Biology:Transition (genetics)
From HandWiki
Short description: DNA mutation that exchanges two nucleotides
Transition, in genetics and molecular biology, refers to a point mutation that changes a purine nucleotide to another purine (A ↔ G), or a pyrimidine nucleotide to another pyrimidine (C ↔ T). Approximately two out of three single nucleotide polymorphisms (SNPs) are transitions.[1]
Transitions can be caused by oxidative deamination and tautomerization. Although there are twice as many possible transversions, transitions appear more often in genomes,[2] possibly due to the molecular mechanisms that generate them. [3]
5-Methylcytosine is more prone to transition than unmethylated cytosine, due to spontaneous deamination. This mechanism is important because it dictates the rarity of CpG islands.
See also
References
- ↑ "Rates of transition and transversion in coding sequences since the human-rodent divergence". Genomics 20 (3): 386–96. April 1994. doi:10.1006/geno.1994.1192. PMID 8034311.
- ↑ "Genomewide comparison of DNA sequences between humans and chimpanzees". Am. J. Hum. Genet. 70 (6): 1490–7. June 2002. doi:10.1086/340787. PMID 11992255.
- ↑ Mezhzherin, S. V.; Tereshchenko, V. O. (2023-06-01). "Genetic Divergence and Evolutionary Transition/Transversion Rate Bias in the Control Region of Mitochondrial DNA of Palearctic Mice (Murinae)" (in en). Cytology and Genetics 57 (3): 213–220. doi:10.3103/S0095452723030076. ISSN 1934-9440. https://doi.org/10.3103/S0095452723030076.
External links
 |  |
