Development Genes and Evolution

, Volume 211, Issue 2, pp 96–102

Homeotic evidence for the appendicular origin of the labrum in Tribolium castaneum

  • M. Susan Haas
  • Susan J. Brown
  • Richard W. Beeman
Short Communication

DOI: 10.1007/s004270000128

Cite this article as:
Haas, M., Brown, S. & Beeman, R. Dev Genes Evol (2001) 211: 96. doi:10.1007/s004270000128

Abstract.

The ontogeny of the insect labrum, or upper lip, has been debated for nearly a century. Recent molecular data suggest a segmental appendage origin of this structure. Here we report the first arthropod mutation associated with a homeotic transformation of the labrum. Antennagalea-5 (Ag5) transforms both antennal and labral structures to resemble those of gnathal appendages in Tribolium castaneum. This labral transformation suggests that the labrum is a fused structure composed of two pairs of appendage endites, and is serially homologous to the gnathal appendages.

Insect head Homeotic transformation Mandible Labrum Appendage

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • M. Susan Haas
    • 1
  • Susan J. Brown
    • 2
  • Richard W. Beeman
    • 1
  1. 1.USDA, ARS, Grain Marketing and Production Research Center, Manhattan, KS 66502, USA
  2. 2.Division of Biology, Ackert Hall, Kansas State University, Manhattan, KS 66506, USA