Paramutation, in genetics, is an interaction between two alleles of a single locus, resulting in a heritable change of one allele. Paramutation is a violation of Mendelian inheritance as one allele heritably affects the other. Genetics (from the Greek genno γεννώ= give birth) is the science of genes, heredity, and the variation of organisms. ... An allele is any one of a number of alternative forms of the same gene occupying a given locus (position) on a chromosome. ... The word locus (plural loci) is Latin for place. In biology and evolutionary computation, a locus is the position of a gene (or other significant sequence) on a chromosome. ... Mendelian inheritance (or Mendelian genetics or Mendelism) is a set of primary tenets that underlie much of genetics developed by Gregor Mendel in the latter part of the 19th century. ...

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. Binomial name Zea mays L. Maize (Zea mays ssp. ... Royal Alexander Brink (September 16, 1897 - October 2, 1984), known more commonly by his initials R.A. Brink, was a Canadian born plant geneticist and plant breeder at the University of Wisconsin, Madison. ... Plaque on Bascom Hall, UW-Madison. ... // Events and trends The 1950s in Western society was marked with a sharp rise in the economy for the first time in almost 30 years and return to the 1920s-type consumer society built on credit and boom-times, as well as the height of the baby-boom from returning... 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). ... Epigenetic inheritance is the transmission of information from a cell or multicellular organism to its descendants without that information being encoded in the nucleotide sequence of the gene. ...

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). Binomial name Solanum lycopersicum L. The tomato (Solanum lycopersicum) is a plant in the Solanaceae or nightshade family, native to Peru and Mexico. ... Binomial name Pisum sativum L. A pea is the small, edible round green bean which grows in a pod on the leguminous vine Pisum sativum. ... Feral mouse A mouse is a mammal that belongs to one of numerous species of small rodents in the genus Mus and various related genera of the family Muridæ (Old World Mice). ... Epigenetic inheritance is the transmission of information from a cell or multicellular organism to its descendants without that information being encoded in the nucleotide sequence of the gene. ... Imprinting is the suppressing (or silencing) of certain genes on chromosomes, depending on which parent they were received from. ... Imprinting has different meanings in: Genetics: see imprinting (genetics) Psychology and ethology: see imprinting (psychology) In addition, the term imprint is used in publishing. ... Transvection, in genetics, is a process in which the gene regulatory sequence of one allele on a chromosome interact with the coding sequence of the allele on the homologous chromosome. ...