Special Seminar: Plant Single Cell Biology Search- Colette L. Picard, PhD – Postdoctoral Scholar in the Jacobsen Lab at UCLA

CSB Special Seminar: Plant Single Cell Biology Search

Colette L. Picard, PhD

Postdoctoral Scholar in the Jacobsen Lab at UCLA

TITLE:

Epigenetic control of gene expression and genome stability during germline and seed development

ABSTRACT:

DNA methylation is a highly conserved epigenetic modification that alters DNA accessibility and gene expression without affecting the DNA sequence. Although much is known about the mechanisms that deposit and remove DNA methylation in the genome, the mechanisms that function downstream of DNA methylation to influence transcription are much less clear. In plants, DNA methylation dynamics play a particularly important role in germline and seed development. Here I’ll discuss two projects examining how DNA methylation affects gene expression, first in seeds, then in pollen. In developing seeds, DNA methylation regulates imprinted expression, where an allele is preferentially expressed based on whether it was maternally or paternally inherited. We used single-nucleus RNA-sequencing to examine imprinting dynamics in endosperm at an unprecedented level of detail, revealing hints about potential regulatory mechanisms for imprinted expression. In developing pollen, a support cell undergoes epigenetic reprogramming, including active DNA methylation removal. By simultaneously profiling the transcriptomes and DNA methylomes of single developing pollen nuclei, we found that a pair of DNA methylation-binding proteins, MBD5/6, are required in this support cell to protect some loci from excessive DNA demethylation during reprogramming, in part by antagonizing the binding of another DNA methylation-binding protein, MBD7. Thus, we showed that multiple opposing mechanisms can function downstream of DNA methylation.

HOST: Shelley Lumba

LOCATION: Cell and Systems Biology, 25 Harbord Street, Suite 432

LIVESTREAM LINK: https://csb.utoronto.ca/live-stream/