aubergine enhances oskar translation in the Drosophila ovary

Although translational regulation of maternal mRNA is important for proper development of the Drosophila embryo, few genes involved in this process have been identified. In this report, we describe the role of aubergine in oskar translation. Previously, aubergine has been implicated in dorsoventral patterning, as eggs from aubergine mutant mothers are ventralized and seldom fertilized (Schupbach, T. and Wieschaus, E. (1991) Genetics 129, 1119-1136). We have isolated two new alleles of aubergine in a novel genetic screen and have shown that aubergine is also required for posterior body patterning, as the small fraction of eggs from aubergine- mothers that are fertilized develop into embryos which lack abdominal segmentation. Although aubergine mutations do not appear to affect the stability of either oskar mRNA or protein, the level of oskar protein is significantly reduced in aubergine mutants. Thus, aubergine is required to enhance oskar translation. While aubergine-dependence is conferred upon oskar mRNA by sequences in the oskar 3' UTR, aubergine may influence oskar translation through an interaction with sequences upstream of the oskar 3' UTR.