Silent mutations or synonymous mutations are DNAmutations that, although they alter a particular codon, they do not alter the final amino acid, and hence do not affect the final protein. Space-filling model of a section of DNA molecule Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and many viruses). ... Mutations are permanent, sometimes transmissible (if the change is to a germ cell) changes to the genetic material (usually DNA or RNA) of a cell. ... RNA codons. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...
Because silent mutations do not alter protein function they are often treated as though they are evolutionarily neutral. However, many organisms are known to exhibit codon usage biases, suggesting that there is selection for the use of particular codons. In addition, analysis of mutations in genes causing genetic disorders has shown that silent mutations can affect genetranscription, leading to the formation of truncated protein with reduced or no function. In molecular cloning experiments, it can be useful to introduce silent mutations into a gene of interest in order to create or remove recognition sites for restriction enzymes. An online tool that can analyse a sequence of interest for possible mutations to create restriction sites is given in the External Links section. Charles Darwin, father of the theory of evolution by natural selection. ... Codons are triplets of nucleotides that together specify an amino acid residue in a polypeptide chain. ... Natural selection is a process by which biological populations are altered over time, as a result of the propagation of heritable traits that affect the capacity of individual organisms to survive and reproduce. ... A genetic disorder, or genetic disease is a disease caused by abnormal expression of one or more genes in a person causing a clinical phenotype. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Transcription is the process through which a DNA sequence is enzymatically copied by an RNA polymerase to produce a complementary RNA. In the case of protein-encoding DNA, transcription is the beginning of the process that ultimately leads to the translation of the genetic code (via the mRNA intermediate) into...
Chao H.K., Hsiao K.J., and Su T.S. 2001. A silent mutation induces exon skipping in the phenylalanine hydroxylase gene in phenylketonuria. Human Genetics 108(1):14-9
Monteraa, M. el al. 2001. A silent mutation in exon 14 of the APC gene is associated with exon skipping in a FAP family. Journal of Medical Genetics 38:863-867
Mutations can be caused by copying errors in the genetic material during cell division and by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can occur deliberately under cellular control during processes such as meiosis or hypermutation.
Mutations create variation in the gene pool, and the less favorable (or deleterious) mutations are removed from the gene pool by natural selection, while more favorable (beneficial or advantageous) ones tend to accumulate, resulting in evolutionary change.
One theory for the etiology of the relatively high frequency of CCR5-32 in the euopean population is that is conferred resistance to the bubonic plague in mid-14th century Europe .
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