A cell arrangement specific to thoracic ganglia in the central nervous system of theDrosophila embryo: Its behaviour in homoeotic mutants.

We describe a set of cells in the central nervous system of theDrosophila embryo which are restricted to the thoracic ganglia in the wildtype. Taking these cells as indication of thoracic identity, we find that the ventral cord of embryos homozygous mutant for different bithorax functions and for Polycomb undergoes homoeotic transformations equivalent to those observed in the larval cuticle.