RT Journal Article
T1 The Shark Alar Hypothalamus: Molecular Characterization of Prosomeric Subdivisions and Evolutionary Trends
A1 Santos Durán, Gabriel Nicolás
A1 Ferreiro Galve, Susana
A1 Menuet, Arnaud
A1 Quintana Urzainqui, Idoia
A1 Mazan, Sylvie
A1 Rodríguez-Moldes Rey, María Isabel
A1 Candal Suárez, Eva María
K1 Chondrichthyan
K1 Forebrain
K1 Alar/basal boundary
K1 Evolution
K1 Development
K1 Pax6
K1 Otp
K1 Dlx
AB The hypothalamus is an important physiologic center of the vertebrate brain involved in the elaboration of individual and species survival responses. To better understand the ancestral organization of the alar hypothalamus we revisit previous data on ScOtp, ScDlx2/5, ScTbr1, ScNkx2.1 expression and Pax6 immunoreactivity jointly with new data on ScNeurog2, ScLhx9, ScLhx5, and ScNkx2.8 expression, in addition to immunoreactivity to serotonin (5-HT) and doublecortin (DCX) in the catshark Scyliorhinus canicula, a key species for this purpose since cartilaginous fishes are basal representatives of gnathostomes (jawed vertebrates). Our study revealed a complex genoarchitecture for the chondrichthyan alar hypothalamus. We identified terminal (rostral) and peduncular (caudal) subdivisions in the prosomeric paraventricular and subparaventricular areas (TPa/PPa and TSPa/PSPa, respectively) evidenced by the expression pattern of developmental genes like ScLhx5 (TPa) and immunoreactivity against Pax6 (PSPa) and 5-HT (PPa and PSPa). Dorso-ventral subdivisions were only evidenced in the SPa (SPaD, SPaV; respectively) by means of Pax6 and ScNkx2.8 (respectively). Interestingly, ScNkx2.8 expression overlaps over the alar-basal boundary, as Nkx2.2 does in other vertebrates. Our results reveal evidences for the existence of different groups of tangentially migrated cells expressing ScOtp, Pax6, and ScDlx2. The genoarchitectonic comparative analysis suggests alternative interpretations of the rostral-most alar plate in prosomeric terms and reveals a conserved molecular background for the vertebrate alar hypothalamus likely acquired before/during the agnathan-gnathostome transition, on which Otp, Pax6, Lhx5, and Neurog2 are expressed in the Pa while Dlx and Nkx2.2/Nkx2.8 are expressed in the SPa
PB Frontiers Media
YR 2016
FD 2016-11-24
LK http://hdl.handle.net/10347/16010
UL http://hdl.handle.net/10347/16010
LA eng
NO Santos-Durán GN, Ferreiro-Galve S, Menuet A, Quintana-Urzainqui I, Mazan S, Rodríguez-Moldes I and Candal E (2016) The Shark Alar Hypothalamus: Molecular Characterization of Prosomeric Subdivisions and Evolutionary Trends. Front. Neuroanat. 10:113. doi: 10.3389/fnana.2016.00113
NO This work was supported by grants from the Spanish Dirección General de Investigación-FEDER (BFU2010-15816, BFU2014-58631-P), the Xunta de Galicia (10PXIB200051PR, IN 845B-2010/159, CN 2012/237), the Région Centre, Région Bretagne (EVOVERT grant number 049755; PEPTISAN project), National Research Agency (grant ANR-09-BLAN-026201), CNRS, Universitéd’Orléans and Université Pierre et Marie Curie
DS Minerva
RD 24 abr 2026