Fjx1, the murine homologue of the Drosophila four-jointed gene, codes for a putative secreted protein expressed in restricted domains of the developing and adult brain

Mech Dev. 1999 Feb;80(2):213-7. doi: 10.1016/s0925-4773(98)00218-4.


The Drosophila gene four jointed (fj) codes for a secreted or cell surface protein important for growth and differentiation of legs and wings and for proper development of the eyes. Here we report the cloning of the mouse four-jointed gene (fjx1) and its pattern of expression in the brain during embryogenesis and in the adult. In the neural plate, fjx1 is expressed in the presumptive forebrain and midbrain, and in rhombomere 4, however a small rostral/medial area of the forebrain primordium is devoid of expression. Expression of fjx1 in the neural tube can be divided into three phases. (1) In the embryonic brain fjx1 is expressed in two patches of neuroepithelium: in the midbrain tectum and the telencephalic vesicles. (2) In fetal and early postnatal brain fjx1 is expressed mainly by the primordia of layered telencephalic structures: cortex (ventricular layer and cortical plate), olfactory bulb (subependymal layer and in the mitral cell layer). In addition expression is observed in the superior colliculus. (3) In the adult, fjx1 is expressed by neurones evenly distributed in the telencephalon (isocortex, striatum, hippocampus, olfactory bulb, piriform cortex), in the Purkinje cell layer of the cerebellum, and numerous medullary nuclei. In the embryo, strong expression can further be seen in the apical ectodermal ridge of fore- and hindlimbs and in the ectoderm of the branchial arches.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain / embryology
  • Brain / growth & development
  • Brain / metabolism*
  • DNA, Complementary / genetics
  • Drosophila Proteins*
  • Embryonic and Fetal Development / genetics
  • Fetal Proteins / biosynthesis
  • Fetal Proteins / genetics
  • Fetal Proteins / metabolism
  • Gene Expression Regulation, Developmental*
  • Intercellular Signaling Peptides and Proteins
  • Membrane Glycoproteins / biosynthesis
  • Membrane Glycoproteins / genetics*
  • Membrane Glycoproteins / metabolism
  • Mice / embryology
  • Mice / genetics*
  • Mice / growth & development
  • Molecular Sequence Data
  • Morphogenesis / genetics
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Organ Specificity
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • DNA, Complementary
  • Drosophila Proteins
  • Fetal Proteins
  • Fjx1 protein, mouse
  • Intercellular Signaling Peptides and Proteins
  • Membrane Glycoproteins
  • Nerve Tissue Proteins
  • fj protein, Drosophila

Associated data

  • GENBANK/AJ009634