Developmental analysis of some mutants of the bithorax system of Drosophila

Abstract

Mutants in the bithorax system of Drosophila produce homeotic transformations that affect the mesothoracic, metathoracic and first abdominal segments. In the present report we describe a clonal analysis of the development of those mutants transforming the metathorax and first abdominal segments into mesothorax. The main results indicate that (1) The normal dorsal metathoracic (haltere) disk has similar developmental parameters to the dorsal mesothoracic disk. The main difference is that the initial and final numbers of cells are different in both disks. (2) In flies mutant for Bithorax and postbithorax (which transform the haltere into wing) the transformed haltere disk has the same initial and final number of cells as the normal wing disk. (3) In morphogenetic mosaics homozygous bithorax (and postbithorax) clones express their genotype autonomously regardless of the genotype of surrounding haltere cells. This autonomy is expressed in a regulation of the number of adult cells per compartment, typical cell affinities and final cuticular differentiation. © 1976 Springer-Verlag.