Dissecting the differentiation process of the preplacodal ectoderm in zebrafish. Issue 10 (19th July 2014)

• Record Type: Journal Article
• Authors: Yao, Di; Zhao, Feng; Wu, Ying; Wang, Jialiang; Dong, Wei; Zhao, Jue; Zhu, Zuoyan; Liu, Dong; Mansour, Suzanne L.; Ornitz, David M.
• Is Part Of: Developmental dynamics. Volume 243:Issue 10(2014:Oct.)
• Page Start: 1338
• Page End: 1351
• Publication Date: 2014-07-19
• Subjects: Morphogenesis -- Periodicals; Anatomy -- Periodicals; Anatomie -- Périodiques; Biologie du développement -- Périodiques; 571.833
• DOI: 10.1002/dvdy.24160
• Languages: English
• ISSNs: 1058-8388

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p> <underline>Background:</underline> The preplacodal region (PPR) is a region of specialized ectoderm at the border of neural and nonneural ectoderm (NNE). Coordinated Bmp, Fgf, and Wnt signals are known to drive PPR development; however, the underlying mechanism is unknown. <underline>Results:</underline> We identified key components involved in PPR differentiation. The mesoderm/marginal Wnts at the early gastrula stage trigger differentiation by allowing the adjacent NNE border cells to start adopting caudal PPR fates; otherwise, the development of caudal PPR identity is hindered due to the persistent presence of <italic>gata3</italic> mRNA. The caudal PPR fate dominates when <italic>foxi1</italic> expression is enhanced at the late gastrula stage, and depleting Foxi1 after 6 hours postfertilization (hpf) reduces the otic‐epibranchial placodal domain. When the Gata3 level is manipulated at the fertilized egg stage or near 6 hpf, the lens is always affected. In establishing PPR polarity, both Gata3 and Foxi1 inhibit Bmp signaling, whereas Foxi1 inhibits, but Gata3 enhances, Fgf sensitivity of the PPR cells. <underline>Conclusions:</underline> Our study reveals that in zebrafish, (1) the PPR at the shield stage may enter a developmental state when the PPR cells preferentially adopt a particular placodal fate and (2) a network of genetically linked factors, including Wnt/beta‐catenin, Fgfr, Bmp, Gata3, and Foxi1, direct the process of PPR differentiation. <italic>Developmental Dynamics 243:1338–1351, 2014</italic>. © 2014 Wiley Periodicals, Inc.</p> </abstract>