The development of the metameric body plan of the insect Drosophila melanogaster has emerged as the principal model system for studying the genetic and molecular basis of embryonic pattern formation. The objectives of this proposal are to make a comprehensive study of the interactions between early-acting genes of the zygote that control subsequent gene expression and determine the fates of groups of cells. By using molecular probes (cloned DNA and antibodies) to study gene expression in wild-type and a great variety of mutant embryos, the genetic system that controls the time, place and level of pattern- regulating gene expression will be systematically dissected. Individual regulatory phenomena revealed by these previous studies may eventually be studied at the biochemical level in order to determine the mechanisms of gene regulation and function. The conceptual framework of development being revealed by studies in Drosophila relates to the fundamental aspects of any complex organism. The control of cell proliferation, gastrulation, germ layer differentiation, position-specific gene expression, and the number and differentiation of body parts and appendages are central themes to all complex animals. By exploiting the genetic approach available in Drosophila and combining it with advanced molecular and embryological techniques, it is likely that more will be known about the growth, development, and differentiation of the fruit fly than any other animal species. %%% The development of a complex animal from a simple fertilized egg is one of the most important problems in biology that remains to be solved. In Dr. Carroll's laboratory, he is studying the genes that control this process in the fruit fly, one of the best understood genetic model system for developmental studies. By studying these genes, and the protein molecules that they encode, he aims to understand how cells are organized into distinct groups to form the different tissues, organs, and regions of the animal's body.
