Smith, J.L., Wilson, J.E. and Macdonald, P.M. (1992).
Overexpression of oskar directs ectopic activation of nanos and presumptive pole cell formation in Drosophila embryos.
Cell 70, 849-859.
Abstract
In Drosophila, a small group of maternal effect genes, including oskar, defines a shared pathway leading to the provision of two determinants at the posterior pole of the embryo. One determinant is the posterior body patterning morphogen nanos, and the other directs germ cell formation. Overexpression of oskar causes the pathway to be hyperactivated. Excess nanos activity is present throughout the embryo and more posterior pole cells form. In addition, presumptive pole cells appear at a novel anterior position. Strikingly, formation of these ectopic pole cells is enhanced in nanos mutants. This observation may reflect competition between nanos and the germ cell determinant for a shared and limiting precursor.