TEMPORAL PATTERNS OF GENE-EXPRESSION IN THE ANTENNA OF THE ADULT DROSOPHILA-MELANOGASTER

The time course of gene expression in the adult fruit fly has been par tially characterized by using enhancer trap and reporter gene construc ts that mark 49 different genes. The relative intensity of the reporte r protein in individual cells of the antennae was measured as a functi on of adult age. Most genes showed a graduated expression, and the int ensity of expression had a reproducible and characteristic time course . Different genes displayed different temporal patterns of expression and more often than not the pattern of expression was complex. We foun d a number of genes having patterns that scaled with life span. In the se cases the intensity of gene expression was found to be invariant wi th respect to biological time, when expressed as a fraction of the lif e span of the line. The scaling was observed even when life span was v aried as much as threefold. Such scaling serves to (1) further demonst rate that deterministic mechanisms such as gene regulation act to gene rate the temporal patterns of expression seen during adult life, (2) i ndicate that control of these regulatory mechanisms is linked to life span, and (3) suggest mechanisms by which this control is accomplished . We have concluded that gene expression in the adult fly is often reg ulated in a fashion that allows for graduated expression over time, an d that the regulation itself is changing throughout adult life accordi ng to some prescribed program or algorithm.