9511042 Eagleson This research will investigate early forebrain development in the vertebrate. The animal to be used was chosen because a mutation found within this species directly affects forebrain and eye development, and this mutation provides a negative condition whereby development is disrupted. Using normal and mutant organisms, a detailed forebrain fate map will be produced with fluorescent labeling techniques. A comparison of the mutant and normal embryo neural plate brain fates will test whether, and when, specific midline early neural plate tissue is defective in the mutant embryos. Using in situ hybridization techniques, stage by stage gene expression changes in forebrain specific genes will be followed in normal and mutant embryos. These studies will test to see if differences in the timing or amount of forebrain specific gene expression occurs in mutant and normal embryos, and if gene expression events can be related to the specific forebrain defects. Additional studies will test how the mutant condition might alter later axon growth and neural connections. These studies will follow axon and synapse development in normal and mutant embryos by using immunocytochemistry for a protein that is formed in developing neurons. These studies will reveal how a single mutant gene can result in defects that manifest themselves much later in development. In addition these studies will provide a developmental framework and model for further studies investigating vertebrate neural development.
