± 0.05 × 10 -LRB--8) per base pair per generation in autosomal coding sequence, with a corresponding non-crossover gene conversion rate of 8.75 ± 0.05 × 10 -LRB--6) per base pair per generation.

DT40 has with 1.3 × 10 − 5 mutations / bp / generation [14] a high and stable mutation rate at the immunoglobulin light chain locus, guaranteeing constant diversification of any gene cloned into this region.

Given that most amino acid changes are slightly deleterious [12] and assuming that most genes in the genome are relatively conserved, one would expect that regions of the genome with a low recombination rate, when compared to those with a high rate, would show i) a higher ratio of non-synonymous (amino acid replacing) to synonymous (silent) substitutions (ω) and ii) a higher degree of protein divergence (dA) due, in both cases, to the reduced effectiveness of selection against slightly deleterious mutations.

Functional genomic elements, for example, are expected to be found at higher density in genome regions with a high recombination rate where fewer slightly deleterious mutations accumulate than in areas of low recombination [13].