Regulation of development in the nematode Caenorhabditis elegans
Our
broad goal is to understand the regulation of animal development at the
molecular level. We are particularly interested in controls of cell
fate and patterning within multicellular tissues. Our experimental
approach relies on the powerful genetics, simple anatomy and complete
genome sequence of the nematode C. elegans. This model organism
provides a way to identify and analyze regulators that are used
throughout the animal kingdom for basic processes of development. Our
work concerns three primary areas:
Signal transduction and regulation of proliferation
Cells
signal back and forth to each other during development to control
growth, differentiation and pattern. We have identified the core
components of a signal transduction pathway that regulates induction of
the germ line tissue: (1) the GLP-1 membrane receptor, (2) the LAG-1
DNA binding protein, (3) the LAG-2 signaling ligand, and (4) the LAG-3
co-activator. We are exploring how this signaling pathway controls
growth and differentiation of the germline tissue.
Translational control and controls of cell fate
Messenger
RNAs are commonly controlled during germline development and early
embryogenesis at the translational level. In collaboration with Dr.
Marvin Wickens, we used the yeast three-hybrid system to identify a
trans-acting regulator that acts through the 3' untranslated region of
fem-3 mRNA to control the decision between spermatogenesis and
oogenesis. The regulator is called FBF, for fem-3 binding factor. FBF
is encoded by two genes, fbf-1 and fbf-2, and is homologous to the
Drosophila translational regulator known as Pumilio. We are currently
asking how FBF and other Pumilio-related proteins in C. elegans
regulate germline development.
Organogenesis
Organs
are generated from groups of cells that work together to complete the
complex functions of the organ. We have conducted mutagenesis screens
to identify genes that control assembly of the four-celled gonadal
primordium and development of that primordium to generate either a
hermaphrodite symmetrical or a male asymmetrical gonad. Our goals are
to learn how organ polarity is established and how epithelial tissues
are regulated to generate individual substructures within an organ.
