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  • direct
  • Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and direct sequencing were performed to detect mutations in codon 12 or 13 of K- ras . (ebscohost.com)
  • genetics
  • Methods to diagnose the likelihood of a patient with mutations in BRCA1 and BRCA2 getting cancer were covered by patents owned or controlled by Myriad Genetics. (wikipedia.org)
  • The distribution of fitness effects of new mutations is an important parameter in population genetics and has been the subject of extensive investigation. (wikipedia.org)
  • mutagens
  • petite mutations can be induced using a variety of mutagens, including DNA intercalating agents, as well as chemicals that can interfere with DNA synthesis in growing cells. (wikipedia.org)
  • A few common mutagens that induce mutations are: Ultraviolet light (UV)- Causes pyrimidine (T or C) nucleotide bases on the same strand to covalent join together forming a pyrimidine dimer. (wikipedia.org)
  • codon
  • In addition to the reading frame, Crick also used suppressor mutations to determine codon size. (wikipedia.org)
  • In this instance, if there was a thousand times less UCC tRNA than UCU tRNA, then the incorporation of serine into a polypeptide chain would happen a thousand times more slowly when a mutation causes the codon to change from UCU to UCC. (wikipedia.org)
  • Silent mutations lead to a change of one of the letters in the triplet code that represents a codon, but despite the single base change, the amino acid that is coded for remains unchanged or similar in biochemical properties. (wikipedia.org)
  • Stop-gain is a mutation that results in a premature termination codon (a stop was gained), which signals the end of translation. (wikipedia.org)
  • Stop-loss is a mutation in the original termination codon (a stop was lost), resulting in abnormal extension of a protein's carboxyl terminus. (wikipedia.org)
  • Start-loss is a point mutation in a transcript's AUG start codon, resulting in the reduction or elimination of protein production. (wikipedia.org)
  • gene mutation
  • When a person has two copies of the MTHFR C677T gene mutation (homozygous) or one copy of MTHFR C677T and one copy of A1298C (compound heterozygous), decreased MTHFR enzyme activity slows down the homocysteine-to-methionine conversion process and can lead to a buildup of homocysteine in the blood. (labtestsonline.org)
  • Only 5-10% of breast cancer cases in women are attributed to BRCA1 and BRCA2 mutations (with BRCA1 mutations being slightly more common than BRCA2 mutations), but the impact on women with the gene mutation is more profound. (wikipedia.org)
  • Over DNA, RNA or a single gene mutation rates are changing. (wikipedia.org)
  • majority of mutations
  • It is probably fair to estimate the frequency of a majority of mutations in higher organisms between one in ten thousand and one in a million per gene per generation. (angelfire.com)
  • Accordingly, the great majority of mutations, certainly well over 99%, are harmful in some way, as is to be expected of the effects of accidental occurrences. (angelfire.com)
  • The large majority of mutations, however, are harmful or even lethal to the individual in whom they are expressed. (angelfire.com)
  • favorable
  • The abundance of some genetic changes within the gene pool can be reduced by natural selection, while other "more favorable" mutations may accumulate and result in adaptive changes. (wikipedia.org)
  • Because of natural selection, unfavorable mutations will typically be eliminated from a population while favorable changes are generally kept for the next generation, and neutral changes accumulate at the rate they are created by mutations. (wikipedia.org)
  • mutants
  • Most petite mutants are a suppressive type, and they differ from natural petite by affecting the wild-type, although both are a mutation in mitochondrial DNA. (wikipedia.org)
  • Mutation breeding, sometimes referred to as "variation breeding", is the process of exposing seeds to chemicals or radiation in order to generate mutants with desirable traits (or lacking undesirable ones) to be bred with other cultivars. (wikipedia.org)
  • Mutants are based on well-defined mutation operators that either mimic typical programming errors (such as using the wrong operator or variable name) or force the creation of valuable tests (such as dividing each expression by zero). (wikipedia.org)
  • On the other hand, RecG mutants were key to the expression of RecA-dependent mutations, which were a major portion of study in the SOS response experiments, such as the ability to utilize lactose. (wikipedia.org)
  • small mutations
  • The man probably more responsible than any other for the modern view of evolution known as neo-Darwinism, which says evolution proceeds by the accumulation of small mutations preserved by natural selection, is even less confident in the frequency of beneficial mutations. (angelfire.com)
  • deletion
  • Researchers showed that mutations caused by either a single base insertion (+) or a single base deletion (-) could be "suppressed" or restored by a second mutation of the opposite sign, as long as the two mutations occurred in the same vicinity of the gene. (wikipedia.org)
  • This led to the conclusion that genes needed to be read in a specific " reading frame " and a single base insertion or deletion would shift the reading frame ( frameshift mutation ) in such a way that the remaining DNA would code for a different polypeptide than the one intended. (wikipedia.org)
  • Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. (wikipedia.org)
  • accumulation
  • Mutation accumulation lines have been used to characterize mutation rates with the Bateman-Mukai Method and direct sequencing of e.g. intestinal bacteria, round-worms, yeast, fruit flies, small annual plants. (wikipedia.org)
  • hereditary
  • It remains true to say that we know of no way other than random mutation by which new hereditary natural selection by which the hereditary constitution of a population changes from one generation to the next. (angelfire.com)
  • Harmful mutations in these genes may produce a hereditary breast-ovarian cancer syndrome in affected persons. (wikipedia.org)
  • Having knowledge of mutation rates is vital to understanding the future of cancers and many hereditary diseases. (wikipedia.org)
  • Mutation Research, (705), 3-10.described mutation frequency as containing a segment of cells that includes a mutation within particular trait, and the authors defined mutation rates as being chances a innovative alteration will take place in hereditary trait due to cell division. (wikipedia.org)
  • proteins
  • It was found that the reason the second amber mutation could suppress the first one is that the two numerically reduced structural proteins would now be in balance. (wikipedia.org)
  • common mutation
  • On the right, a fairly common mutation in mice causes bands in the coat around the body. (mit.edu)
  • Finally, a common mutation in humans causes red blood cells to be shaped in a sickle pattern as shown above on the upper left. (mit.edu)
  • Thymine-thymine dimers are the most common mutation caused by UV light. (wikipedia.org)
  • causes
  • However, if a second amber mutation is defective in a base plate component and causes one tenth the number of base plates to be made, this may restore the balance of tail fibers and base plates, and thus allow infective phage to be produced. (wikipedia.org)
  • Cornish and Breton have so-called mixed mutations, where a trigger causes one mutation to some sounds and another to other sounds. (wikipedia.org)
  • A K103N mutation in HIV-1 causes the hydrophobic pocket in which the NNRTI binds to inhibit enzyme activity in reverse transcriptase to close by means of a hydrogen bond. (wikipedia.org)
  • It is thought that the Swedish mutation causes early-onset Alzheimer's disease by beta-secretase cleavage within the secretory pathway. (wikipedia.org)
  • beneficial
  • The basic evolution model would predict, therefore, that mutations must be primarily beneficial, generating a 'vertical' change upward toward higher degrees of order. (angelfire.com)
  • The creation model, on the other hand, would predict that, if there are any such things as real mutations, causing 'vertical' changes in complexity and order of the kings, they will be harmful, not beneficial. (angelfire.com)
  • As a matter of fact, the phenomenon of a truly beneficial mutation, one which is known to be a mutation and not merely a latent characteristic already present in the genetic material but lacking previous opportunity for expression, and one which is permanently beneficial in the natural environment, has yet to be documented. (angelfire.com)
  • knowing whether a mutation is present in the cells can help determine if EGFR-targeted tyrosine kinase inhibitors such as gefitinib and erlotinib may be beneficial for treating the tumor. (labtestsonline.org)
  • change
  • A mutation is any change occurring in the message that a gene carries. (blackwellpublishing.com)
  • A mutation is assumed to be a real structural change in a gene, of such character that something novel is produced, not merely a reworking of something already there. (angelfire.com)
  • Mutation can result in many different types of change in sequences. (wikipedia.org)
  • If this color change is advantageous, the chance of this butterfly's surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population. (wikipedia.org)
  • Consonant mutation is change in a consonant in a word according to its morphological or syntactic environment. (wikipedia.org)
  • Conservative mutations result in an amino acid change. (wikipedia.org)
  • Cornish
  • The individual languages vary on the number of mutations available: Scottish Gaelic has one, Irish and Manx have two, Welsh has three (not counting mixed mutations) and Cornish and Breton have four (counting mixed mutations). (wikipedia.org)
  • harmful
  • Even if the mutations are not harmful enough to cause their carriers to be eliminated completely by natural selection, the over-all effect is to gradually lower the viability of the population. (angelfire.com)
  • Women with harmful mutations in either BRCA1 or BRCA2 have a risk of breast cancer that is about five times the normal risk, and a risk of ovarian cancer that is about ten to thirty times normal. (wikipedia.org)
  • nonfunctional
  • Mutations in viral reverse transcriptase can cause the enzyme to not incorporate these nonfunctional analogs, in favor for their natural counterparts. (wikipedia.org)
  • allele
  • For example, if the embryo inherits an already mutated allele from the father, and the same allele from the mother underwent an endogenous mutation, then the child will display the disease related to that mutated gene, even though only 1 parent carries the mutant allele. (wikipedia.org)
  • The cancer risk caused by BRCA1 and BRCA2 mutations are inherited in a dominant fashion even though usually only one mutated allele is directly inherited. (wikipedia.org)
  • Different genetic variants within a species are referred to as alleles, therefore a new mutation can create a new allele. (wikipedia.org)
  • result
  • These SNPs result in changes in the DNA (or mutations) that are associated with decreased MTHFR activity and increased homocysteine levels in the blood, which may increase the risk of premature cardiovascular disease (CVD) , formation of inappropriate blood clots ( thrombosis ), and stroke . (labtestsonline.org)
  • Certain mutations called "activating mutations" in the EGFR gene can result in excessive signaling for growth and uncontrolled proliferation of cancer cells. (labtestsonline.org)
  • As a result, half of the people with BRCA gene mutations are male, who would then pass the mutation on to 50% of their offspring, male or female. (wikipedia.org)
  • As a result, mutations in the viral DNA polymerase that make it resistant to these drugs are selected for, which ultimately can cause complete resistance of the treatment. (wikipedia.org)