9509099 Wedeen the investigator will determine whether homologs of genes that control development in an animal like the fruit fly, that generates all of its segments simultaneously, can control development in an animal like the leech, that adds segments progressively. She will examine the expression patterns of genes that are likely to be involved in organizing body pattern in the leech embryo, Helobdella triserialis. The genes to be examined are homologs of the genes engrailed, cubitus interruptus-Dominant, wingless and hedgehog that are expressed in stripco in the embryo of the fruit fly, Drosophila melanogaster, and have been shown in that insect to be required for normal development of embryonic segments. The cells in the leech embryo expressing these genes will be identified by their cell lineage and will be ablated by laser to examine what role these cells play in embryonic development.
