... that they also share gene expression profiles with vertebrate anterior neural tissue and cranial placodes, their study should shed light on the emergence of the unique vertebrate telencephalon. We show that BMP signaling regulates two phases of palp formation in Ciona intestinalis . During gastrulation...

...Eleonora Conti; Oliver Harschnitz ABSTRACT Placodes are embryonic structures originating from the rostral ectoderm that give rise to highly diverse organs and tissues, comprising the anterior pituitary gland, paired sense organs and cranial sensory ganglia. Their development, including...

...Aditi Dubey; Jianshi Yu; Tian Liu; Maureen A. Kane; Jean-Pierre Saint-Jeannet ABSTRACT All paired sensory organs arise from a common precursor domain called the pre-placodal region (PPR). In Xenopus , Zic1 non-cell autonomously regulates PPR formation by activating retinoic acid (RA) production...

... that this non-neural origin of pineal progenitors is conserved in amniotes. Genetic repression of placodal, but not neural crest, cell fate results in pineal hypoplasia in zebrafish, while mis-expression of transcription factors known to specify placodal identity during gastrulation promotes the formation...

... of Biologists Ltd 2017 Summary: This Review presents current knowledge of the development of the sensory microdomains in mammalian skin and the mechanosensory neurons that innervate them. Touch Skin Hair follicle Merkel cell Placode Axon guidance Like all senses, the sense of touch...

...Jingchen Chen; Monica Tambalo; Meyer Barembaum; Ramya Ranganathan; Marcos Simões-Costa; Marianne E. Bronner; Andrea Streit The inner ear is a complex vertebrate sense organ, yet it arises from a simple epithelium, the otic placode. Specification towards otic fate requires diverse signals...

.... , Renvoisé , E. , Shirokova , V. , Vartiainen , M. K. , Thesleff , I. and Mikkola , M. L. ( 2014 ). Directional cell migration, but not proliferation, drives hair placode morphogenesis . Dev. Cell   28 , 588 - 602 . 10.1016/j.devcel.2014.02.003 Arwert , E. N. , Hoste , E...

...Philip Tomann; Ralf Paus; Sarah E. Millar; Claus Scheidereit; Ruth Schmidt-Ullrich ABSTRACT In the epidermis of mice lacking transcription factor nuclear factor-kappa B (NF-κB) activity, primary hair follicle (HF) pre-placode formation is initiated without progression to proper placodes. NF-κB...

...Jingjing Li; Lemonia Chatzeli; Eleni Panousopoulou; Abigail S. Tucker; Jeremy B. A. Green Ectodermal organs, which include teeth, hair follicles, mammary ducts, and glands such as sweat, mucous and sebaceous glands, are initiated in development as placodes, which are epithelial thickenings...

... scutes. Studies of turtle development have mostly focused on the bones of the shell; however, the genetic regulation of the epidermal scutes has not been investigated. Here, we show that scutes develop from an array of patterned placodes and that these placodes are absent from a soft-shelled turtle...

... governing morphogenesis of the palps. It is conceivable that Islet is also essential for the cellular morphogenesis of placode-derived sensory neurons in vertebrates. * Author for correspondence ( mlevine@berkeley.edu ) Competing interests The authors declare no competing financial interests...

...Tatsuro Ikeda; Terumi Matsuoka; Yutaka Satou The ascidian larval brain and palps (a putative rudimentary placode) are specified by two transcription factor genes, ZicL and FoxC , respectively. FGF9/16/20 induces ZicL expression soon after the bi-potential ancestral cells divide into the brain...

...Sabine Freter; Stephen J. Fleenor; Rasmus Freter; Karen J. Liu; Jo Begbie The majority of cranial sensory neurons originate in placodes in the surface ectoderm, migrating to form ganglia that connect to the central nervous system (CNS). Interactions between inward-migrating sensory neuroblasts...

... in early-branching metazoan species remains poorly understood. Here we demonstrate that three fundamental processes contribute to embryonic tentacle development in the cnidarian Nematostella vectensis . First, a pseudostratified ectodermal placode forms at the oral pole of developing larvae...

... and Pax8 modulate commitment and behavior in cells that eventually contribute to the otic vesicle and epibranchial placodes. Initially, a subset of epibranchial placode precursors lie lateral to otic precursors within a single Pax2a/8-positive domain; these cells subsequently move to segregate...

...Eileen Wagner; Michael Levine The Ciona tadpole is constructed from simple, well-defined cell lineages governed by provisional gene networks that have been defined via extensive gene disruption assays. Here, we examine the patterning of the anterior neural plate, which produces placodal derivatives...

... that the RA- Hox1 network also functions in the epidermal ectoderm of chordates. Here, we show that in the urochordate ascidian Ciona intestinalis , RA- Hox1 in the epidermal ectoderm is necessary for formation of the atrial siphon placode (ASP), a structure homologous to the vertebrate otic placode. Loss...

... common precursor domain: the posterior placodal area. This review summarises recent studies into the induction, morphogenesis and innervation of these systems and discusses lineage restriction and cell specification in the context of their common origin. References Abelló G. , Khatri S...

...Celia E. Shiau; Marianne Bronner-Fraser Vertebrate cranial sensory ganglia have a dual origin from the neural crest and ectodermal placodes. In the largest of these, the trigeminal ganglion, Slit1-Robo2 signaling is essential for proper ganglion assembly. Here, we demonstrate a crucial role...

...Crestina L. Beites; Piper L. W. Hollenbeck; Joon Kim; Robin Lovell-Badge; Arthur D. Lander; Anne L. Calof The regenerative capacity of many placode-derived epithelial structures makes them of interest for understanding the molecular control of epithelial stem cells and their niches. Here, we...