A paramutation occurs when a silenced allele is able to communicate, and affect meiotically heritable expression of separate alleles for that loci. This means that newly silenced DNA sequences can communicate and effect expression states in subsequent generations. This means that paramutation plays a role in epigenetic gene expression.
The term "paramutation" was first used in the 1950s by Alexander Brink. Brink used the term to describe the phenomena at the r1 locus in maize. The phenomena was termed "paramutation" because the frequency of the change was nearly 100%, and the stability of the change was less than that of normal mutations. The r1 locus in maize was a premium locus to study, because all known alleles exhibit some role in paramutations. That is to say that all known alleles either induce, are affected by, or reverse paramutation.
Another example of paramutation can be viewed in mice. Mice with the allele for a white tipped tail will pass on their mRNA into offspring. Even if the offsprings genotype is wildtypee the offspring will still produce the white tipped tail, as seen in Figure 1. This aberrant mRNA is meiotically heritable and is seen in subsequent generations.
Chandler, Vicki, and Mary Alleman. "Paramutation: Epigenetic Instruction Passed Across Generations." Www.genetics.org. Genetics Society of America, Apr. 2008. Web. 03 Sept. 2014. <http://www.genetics.org/content/178/4/1839.short>.
"Paramutation." Wikipedia. Wikimedia Foundation, 24 Aug. 2014. Web. 03 Sept. 2014. <http://en.wikipedia.org/wiki/Paramutation>.
Soloway, Paul D. "Genetics: Paramutable Possibilities." Nature.com. Nature Publishing Group, 24 May 2006. Web. 03 Sept. 2014. <http://www.nature.com/nature/journal/v441/n7092/fig_tab/441413a_F1.html>.
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