RT Journal Article
T1 Regionalization of the shark hindbrain: a survey of an ancestral organization
A1 Rodríguez-Moldes Rey, María Isabel
A1 Carrera de Figueiredo, Iván Manuel
A1 Pose Méndez, Sol María
A1 Quintana Urzainqui, Idoia
A1 Candal Suárez, Eva María
A1 Anadón Álvarez, Ramón
A1 Mazan, Sylvie
A1 Ferreiro Galve, Susana
K1 Rhombomeres
K1 HoxA2
K1 Wnt8
K1 Calretinin
K1 Cartilaginous fishes
K1 Shark embryo
K1 Development
K1 Evolution
AB Cartilaginous fishes (chondrichthyans) represent an ancient radiation of vertebrates currently considered the sister group of the group of gnathostomes with a bony skeleton that gave rise to land vertebrates. This out-group position makes chondrichthyans essential in assessing the ancestral organization of the brain of jawed vertebrates. To gain knowledge about hindbrain evolution we have studied its development in a shark, the lesser spotted dogfish Scyliorhinus canicula by analyzing the expression of some developmental genes and the origin and distribution of specific neuronal populations, which may help to identify hindbrain subdivisions and boundaries and the topology of specific cell groups. We have characterized three developmental periods that will serve as a framework to compare the development of different neuronal systems and may represent a suitable tool for comparing the absolute chronology of development among vertebrates. The expression patterns of Pax6, Wnt8, and HoxA2 genes in early embryos of S. canicula showed close correspondence to what has been described in other vertebrates and helped to identify the anterior rhombomeres. Also in these early embryos, the combination of Pax6 with protein markers of migrating neuroblasts (DCX) and early differentiating neurons (general: HuC/D; neuron type specific: GAD, the GABA synthesizing enzyme) revealed the organization of S. canicula hindbrain in both transverse segmental units corresponding to visible rhombomeres and longitudinal columns. Later in development, when the interrhombomeric boundaries fade away, accurate information about S. canicula hindbrain subdivisions was achieved by comparing the expression patterns of Pax6 and GAD, serotonin (serotoninergic neurons), tyrosine hydroxylase (catecholaminergic neurons), choline acetyltransferase (cholinergic neurons), and calretinin (a calcium-binding protein). The patterns observed revealed many topological correspondences with other vertebrates and led to reconsideration of the current view of the elasmobranch hindbrain segmentation as peculiar among vertebrates.
PB Frontiers Media
YR 2011
FD 2011
LK http://hdl.handle.net/10347/22408
UL http://hdl.handle.net/10347/22408
LA eng
NO Rodríguez-Moldes I, Carrera I, Pose-Méndez S, Quintana-Urzainqui I, Candal E, Anadón R, Mazan S and Ferreiro-Galve S (2011) Regionalization of the shark hindbrain: a survey of an ancestral organization. Front. Neuroanat. 5:16. doi: 10.3389/fnana.2011.00016
NO The present study was supported by grants of Spanish Dirección General de Investigación-FEDER (BFU2007-61154, BFU2010-15816) and of Xunta de Galicia (PGIDIT07PXIB200102PR; 10PXIB200051PR; INCITE09ENA200048ES). Authors also acknowledge the support of the European Community – Research Infrastructure Action under the FP7 “Capacities” Specific Programme (ASSEMBLE grant agreement no. 227799). The EST sequencing project was taken in charge by Génoscope, Evry, France
DS Minerva
RD 24 abr 2026