Genome-Wide Identification of Chromatin Regions Associated with SEUSS Transcriptional Adaptor During Carpel Margin Meristem Development in Arabidopsis thaliana

Undergraduate #34
Discipline: Biological Sciences
Subcategory: Plant Research

Marlyn Bernardo - North Carolina Agricultural and Technical State University
Co-Author(s): Miguel Flores and Robert Franks, North Carolina State University, Raleigh, NC

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The gynoecium is the female reproductive organ of flowering plants. In Arabidopsis thaliana a critical meristematic structure known as carpel margin meristem (CMM) develops inside the gynoecium. The CMM generates the ovules that when fertilized will developed into seeds. The molecular mechanisms that specify and support the development of the CMM and regulate its ability to generate ovules are largely unknown. Genetic evidence indicates that transcriptional regulators SEUSS (SEU) and AINTEGUMENTA (ANT) function synergistically for the proper ovule development from the CMM as it has been shown in the seu ant double mutant plants that displayed loss of ovules. Consequently, it has been proposed that both SEU and ANT proteins modulate downstream transcriptional regulators that coordinate ovule development. The purpose of this research is to optimize our Chromatin Immunoprecipitation Sequencing (ChIP-Seq) approach to identify global chromatin regions associated with SEUSS protein. This technique allows us to enrich chromatin sites bound by SEUSS protein in floral primordial of A. thaliana by using a specific anti-Green Fluorescent Protein (GFP) antibody in a transgenic line expressing GFP-tagged version of SEUSS (SEU::GFP). We routinely found an average of 1.8% recovered DNA associated with SEUSS protein in the Agamous locus. The resulting ChIPed DNA is then subjected to enrichment quantification analysis by qPCR (ChIP-qPCR) of AGAMOUS and miR172c loci, which are known to be targets of the SEUSS protein. Once the optimization of ChIP technique is completed, ChIPed DNA samples will be sequenced and the resulting reads will be mapped to the Arabidopsis annotated genome to identify SEUSS-bound DNA regions. Our ChIP-Seq data will be compared to transcriptional information to generate models of the gene regulatory networks in the developing ovule.

Funder Acknowledgement(s): NSF-REU 1156419

Faculty Advisor: Miguel Flores,