Dr. Kafatos proposes to continue an analysis of cis-regulatory elements of the moth chorion promoters, and to characterize the trans factors by biochemical fractionation, molecular cloning, and functional analysis with in vitro transcription assays. Specific objectives are as follows: 1) Use a reporter lacZ gene to determine in detail elements that are necessary for follicle specific regulation of moth chorion genes transferred into the Drosophila genome. 2) Biochemically fractionate, purify and characterize putative trans-factors from Drosophila and silkmoths. 3) Study the relative affinities of these factors for chorion genes that differ in temporal programming. 4)Molecular cloning of trans-factor sequences. 5) Development of an in vitro transcription system, to assay and confirm the nature of purified or cloned factors. 6) Use of the factor clones to study chorion regulation, e.g. affinities and changes in concentration of the factors during choriogenesis, and their distribution in other tissues and developmental stages. %%% The chorion proteins and used to form the eggshell of the moth and fly. Their synthesis represents an excellent system in which to study the developmentally regulated expression of a complex, multigene family.
