Development Genes and Evolution

, Volume 212, Issue 8, pp 399–402

An ascidian engrailed gene

  • Di Jiang
  • William C. Smith
Expression Note

DOI: 10.1007/s00427-002-0255-y

Cite this article as:
Jiang, D. & Smith, W.C. Dev Genes Evol (2002) 212: 399. doi:10.1007/s00427-002-0255-y


The engrailed genes play roles in the maintenance of segment polarity in a variety of animals and in the establishment and maintenance of the mid-brain/hind-brain boundary (MHB) in vertebrates. We isolated an ascidian engrailed gene and analyzed its expression pattern during early development. Expression begins at the neurula stage and is restricted to two cells within the neuroectoderm. At the tail-bud stage engrailed-expressing cells are in the "neck" region of the neural tube, which has been proposed to be the ascidian equivalent of the MHB. These same cells also express PAX2/5/8. We speculate that a structure equivalent to the MHB existed before the split of the three chordate subphyla.

Ascidian Engrailed Mid-brain/hind-brain boundary Segmentation Evolution

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  • Di Jiang
    • 1
  • William C. Smith
    • 1
  1. 1.Department of Molecular, Cellular and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA