Santos Durán, Gabriel NicolásFerreiro Galve, SusanaMenuet, ArnaudMazan, SylvieRodríguez-Moldes Rey, María IsabelCandal Suárez, Eva María2020-05-182020-05-182018Santos-Durán, G. N., Ferreiro-Galve, S., Menuet, A., Mazan, S., Rodríguez-Moldes, I., & Candal, E. (2018). The Shark Basal Hypothalamus: Molecular Prosomeric Subdivisions and Evolutionary Trends. Frontiers in neuroanatomy, 12, 17.http://hdl.handle.net/10347/22374The hypothalamus is a key integrative center of the vertebrate brain. To better understand its ancestral morphological organization and evolution, we previously analyzed the segmental organization of alar subdivisions in the catshark Scyliorhinus canicula, a cartilaginous fish and thus a basal representative of gnathostomes (jawed vertebrates). With the same aim, we deepen here in the segmental organization of the catshark basal hypothalamus by revisiting previous data on ScOtp, ScDlx2/5, ScNkx2.1, ScShh expression and Shh immunoreactivity jointly with new data on ScLhx5, ScEmx2, ScLmx1b, ScPitx2, ScPitx3a, ScFoxa1, ScFoxa2 and ScNeurog2 expression and proliferating cell nuclear antigen (PCNA) immunoreactivity. Our study reveals a complex genoarchitecture for chondrichthyan basal hypothalamus on which a total of 21 microdomains were identified. Six belong to the basal acroterminal region, the rostral-most point of the basal neural tube; seven are described in the tuberal region (Tu/RTu); four in the perimamillar region (PM/PRM) and four in the mamillar one (MM/RM). Interestingly, the same set of genes does not necessarily describe the same microdomains in mice, which in part contributes to explain how forebrain diversity is achieved. This study stresses the importance of analyzing data from basal vertebrates to better understand forebrain diversity and hypothalamic evolution.engCopyright © 2018 Santos-Durán, Ferreiro-Galve, Menuet, Mazan, Rodríguez-Moldes and Candal. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these termshttps://creativecommons.org/licenses/by/4.0/ChondrichthyanBasal hypothalamusEvo-devoProsomeric modelSegmentsShhPCNAjournal article10.3389/fnana.2018.000171662-5129open access