Abstract

Gene silencing events can distort meiotically heritable epigenetic responses by altering gene expression without involving changes in DNA sequences. Paramutation is such a gene silencing process, found across kingdoms, that involves the trans silencing of an active (paramutable) allele caused by a silent (paramutagenic) allele. The silent-state of the paramutable allele is heritable and this allele can become paramutagenic in subsequent generations thereby altering Mendelian patterns of inheritance. The establishment and maintenance of paramutation has been explained by models invoking small RNA (sRNA) mediated silencing and/or chromatin structure modifications that facilitate the transfer of the epigenetic mark.

This talk will address a particular case of paramutation, the sulfurea (sulf) allele, which is a silent and paramutagenic epigenetic variant of a tomato (Solanum lycopersicum cv Lukullus) gene involved in chlorophyll synthesis. Using genetic analysis, sRNA sequencing, chromatin conformation capture (HiC/4C) in chlorotic leave tissues, I will discuss the molecular mechanism underlying paramutation.