title: The homeobox leucine zipper gene Homez plays a role in Xenopus laevis neurogenesis.
abstract: The Homez gene encodes a protein with three atypical homeodomains and two leucine zipper motifs of unknown function. Here we show that during neurula stages, Xenopus Homez is broadly expressed throughout the neural plate, the strongest expression being detected in the domains where primary neurons arise. At later stages, Homez is maintained throughout the central nervous system in differentiating progenitors. In accordance with this expression, Homez is positively regulated by neural inducers and by Ngnr1 and negatively by Notch signaling. Interference with Homez function in embryos by injection of an antisense morpholino oligonucleotide results in the specific disruption of the expression of late neuronal markers, without affecting the expression of earlier neuronal and early neurectodermal markers. Consistent with this finding, Homez inhibition also interferes with the expression of late neuronal markers in Ngnr1 overexpressing animal cap explants and in Notch inhibited embryos. In gain of function experiments, Homez inhibits the expression of late neuronal markers but has no effect on earlier ones. These data suggest a role for Homez in neuronal development downstream of proneural/neurogenic genes.
authors: Laboratoire de Génétique du Développement, Université Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires, Rue des Profs. Jeener et Brachet 12, B-6041 Gosselies, Belgium.
authors: Rym
authors: R
authors: Ghimouz
authors: Isabelle
authors: I
authors: Bar
authors: Julie
authors: J
authors: Hanotel
authors: Beatica
authors: B
authors: Minela
authors: Marc
authors: M
authors: Keruzore
authors: Aurore
authors: A
authors: Thelie
authors: Eric J
authors: EJ
authors: Bellefroid
mesh_terms: D000818:Animals; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D016350:Leucine Zippers; D054258:Neural Plate / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D029867:Xenopus Proteins / Q000235:genetics / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics
chemical_list: C569217:HOMEZ protein, Xenopus; D018398:Homeodomain Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins