Information AboutParamutation |
| CATEGORIES ABOUT PARAMUTATION | |
| gene expression | |
| genetics | |
| epigenetics | |
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Paramutation was first discovered and studied in Maize (''Zea mays'') by R.A. Brink at the University Of Wisconsin-Madison in the 1950s . Brink noticed that specific weakly expressed alleles of the ''red1'' ''(r1)'' locus in maize, which confers red pigment to corn kernels, can heritably change specific strongly expressed alleles to a weaker expression state. The weaker expression state adopted by the changed allele is heritable and can, in turn, change the expression state of other active alleles in a process termed secondary paramutation. The weaker expression state is reversible under specific genetic conditions, suggesting that paramutation is not the result of a molecular lesion in DNA , but an Epigenetic process. Interestingly, paramutation can result in a single allele of a gene controlling a spectrum of phenotypes. At ''r1'' in maize, for example, the weaker expression state adopted by an allele following paramutation can range from completely colorless to nearly fully-colored kernels. This is an exception to the rule that Continuous Varation is controlled by many genes (see Multi-genic Traits ). Allelic interactions similar to paramutation have since been reported in other organisms, including Tomato , Pea , and Mouse . The molecular basis of paramutation is not known, however paramutation may share common mechanisms with other Epigenetic phenomena, such as Gene Silencing , Imprinting , and Transvection (genetics) . |
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