- Embryonic development and organogenesis involve integration of numerous genetic and signaling pathways. Developmental complexity needs to be understood to assess the major mechanisms of embryogenesis. Tissues from multiple sources must interact with one another to signal, and induce each other, in complex and interrelated steps. Because the interactions are so complex, developmental defects can occur. In order to understand congenital birth defects, and provide part of the basic scientific framework for translational therapies, we use chick, mouse and zebrafish vertebrate animal models to understand normal and abnormal development. We are particularly interested in mechanisms of tissue specification, morphogenesis and patterning of regional identity during vertebrate development.
- The middle ear relays and amplifies sound from the environment to the inner ear, with developmental defects in this compound structure resulting in conductive hearing loss. Conductive hearing loss accounts for approximately ten percent of congenital hearing loss, which is one of the most common birth defects. However, we need more information about how these middle ear defects arise, so as to understand the molecular mechanism of the different aspects of middle ear patterning. Our research hopes to gain insight into the mechanism of morphogenesis of the middle ear skeletal elements.
A fascinating question related to vertebrate organogenesis is how a group of multipotent progenitor cells are able to self-assemble to form an organ specific pattern. The answer lies in the understanding of two sequential events: firstly, the specification of progenitor cells to a particular fate and secondly, the physical mechanism of the self-assembly of those cells. These events lay out the characteristic template of an organ primordia in the embryo. We aim to understand these two events from the perspective of middle ear morphogenesis.
- We are also interested in neural tube defects and in particular caudal spine birth defects involving dysgenesis or degeneration of the lower vertebrae and associated structures. The Araucana chicken breed have ear tufts, lay blue eggs and are rumpless, lacking tails. Our aim is to identify the gene responsible for this autosomal dominant Araucana phenotype. This gene mutation leads to mesodermal defects that potentially influence several developmental processes, inculding somitogenesis, axial elongation and secondary neurulation. Genetic and morphological characterization of the downstream effects of this Araucana mutation will inform and refine the current model of posterior embryo development.