The goal of Dr. Stephenson's proposed research is to characterize the developmental role of the maternal effect gene swallow. Maternal effect genes are transcribed only during oogenesis: the products are packaged into the egg and are necessary for embryonic development. Dr. Stephenson has cloned the swallow locus, and here proposes a detailed analysis of this gene for the purpose of determining its biochemical and molecular contribution to development. He proposes: 1) Molecular characterization of the swallow gene and its transcript, by sequencing, and S1 nuclease analysis. 2) Analysis of the swallow protein, by generation of antibodies to fusion proteins produced in bacteria and subsequent immunological analysis. These experiments will allow him to characterize physically the swallow protein, and provide a description of its temporal and spatial expression. 3) Determination of the effects of overexpressing swallow protein in the oocyte, or expressing it at inappropriate developmental periods. These experiments will address the question of a temporally-restricted requirement for expression of swallow, and may provide important clues concerning its function. Dr. Stephenson's goals are to understand the nature and developmental effects of maternal contributions to embryogenesis. He is using the powerful genetic and molecular techniques available in Drosophila to approach this problem.
