Paramutation-like features of multiple natural epialleles in tomato

Area of Science:

• Epigenetics
• Plant Genetics
• Molecular Biology

Background:

• Paramutation is an epigenetic process that challenges Mendelian segregation.
• Understanding paramutation is limited to a few examples, often involving transgenes.

Purpose of the Study:

• To investigate paramutation-like epigenetic interactions in natural tomato epialleles.
• To determine the role of sRNA production timing and RNA-directed mechanisms in these interactions.

Main Methods:

• Utilized DNA methylation patterns in Solanum lycopersicum introgression lines to infer past paramutation.
• Scanned methylomes of tomato introgression lines for differentially methylated regions.
• Analyzed segregation patterns of methylation for candidate regions.

Main Results:

• Paramutation-like properties at the H06 locus depend on sRNA production timing and follow an RNA-directed mechanism.
• Identified thousands of candidate regions exhibiting paramutation-like behavior in tomato introgression lines.
• A subset of these regions showed non-Mendelian segregation, indicating varying paramutation-like interactions.

Conclusions:

• Paramutation-like epigenetic interactions are prevalent in natural tomato epialleles.
• These interactions exhibit variability in their timing and penetrance.