Determination of Anteroposterior Polarity in <i>Drosophila</i>

TLDR

Pattern formation in Drosophila embryos is governed by anterior and posterior pole activities that induce and polarize segmentation, while terminal regions develop independently via a third class of genes. A small set of maternal genes essential for the anterior and posterior activities has been identified; mutants lacking these genes fail to develop either the anterior or posterior segments.

Abstract

The principles of pattern formation in embryogenesis can be studied in Drosophila by means of a powerful combination of genetic and transplantation experiments. The segmented pattern of the Drosophila embryo is organized by two activities localized at the anterior and posterior egg poles. Both activities exert inducing and polarizing effects on the pattern when transplanted to other egg regions. A small set of maternal genes have been identified that are required for these activities. Mutants in these genes lack either the anterior or posterior part of the segmented pattern. The unsegmented terminal embryonic regions require a third class of genes and form independently of the anterior and posterior centers.