Our laboratory is interested in the genetic control of early mammalian development,
from the first cleavage of the fertilized zygote through implantation, gastrulation,
and early organogenesis. We use a variety of approaches to study the determination of
cell lineages and the interactions of the developing embryo with the maternal environment,
taking advantage of both naturally occurring and experimentally induced mutations.
The major strength of the laboratory is the combination of classic experimental embryology
techniques with molecular biology and targeted mutagenesis.

The major project in the laboratory is the study of a recently discovered family of
transcription factor genes, the T-box gene family. These genes share a conserved DNA-binding
motif first found in the Brachyury locus. The genes are highly conserved in evolution and
have been implicated in the control of mesoderm formation and in inductive interactions in
the organogenesis of organs such as mammary gland, heart, lung, and limbs. Several mutations
in human T-box genes have been shown to be responsible for developmental birth defects and
by using targeted mutagenesis, we have produced mouse models for the human DiGeorge syndrome
(Tbx1) and the ulnar mammary syndrome (Tbx3). In addition, we are investigating the role of
Tbx6 in somite specification and the decision between neural and mesodermal fates, and the
roles ofTbx2, Tbx3, and Tbx4 in heart, limb and eye development. Our interest
is in understanding how these genes control cell fate and tissue specification decisions during
early development.