Small but dominant RNA

As Mendel observed over a century ago, the manifestation of a phenotype can crucially depend on the dominant-recessive relationship between alleles at a given locus. A study of plant self-incompatibility suggests a new mechanism by which such dominant-recessive relationships arise: in this system, a small RNA encoded by the dominant allele acts in trans to epigenetically silence the expression of the recessive allele.
A plant uses a 'self-incompatibility'mechanism to reject fertilization by pollen that is genetically too similar to itself. In Brasssica species, this trait is controlled by three tightly linked, multiallelic loci and particularly by the gene encoding the male-specific protein S locus protein 11 (SP11) and its female-specific receptor S receptor kinase SRK and SRK alleles known as the S haplotye/





Nature Reviews Genetics 11, 670-671 (October 2010) |
doi:10.1038/nrg2875