Yu Fu - AG Schubert

During plant development, organ formation is not restricted to embryogenesis but occurs continuously from stem cell niches that are organized in different meristems, including shoot meristems, floral meristems and root meristems. Although those stem cells are all pluripotent as they are able to self-renew and to produce differentiated cells, they maintain distinct cell identities in different meristems.

Epigenetic gene regulation is an important mechanism for the maintenance of cell fate. Studies in human and mouse cells have indicated that stem cells regulate their pluripotent status by subjecting repressive histone modifications on important regulatory genes. In plants, loss of function of Polycomb group (Pc-G) proteins that catalyse the repressive mark histone 3 lysine 27 tri-methylation (H3K27me3) cause strong defects in cell identity.

So far it is largely unresolved whether maintenance of stem cells also relies on epigenetic modifications in plants. To reveal the target genes of epigenetic gene regulation in stem cells we are marking and isolating stem cells with the INTACT method1 and perform chromatin immune-precipitation (ChIP) using antibodies against histone modifications. Interestingly, we found CLAVATA 3 (CLV3), a gene expressed in stem cells is targeted by both the repressive mark H3K27me3 and the active mark H3K4me3 in stem cells, while CLV3 is only targeted by the repressive mark H3K27me3 in differentiated cells. To explore whether Pc-G target genes are generally bivalently marked in stem cells and reveal if this may keep stem cells in an undifferentiated state, we are establishing ChIP-seq analysis. Furthermore, to discover the involvement of the histone modifications in maintaining changes during the floral transition, we will compare histone modification profiles in stem cells from different developmental stages, including stem cells from the vegetative shoot apical meristem, the inflorescence meristem and from floral meristems.

Starting date: 20.10.2012 / PhD student

Thesis committee members: Daniel Schubert, Andreas Weber, Rüdiger Simon, Franziska Turck (MPI Cologne)

Mini Academic CV:

  • 2011:
    • Internship in Institut de Biologie Moléculaire des Plantes du CNRS France, Internship thesis title: The regulation of CDKA;1 in Arabidopsis by Tyrosine-4 phosphorylation, a newly discovered mechanism in human CDK1
  • 2010:
    • Master of Science in Wageningen University, the Netherlands. Thesis title: Analysis of a swi like Arabidopsis mutant, ms86
Responsible for the content: E-MailDr. Petra Fackendahl