Spatial-temporal expressions of Crumbs and Nagie oko and their interdependence in zebrafish central nervous system during early development.
A vast number of apicobasal polarity proteins play essential roles in the polarization and morphogenesis of the neuroepithelia. Crumbs (Crb) type I transmembrane cell-cell adhesion proteins are among these proteins. Five crb genes have been identified in zebrafish. However, their expressional and functional differences during early neural development remain to be fully elucidated. Here, we study the spatial-temporal expression patterns and functions of Crb1, Crb2a, and Crb2b in the central nervous system (CNS) during the neurulation period. We show that: 1, the optic vesicle and undifferentiated retinal neuroepithelium only express Crb2a; 2, Crb1 and Crb2a expressions overlap extensively in the undifferentiated neural tube epithelium; 3, Crb2b expression is the weakest of the three and is restricted to the ventral-most regions of the anterior CNS; and 4, Nok and Crb proteins require each other for their apical localization in neuroepithelium. The commencements of Crb1, Crb2a, and Crb2b expressions follow a spatial-temporal spread from anterior to posterior and from ventral to dorsal and lag behind that of adherens junction components, such as ZO-1 and actin bundles. Genetic and morpholino suppression analyses suggest that in regions where these Crb expressions overlap, they are functionally redundant in maintaining apicobasal polarity of the undifferentiated neuroepithelium.
['Zou|Jian|J|', 'Wen|Yi|Y|', 'Yang|Xiaojun|X|', 'Wei|Xiangyun|X|']
D000367:Age Factors D000818:Animals D030801:Animals, Genetically Modified D002490:Central Nervous System D018507:Gene Expression Regulation, Developmental D006162:Guanylate Cyclase D008565:Membrane Proteins D060172:Morpholinos D009419:Nerve Tissue Proteins D015027:Zebrafish D029961:Zebrafish Proteins D062826:Zonula Occludens-1 Protein
Crumbs Nagie oko Apicobasal polarity Crb the central nervous system CNS Neuroepithelium Nok -somite stage -ss Lin7c hours postfertilization hpf