Abstract

Paramutation is the copying of an allele’s epigenetic state onto the other allele at the same locus. Examples of paramutation are rare in plants, and even rarer in animals. The historic sulfurea paramutation in tomato (Hagemann 1958) leads to a yellowing of the leaves, but the causal locus is still unknown. I identify a candidate gene for sulfurea through mRNA-Seq and virus-induced gene silencing. The sulfurea phenotype was generated through mutagenesis, but paramutation can also occur between natural epialleles. I describe the first natural example of paramutation in tomato at a locus termed H06 , following hybrididation of the cultivated M82 and its wild relative Solanum pennellii, which highlights the importance of the RNA silencing machinery in this process. Finally, genome-wide analysis of methylation in the introgression lines suggests that paramutation is not exceedingly rare, and could play a role in the transgressive phenotypes of hybrids.