The cell lineage of segments and parasegments in Drosophila

Abstract

In Drosophila , m any good methods of single cell marking are available using mutations that alter the structure of the cuticle or those that alter the activity of an enzyme. In situ hybridization of nucleic acids to tissue sections now allows the observer to follow movements of groups of cells in the embryo. These methods challenge the traditional picture of metamerization in the insect embryo: it seems that both in the ectoderm and the mesoderm the embryo is first divided not into segments but into compartments and parasegments. In the ectoderm a parasegment comprises a posterior compartment of one segment and the anterior compartment of the next. In the mesoderm the parasegments are probably not subdivided into compartments.