Evidence for two distinct waves of epidermal ionocyte differentiation during medaka embryonic development. Issue 7 (18th June 2015)

• Record Type: Journal Article
• Authors: Trayer, Vincent; Séjourné, Nina; Gay, Stéphanie; Thermes, Violette
• Is Part Of: Developmental dynamics. Volume 244:Issue 7(2015:Jul.)
• Page Start: 888
• Page End: 902
• Publication Date: 2015-06-18
• Subjects: Morphogenesis -- Periodicals; Anatomy -- Periodicals; Anatomie -- Périodiques; Biologie du développement -- Périodiques; 571.833
• DOI: 10.1002/dvdy.24290
• Languages: English
• ISSNs: 1058-8388

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p> <bold> <underline>Background:</underline> </bold> The fish epidermis contains specific cells, or ionocytes, that are specialized in ion transport and contribute to the osmoregulatory function. Besides the zebrafish model, the medaka (<italic>Oryzias latipes</italic>) has recently emerged as an important model for osmoregulation studies because it possesses a particularly high adaptability to salinity changes. However, hindering the progress of research on embryonic ionocytes is the lack of a comprehensive view of their developmental dynamic. <bold><underline>Results:</underline></bold> Using EdU integrations and the <italic>foxi3</italic> and NKA markers, we characterized the proliferating progenitors of ionocytes (here called ionoblastes) and we quantified them, along with ionocytes, during embryogenesis. While progenitors of the vitellin zone promptly differentiate in a synchronous manner, progenitors of the lateral zone differentiate progressively and asynchronously. Furthermore, we evidenced that <italic>nhe3</italic> is expressed in differentiated ionocytes of both zones, whereas <italic>ecac</italic>, <italic>ncc</italic>, and <italic>gcm2</italic> are strictly specific of the lateral zone. We also evidenced that the two zones are differentially regulated in distilled water and seawater. <bold><underline>Conclusions:</underline></bold> Our data led us to propose a model timeline, which provides evidence for the expansion of two successive and distinct populations of ionocytes. This model opens the way for new studies related to epidermal development, plasticity and osmoregulation ontogeny. <italic>Developmental Dynamics 244:888–902, 2015</italic>. © 2015 Wiley Periodicals, Inc.</p> </abstract>