Effects of deficiencies in the engrailed region of Drosophila melanogaster

Dev Biol. 1983 Nov;100(1):227-37. doi: 10.1016/0012-1606(83)90215-4.

Abstract

The engrailed gene of Drosophila melanogaster is believed to be involved in control of determination and differentiation of posterior compartments. en1/en1 causes a partial transformation of the posterior compartment of wing and first leg to mirror-image anterior, which prompted the hypothesis that engrailed + is a "selector gene" required for the posterior pathway decision. The incomplete transformation was thought due to residual en+ activity in en1; a deletion of engrailed (en28) was constructed to determine if a complete transformation can occur. en28 is homozygous lethal and cell lethal. en28/en1 survives to adult stage, but causes a weaker transformation than en1/en1, indicating that en1 is not a simple hypomorph. A more distal deletion, en30, survives over en-lethal alleles. Both en30/en1 and en28/en30 survive to adult stage, but do not cause a stronger posterior to anterior transformation than en1/en1; thus this effect may be allele specific. New abnormalities included (1) transformation of the posterior wing blade to haltere, an effect dependent on the bx+ (but not pbx+) pseudoallele of the bithorax complex; (2) abnormal bristle pattern, tarsal fusion, and degenerate posterior claws of all legs. Although these abnormalities are posterior compartment specific, they are not expected of a "selector gene." Thus the function of engrailed may be more complex than originally believed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / genetics*
  • Extremities / embryology
  • Limb Deformities, Congenital
  • Mutation
  • Phenotype
  • Wings, Animal / abnormalities
  • Wings, Animal / embryology