The William Thompson Lab
This laboratory is a joint venture between Dr. Bill Thompson(Plant Biology) and Dr. George Allen (Horticulture Science). Our overall goal is to understand basic factors that influence gene expression and use that understanding to enhance gene transfer technology for crop improvement.  Most of our current projects are concerned with nuclear structure, DNA replication, plant transformation, and expression of transferred genes.

NSF Grant to Fund Study of Origins of Plant DNA Replication


Maize Transformation Project Abstract:
Although genetic transformation systems for maize are well established in private laBOratories, the lack of such systems is still a key limitation for public researchers. this is because most public research groups do not have access to the resources and infrasturcture ncessary for Maize samplemaize transformation by currently available procedures. In addition, the current technology has serious limitations, including low efficiency and throughput, difficulty in inbred line transformation, unpredicatable transgene copy numbers and integrity, and undesirable transgene silencing during development and over generations.

We are conducting research aimed at establishing a robust maize transformation technology by:

  • Developing a routine Agrobacterium-mediated transformation system.
  • Enhancing transgeneinegration and expression
  • Investigating germline transformation protocols
  • Exploring inbred line transformation.

In addition, we will facilitate transfer of improved protocols to the public sector by providing a more efficient transformation service and organizing transformation workshops during the course of this program.

At NCSU, we are concerned largely with meristem transformation, one of the two approaches outlined in the proposal for avoiding the dedifferentiation and regeneration steps normally emplyed in plant transformation. Such "germline transformation" protocols should reduce the somaclonal variation that plagues present procedures, and may eventually facilitate transformation of elite inbred lines rather than genetically heterogeneous hybrid germplasm.

Other work at NCSU is focused on enhancing transgene integration and expression, using our matrix attachment region technology and other approached to reduce gene silencing.

Participants:

This is a multi-institutional project funded by the NSF Plant Genome Research Program. It is lead by Kan Wang (Iowa State University. Co-PI's are Stanton Gelvin (Purdue University), Heidi Kaeppler (Univ. of Wisconsin), and Bill Thompson (NCSU)

NCSU participants include Tuyen Nguyen, Anton Callaway, George Allen, Yuko Nishimura, and Alan Chen, and Rosie Whitney.

DNA Replication Project Abstract:

Although is is well known that eukaryotes initiate DNA replication at multiple positions in their genomes, there is little information aBOut the replication origins in plant chromosomes or their relationship to other chromosomal functional domains. The goal of this research is to construct and overlay chromosomalmaps of replication origins, matrix attachment regions, modified histones, DNA methylation levels and transcription. Thse experiments will combine powerful genomic technologies with molecular, cellular and immunological tools to generate functional maps for the short arm of rice chromosome 1 and all of Arabidopsis chromosome 4. Comparison of these maps with each other and with data for other eukaryotes will provide insight into chromosomal features conserved among al eukaryotes and identify characteristics unique to the plant kingdom.

These studies will also provide a foundation for developing new transformation and gene targeting methods, plant artificial chromosome vectors, and related technologies that will help support a new generation of genetic engineering technologies. The project will generate new genomic information and tools that will be accessible to other members of the plant science community via the web. the genomic arrays for rice and Arabidopsis designed as part of this group will be available to the community. The project will provide training at the undergraduate, graduate and postdoctoral levels in state-of-the-art functional genomic and bioinformatics techniques. We will conduct workshops on genomic analysis tools that will be accessible to scientists in the southeastern US and to faculty and students at historically black and minority institutions. We will also work with local educators to develop teaching tools useful for presenting genomics concepts to high school students.

Participants
This is a multi-institutional project funded by the NSF Plant Genome Research Program.
NCSU : Bill Thompson, Linda Hanley-Bowdoin,
Co-PI's: George Allen, Bryon Sosinski , Doreen Main (Clemson University) , Rob Martienssen (Cold Spring Harbor)

In the group at NCSU, other participants currently include Miguel Flores,Tae-Jin Lee, Randy Shultz, and Sharon Settlage. We are especially proud of the fact that the idea for this proposal originated in class proposal prepared by Randy Shultz, which eventually brought Linda and Bill together to initiate the project.

NSF Grant to Fund Study of Origins of Plant DNA Replication

Matrix attachment Regions

This is a long-term, ongoing project involving three collaborating laBOratories at NCSU and funded from a variety of sources including federal grants and industrial contributions. Matrix Attachment Regions (MARs) are DNA sequences capable of specific binding to nuclear proteins that are part of a fibrillar nuclear matrix analogous to the cytoskeleton. Most of our current work is an attempt to understand and extend our original observation that MARs in transgene constructs can greatly stimulate transgene expression under certain conditions in which gene silencing would otherwise prevent expression. As an extension of this work, we are also interested in gene silencing mechanisms and in other DNA elements, such as insulators, that interact with proteins to alter chromatin structure and/or gene expression. An overview of our earlier work is presented by Allen et al., Plant Molecular Biology 43: 361-376 (2000). We are currently assessing the relative importance of MAR effects on transcriptional and post-transcriptional gene silencing, as well as the ability of MARs to reduce the gene silencing that sometimes occurs in advanced generations of transgenic breeding programs. We are also collaborating to apply this technology in several breeding efforts.

Participants:

This project is a collaboration involving two additional laboratories at NCSU Dr. Arthur Weissinger in Crop Science and Dr. Steve Spiker in Genetics