Notch expression in the developing chick optic tectum

RAPACIOLI, MELINA; RODRIGUE CELIN, ALEJANDRA; DUARTE, SANTIAGO; ORTALLI, ANA LAURA; TERUEL, LUISA R; SANCHEZ, VIVIANA; SCICOLONE, GABRIEL; FLORES, VLADIMIR

San Francisco

Congreso; Society for Developmental Biology 68th Annual Meeting.; 2009

Society for Developmental Biology

Society for Developmental Biology 68th Annual MeetingSan Francisco, USA 23-27 July, 2009Notch expression in the developing chick optic tectumRapacioli M, Rodríguez Celín A, Duarte S, Ortalli A, Teruel L, Sánchez V, Scicolone G, Flores VThe present work analyzes the developmental pattern of Notch1 immunolabeling in the developingoptic tectum (OT) from E2 (neuroepithelium) until E12 (end of basic laminar organization). Duringthe early developmental stages (DS) Notch expression is restricted to progenitor neuroepithelialcells (PNEs) bodies (generative zone). This zone is surrounded by Notch negative, NeuroD-, βIIItubulin-and Syt1-positive postmitotic premigratory neurons. This pattern persists during theneuronogenic phase revealing a role of Notch signaling in maintaining PNE cell population byinhibiting neuronal differentiation. Hes5 is not co-expressed by PNEs suggesting that it does notparticipate in Notch signaling during these DSs. When the first transitory cell compartment (TCC1)appears, these differentiating neurons express cytoplasmic Notch staining revealing a secondphase of Notch activity associated to neuronal differentiation. From this DS onwards neurons coexpressNotch and Hes5. As development progresses, nuclear Notch staining is observed in theseneurons indicating an increasing nuclear translocation. Simultaneously, the neuropile superficial toTCC2 displays intense neurite staining suggesting a role of Notch signaling in neuritogenesis. Later,scattered differentiating neurons within TCC3 and 4 start to display nuclear Notch staining. By E12,Notch is also expressed by radial and migrating glial revealing a role of Notch signaling duringgliogenesis. These findings suggest multiple developmental roles for the Notch signaling pathway.Supported by grants from CONICET (Argentina)