Localization of Sequences Regulating Drosophila Chorion Gene Amplification and Expression

Abstract

Recently there has been considerable progress in de-termining the structure of numerous eukaryotic genes. Sequences important for the initiation, processing, and termination of gene transcripts have been mapped in detail, and the biochemical characterization f regula-tory factors is progressing rapidly. The elucidation of control mechanisms acting on genes within multicellu-lar organisms during development has proved to be a more difficult problem, however. Experimental sys-tems that unambiguously reproduce developmental controls are rare. During the last 3 years, the develop-ment of gene transfer methods for several higher o-ganisms has facilitated a purely genetic approach to this problem. Modified genes are introduced into the germ line of multicellular organisms uch as Droso-