title: Hau-Pax6A expression in the central nervous system of the leech embryo.
abstract: The leech Helobdella sp. (Austin) has two genes of the Pax6 subfamily, one of which is characterized in detail. Hau-Pax6A was expressed during embryonic development in a pattern similar to other bilaterian animals. RNA was detected in cellular precursors of the central nervous system (CNS) and in peripheral cells including a population associated with the developing eye. The CNS of the mature leech is a ventral nerve cord composed of segmental ganglia, and embryonic Hau-Pax6A expression was primarily localized to the N teloblast lineage that generates the majority of ganglionic neurons. Expression began when the ganglion primordia were four cells in length and was initially restricted to a single cell, n(s).a, whose descendants will form the ganglion's anterior edge. At later stages, the Hau-Pax6A expression pattern expanded to include additional CNS precursors, including some descendants of the O teloblast. Expression persisted through the early stages of ganglion morphogenesis but disappeared from the segmented body trunk at the time of neuronal differentiation. The timing and iterated pattern of Hau-Pax6A expression in the leech embryo suggests that this gene may play a role in the segmental patterning of CNS morphogenesis.
authors.affiliation: Section of Molecular Cell and Developmental Biology, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Ian K
authors.initials: IK
authors.lastname: Quigley
authors.forename: Xuanhua
authors.initials: X
authors.lastname: Xie
authors.forename: Marty
authors.initials: M
authors.lastname: Shankland
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019070:Cell Lineage; D002490:Central Nervous System / Q000196:embryology* / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D007865:Leeches / Q000196:embryology* / Q000235:genetics*; D008969:Molecular Sequence Data; D051761:Paired Box Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D013997:Time Factors
chemical_list: D051761:Paired Box Transcription Factors