title: Pax-Six-Eya-Dach network during amphioxus development: conservation in vitro but context specificity in vivo.
abstract: The Drosophila retinal determination gene network occurs in animals generally as a Pax-Six-Eyes absent-Dachshund network (PSEDN). For amphioxus, we describe the complete network of nine PSEDN genes, four of which-AmphiSix1/2, AmphiSix4/5, AmphSix3/6, and AmphiEya-are characterized here for the first time. For amphioxus, in vitro interactions among the genes and proteins of the network resemble those of other animals, except for the absence of Dach-Eya binding. Amphioxus PSEDN genes are expressed in highly stage- and tissue-specific patterns (sometimes conspicuously correlated with the local intensity of cell proliferation) in the gastrular organizer, notochord, somites, anterior central nervous system, peripheral nervous system, pharyngeal endoderm, and the likely homolog of the vertebrate adenohypophysis. In this last tissue, the anterior region expresses all three amphioxus Six genes and is a zone of active cell proliferation, while the posterior region expresses only AmphiPax6 and is non-proliferative. In summary, the topologies of animal PSEDNs, although considerably more variable than originally proposed, are conserved enough to be recognizable among species and among developing tissues; this conservation may reflect indispensable involvement of PSEDNs during the critically important early phases of embryology (e.g. in the control of mitosis, apoptosis, and cell/tissue motility).
authors.affiliation: Institute of Molecular Genetics, Videnska 1083, 14220 Prague 4, Czech Republic.
authors.forename: Zbynek
authors.initials: Z
authors.lastname: Kozmik
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Holland
authors.forename: Jana
authors.initials: J
authors.lastname: Kreslova
authors.forename: Diana
authors.initials: D
authors.lastname: Oliveri
authors.forename: Michael
authors.initials: M
authors.lastname: Schubert
authors.forename: Kristyna
authors.initials: K
authors.lastname: Jonasova
authors.forename: Linda Z
authors.initials: LZ
authors.lastname: Holland
authors.forename: Mario
authors.initials: M
authors.lastname: Pestarino
authors.forename: Vladimir
authors.initials: V
authors.lastname: Benes
authors.forename: Simona
authors.initials: S
authors.lastname: Candiani
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D002490:Central Nervous System / Q000254:growth & development / Q000378:metabolism; D043344:Chordata / Q000235:genetics / Q000254:growth & development*; D000078404:Epidermal Cells; D004817:Epidermis / Q000254:growth & development; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000254:growth & development / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D009475:Neurons, Afferent / Q000378:metabolism; D010802:Phylogeny; D010903:Pituitary Gland, Anterior / Q000254:growth & development / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger