Dr. Holland proposes to work at the interface between the fields of evolution and development with the overall purpose of understanding the origin of the vertebrates from the invertebrates. The most tractable goal is to establish homologies between expression domains of pattern controlling genes (e.g. homeobox genes) during ontogeny of lancelets (amphioxus) and tunicates. These genes will be isolated and sequenced and will be used to prepare riboprobes and antibodies for detection of the gene products within the context of the embryonic and larval tissues. By comparing the protochordate expression domains to those already known for developing vertebrates, Dr. Holland the can generate unprecedented new homologies and use them to evaluate existing theories of vertebrate origins and possibly as a basis for new hypotheses. The initial study has already yielded new insights into the evolutionary origin of the vertebrate head and brain.
