Motoneuron development and spinal cord patterning.
In order for the neuromuscular system to function properly, precise connections must be made between embryonic motoneurons of the brainstem and spinal cord and individual skeletal muscles. Even before connections are made, the btainstem and spinal cord show marked regional differences in gene patterns and in the behavior of motoneuron precursors. Dr. Lance-Jones is interested in the question of how different CNS regions, including their specific motoneuron populations aquire unique identities during early neural development, and how these identities are translated into stereotyped patterns of peripheral connections with muscles. When do motoneurons acquire the ability to recognize their proper target? What are the roles of signals from adjacent non-neural tissue in motoneuron specification. How is the regional expression of transcription factor gene like Hox genes related to the development of specific motoneuron characteristics? How do substances like retinoids and alcohol disrupt the orderly development of these characteristics? Ongoing and proposed studies provide fundamental information about the developmental potential and requirements of motoneuron precursors. Currently, the chick embryo is used as a primary model system and techniques used include embryonic tissue manipulation and gene misexpression via in ovo electroporation.
Shah, V., Drill, E., and Lance-Jones, C. Ectopic expression of Hoxd10 in thoracic spinal segments induces motoneurons with a lumbosacral molecular profile and axon projections to the limb. Developmental Dynamics, 231: 43-56, 2004.