Hroth an orthodenticle-related homeobox gene of the ascidian, Halocynthia roretzi: its expression and putative roles in the axis formation during embryogenesis

Mech Dev. 1996 Nov;60(1):59-71. doi: 10.1016/s0925-4773(96)00600-4.


To obtain insight into the axis-forming mechanism in ascidian embryogenesis, Hroth, an ascidian counterpart of orthodenticle/otx, was isolated from Halocynthia roretzi and its expression in embryogenesis was examined by whole mount in situ hybridization. It was revealed that Hroth is expressed in both involuting mesoendoderm and anterior ectoderm during gastrulation while later expression is restricted to the sensory vesicle and anterior epidermis. Expression pattern of Hroth around gastrulation was compared with that of Hrlim, the ascidian LIM class homeobox gene that is known to be expressed during gastrulation. In the light of the present findings on the expression of Hroth, properties of the axis-forming mechanism in ascidian embryogenesis are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Body Patterning / genetics*
  • Cloning, Molecular
  • Drosophila Proteins
  • Ectoderm / metabolism
  • Endoderm / metabolism
  • Epidermis / metabolism
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / metabolism*
  • In Situ Hybridization
  • Mesoderm / metabolism
  • Molecular Sequence Data
  • Nervous System / embryology
  • Nervous System / metabolism
  • Time Factors
  • Tissue Distribution
  • Urochordata / embryology*


  • Drosophila Proteins
  • Homeodomain Proteins
  • Hrlim protein, Halocynthia roretzi
  • Hroth protein, Halocynthia roretzi
  • oc protein, Drosophila

Associated data

  • GENBANK/D84062