Scientist Profiles M-R

Sunnybrook Research Institute

Jonathan Rast M.Sc., PhD

Scientist

Sunnybrook Health Sciences Centre
2075 Bayview Ave., Room S1 26b
Toronto, ON
M4N 3M5


Phone: 416-480-5195
Fax: 416-480-5737

Administrative Assistant: Meredith Maloney
Phone: 416-480-6100, ext. 7897
Email: meredith.maloney@sri.utoronto.ca

Education:

  • B.Sc., 1984, Biology, Spring Hill College, USA
  • M.Sc., 1990, Marine Sciences, University of South Florida, USA
  • PhD, 1995, Marine Sciences, University of South Florida, USA

Appointments and Affiliations:

Research Focus:

  • Developmental gene regulatory networks

Research Summary:

We are interested in the genetic programs that regulate mesodermal cell differentiation, particularly those that have homologous counterparts in vertebrate hematopoiesis and innate immunity.

Blood cells and their associated functions have ancient origins in the evolution of metazoans. Thus simple invertebrate animals provide powerful models with which to unravel the complex gene networks that regulate immunity and hematopoiesis in the vertebrates. We use the embryo and larva of the purple sea urchin (Strongylocentrotus purpuratus) for this purpose.

These animals are experimentally amenable to gene network analysis for a variety of reasons including:

  • The simplicity of their morphology
  • The availability of enormous quantities of staged embryos
  • The exceptional efficiency of transgenic analysis
  • The ability to easily and specifically perturb the functions of embryonic genes using antisense technology

The purple sea urchin genome sequence is currently being completed. The addition of this resource establishes the sea urchin as a leading high-throughput model for developmental gene network biology. Importantly, sea urchins are echinoderms, a sister-group of the chordates. They thus have a common genetic heritage with the vertebrates not shared by other important invertebrate models. We are currently analyzing the role of a GATA1/2/3 transcription factor gene in the process and mesodermal cell fate choice and in the development of larval phagocytic cells. This gene provides an anchor point for a gene network level description of the process by which early embryonic specification programs are linked to a later mesodermal cell-type differentiation program.

We are also investigating the functions of other important hematopoietic transcription factor homologs and immune recognition proteins in the development and function of larval immune cells. Our overall approach is to identify important conserved network elements that are essential to hematopoiesis and immunity by comparison to vertebrates, then to expand upon these, taking full advantage of the sea urchin model.

Selected Publications:

See current publications list at PubMed.

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