Editor's Summary
25 May 2006
Paramutation in mice
Paramutation, first discovered in maize in the 1950s and since found in other plants and in fungi, is an inheritance pattern that breaks the rules. Most of the time Mendel's law, which states that that gene pairs sort independently, holds sway. But paramutation is an interaction between two alleles of a single locus that results in a heritable change of one allele. Now this type of non-mendelian inheritance has been found in an animal. During studies on the Kit gene in mice, the wild-type phenotype was under-represented after a cross with null mutants. Kit+/Kit+ genotypes were in fact generated with the expected frequency, but due to paramutation, most of them still had the white-spotted mutant phenotype. The mechanism for this epigenetic (DNA independent)inheritance involves transfer of RNA between gametes and zygotes. RNA is a key player in this area: it is implicated in various types of epigenetic inheritance in plants, either as a cache of genetic information or as regulatory microRNA.
News and Views: Genetics: Paramutable possibilities
A curious genetic phenomenon allows certain genetic instructions to be passed between generations without the gene variants involved being transmitted. Some spotty mice provide clues to how this might happen.
Paul D. Soloway
doi:10.1038/441413a
Article: RNA-mediated non-mendelian inheritance of an epigenetic change in the mouse
Minoo Rassoulzadegan, Valérie Grandjean, Pierre Gounon, Stéphane Vincent, Isabelle Gillot and François Cuzin
doi:10.1038/nature04674
Abstract | Full Text | PDF (442K) | Supplementary information
