ABSTRACT
About 184 P[lac,ry+]A insertions (O’Kane & Gehring, 1987) have been incorporated into the genome via P element-mediated transformation. The temporal-spatial localization of β-galactosidase, synthesized by these insertions during oogenesis, is described. 32 % present control levels of endogenous β-galactosidase expression and 68 % show novel patterns. 13 % of the insertions are germline-specific; 33%, follicle-cell-specific; 20 % are expressed in both germ line and follicle cells; and 2%, specific to the germarium. Several lines exhibit strict temporal-spatial localiz ations of β-galactosidase; notably those expressed in specific populations of follicle cells. The results are discussed with respect to some of the positional information encoded in the genome to which the insertions respond, the use of the insertions as markers for cell differentiation and the potential of the technique for isolating new genes involved in egg production.
