ライフサイエンスコーパス: Placode

1 it arises from a simple epithelium, the otic placode.

2 ectodermal cells that give rise to the lens placode.

3 ved in the initial specification of the otic placode.

4 ired for the formation of the posterior otic placode.

5 produced supernumerary Type II NBs from the placode.

6 lar proliferation in the embryonic olfactory placode.

7 st neurogenic events in the developing nasal placode.

8 f cells comprising an invaginated epithelial placode.

9 ls the onset of Sox10 expression in the otic placode.

10 els of Fgfr1, Bmp4 and Otx2 in the olfactory placode.

11 r cell population for the inner ear, or otic placode.

12 ized region of head ectoderm termed the otic placode.

13 ulator of the sensory neuron fate in the opV placode.

14 kened patch of head ectoderm called the otic placode.

15 r when WNT responses are blocked in the otic placode.

16 ocus on the zebrafish posterior lateral line placode.

17 he embryonic ectoderm called cranial sensory placodes.

18 ations, the neural crest and cranial sensory placodes.

19 l morphology, number and position of mammary placodes.

20 tely generating the neural crest and cranial placodes.

21 and neuroblast delamination in the differing placodes.

22 Sostdc1) in mammary and other skin appendage placodes.

23 tribute to the otic vesicle and epibranchial placodes.

24 etence factors nor does it rescue individual placodes.

25 ia develop from special regions, the cranial placodes.

26 uding markers of cranial neural crest and of placodes.

27 system, neural crest, epidermis and sensory placodes.

28 om either the neural crest or the neurogenic placodes.

29 subsequently move to segregate into distinct placodes.

30 e development of NC, PPE and some individual placodes.

31 roliferation and initiation of hair follicle placodes.

32 ryonic origins, the neural plate and sensory placodes.

33 functions needed for development of specific placodes.

34 neurons, ttll4 in muscle, and ttll7 in otic placodes.

35 ral nervous system (neural plate) or sensory placodes.

36 n the central nervous system and the cranial placodes.

37 ampullary organs, develop from lateral line placodes.

38 n is initiated without progression to proper placodes.

39 nd mammary glands begin their development as placodes.

40 om the emergence of neural crest and cranial placodes.

41 all normally positioned and ectopic mammary placodes.

42 ural plate whereas the head mesoderm induces placodes.

43 of the various cell types that develop from placodes.

44 les in the formation and patterning of taste placodes.

45 signaling in the trigeminal ophthalmic (opV) placode, a prime model of sensory neurogenesis.

46 The otic placode, a specialized region of ectoderm, gives rise to

47 Notch pathway genes in the chick trigeminal placode, a stage-specific expression analysis was conduc

48 tebrates, the inner ear arises from the otic placode, a thickened swathe of ectoderm that invaginates

49 model, we have uncovered evidence that lens placode AC may be partially dependent on apically positi

50 rentiation in the ectoderm of the trigeminal placodes after experimental manipulation of a molecular

51 the activation of FoxC and ZicL in the palp placode and anterior neural tube, respectively.

52 ocation of Shh ligand-expressing cells, from placode and apical papilla cells to taste bud cells only

53 he path of migratory neuroblasts between the placode and CNS in both chick and mouse.

54 , we co-isolate embryonic hair follicle (HF) placode and dermal condensate cells, precursors of adult

55 related to those derived from the olfactory placode and hypothalamic neurons of vertebrates.

56 hormone (GnRH) neurons are born in the nasal placode and migrate along olfactory and vomeronasal axon

57 These neurons originate in the nasal placode and migrate during embryonic development, in ass

58 s originate outside the CNS in the olfactory placode and migrate into the CNS, where they become inte

59 se neurons originate prenatally in the nasal placode and migrate into the forebrain along the olfacto

60 m its initial onset in the invaginating otic placode and onwards throughout gestation, controlling Fg

61 g cell divisions are enriched in the forming placode and that stratification is cell division depende

62 strate that both the enlargement of the otic placode and the expansion of the Wnt8a expression domain

63 ication of neural fates from this neurogenic placode and the fly retina.

64 into restricted lineages including the lens placode and the oral ectoderm (pituitary precursor) cell

65 of ectoderm first thickens to form the lens placode and then invaginates to form the lens pit.

66 tion of thickened dermis, enlarged epidermal placodes and dermal condensates that result in premature

67 progenitors for neural plate, neural crest, placodes and epidermis.

68 nsory cells emerge from the presumptive otic placodes and give rise to hair cells bearing stereocilia

69 rowth factor 20 (Fgf20) is expressed in hair placodes and is induced by and functions downstream from

70 dentify specific defects in the epibranchial placodes and neural crest, which contribute sensory neur

71 ed cell death beyond that seen in Fgfr2(CKO) placodes and prevented lens formation.

72 red for patterned induction of hair follicle placodes and subsequent Wnt signaling in placode stem ce

73 at scutes develop from an array of patterned placodes and that these placodes are absent from a soft-

74 s are not entirely resolved, vertebrate otic placodes and tunicate atrial siphon primordia are though

75 ix1 and its co-activator Eya1, develops into placodes and ultimately into many cranial sensory organs

76 or otic identity between the 10 somite (otic placode) and 20 somite (early otic vesicle) stages.

77 eighbouring cells express neurog1 inside the placode, and apical symmetric divisions amplify the spec

78 ration of cells into the mesenchyme from the placode, and extension of axons by the olfactory sensory

79 y organ formation by elongating lateral line placodes, and even of other zebrafish lateral line placo

80 develop from the neural crest and neurogenic placodes, and have been studied as a principal model of

81 sociates with membrane beta-catenin in early placodes, and its continued expression correlates with l

82 ssed in tissues such as the brain, olfactory placodes, and pronephric ducts.

83 ated between three and five pairs of mammary placodes anterior to the first wild-type mammary rudimen

84 tiation of tongue formation, through papilla placode appearance and taste papilla development.

85 The neurogenic cranial placodes are a unique transient epithelial niche of neur

86 n array of patterned placodes and that these placodes are absent from a soft-shelled turtle in which

87 Vertebrate cranial placodes are crucial contributors to the vertebrate cran

88 Cranial placodes are evolutionary innovations of vertebrates.

89 assignments between vertebrate and tunicate placodes are not entirely resolved, vertebrate otic plac

90 These placodes are stratified into a basal and several supraba

91 The neural crest and craniofacial placodes are two distinct progenitor populations that ar

92 Although placodes are ubiquitous precursors of tissue invaginatio

93 Conditional deletion of Sox2 in the lens placode arrests lens development at the pit stage.

94 or the onset of Sox10 expression in the otic placode, as opposed to Myb plus Sox9 and Ets1 for neural

95 These placodes, as well as the neural crest, arise from a zone

96 ORs were first detected in the placode at embryonic day 9 (E9), at the onset of OSN dif

97 on is detectable by E12.5, when the CV taste placode begins to form.

98 ellular actomyosin cable in the cells at the placode border, with myosin II accumulating at edges whe

99 of AJ component E-cadherin is important for placode budding in mice.

100 In mice, hair follicle placode "budding" is initiated by invagination of Wnt-in

101 initially elevated in the invaginating lens placode, but by the lens vesicle stage, ERK phosphorylat

102 subpopulations of neurons emerging from the placode by embryonic day (E)10, a time at which the migr

103 neural plate, and a precursor field for the placodes, called the pre-placodal region (PPR), that lie

104 rturbation in neural crest cells impacts the placode cell contribution to the trigeminal ganglia and

105 test the function of Notch signaling in opV placode cell differentiation, Notch receptor cleavage wa

106 llified the requirement of Egfr activity for placode cell survival.

107 RhoA mutant lens placode cells are both longer and less apically constric

108 By contrast, Rac1 mutant lens placode cells are shorter and more apically restricted t

109 Glypican-1 (GPC1) is expressed by trigeminal placode cells as they ingress and contribute to trigemin

110 Fgfr1/2 conditional knockout placode cells expressed lower levels of proteins known t

111 how that a subset of human invaginating hair placode cells expresses the stem cell marker CD133 durin

112 we review the evidence that neural crest and placode cells remain in close proximity throughout their

113 s of both Notch and Egfr function caused all placode cells to become IPC NBs and survive, indicating

114 ryos contains precursors of neural crest and placode cells, both defining vertebrate characteristics.

115 de formation in Fgfr1/2 conditional knockout placode cells, FGF signaling was functionally absent dur

116 re present at normal levels in the remaining placode cells, including the transcription factors Pax6,

117 Together with epidermally-derived placode cells, neural crest cells then form the cranial

118 ns formation was not altered in the knockout placode cells, we can conclude that FGF signaling from t

119 are derived from both neural crest cells and placode cells.

120 o provide essential survival signals to lens placode cells.

121 rigeminal, epibranchial, otic, and olfactory placodes coincides with detachment of these neuroblasts

122 Taste placodes comprise taste bud precursor cells, which expre

123 In vertebrates, cranial placodes contribute to all sense organs and sensory gang

124 Vertebrate cranial placodes contribute vitally to development of sensory st

125 of neuroectoderm, neural crest (NC), cranial placode (CP), and non-neural ectoderm in multiple hPSC l

126 r the migration of molecularly heterogeneous placode-derived cells in the mesenchyme.

127 ure state of PG precursors emerging from the placode-derived ganglia en route to their terminal targe

128 rent with the interaction between the NC and placode-derived ganglia.

129 is independent of NC apoptosis or defects in placode-derived ganglia.

130 mpullary organs are ancestrally lateral line placode-derived in bony fishes.

131 The coalition of both placode-derived migratory cells and OSN axons within the

132 hypomorph embryos leads to an early loss of placode-derived sensory ganglia and reduced number of NC

133 essential for the cellular morphogenesis of placode-derived sensory neurons in vertebrates.

134 for early NC survival and differentiation of placode-derived sensory neurons, and reveal a novel role

135 In hair follicle development, a placode-derived signal is believed to induce formation o

136 ebrates primitively possessed a lateral line placode-derived system of electrosensory ampullary organ

137 similar to otic placode invagination, but a placode-derived vesicle is never observed as for the oti

138 inned clade of bony fishes) are lateral line placode-derived, non-placodal origins have been proposed

139 Eya1 suggesting new avenues of research into placode development and disease.

140 briefly review our current understanding of placode development and the cell types and structures th

141 t genes with potentially important roles for placode development.

142 ic transcription factors, thus solidifying a placode developmental program.

143 ort of RA, which in turn activates a cranial placode developmental programme in neighbouring cells.

144 ing constrained to a fixed area and the lens placode did not form.

145 al interactions between the neural crest and placodes drives the coordinated morphogenesis that gener

146 of skin appendage development is marked by a placode during embryogenesis.

147 roendocrine cells that are born in the nasal placode during embryonic development and migrate through

148 incisor that developed from a single dental placode, early midfacial narrowing as well as abnormalit

149 ellular origin of the inner ear from sensory placode ectoderm and NECs, and changes the current parad

150 the cranial mesenchyme, overlying olfactory placode/epidermal ectoderm, and underlying neuroepitheli

151 ls and developmental processes that underlie placode evolution and development.

152 We next summarise previous hypotheses of placode evolution, discussing their strengths and caveat

153 s, we build these strands into a scenario of placode evolutionary history and of the genes, cells and

154 catenin activation a day later within Shh(+) placodes, expands taste bud precursors directly, but enl

155 rface ectoderm region that includes the lens placode expressed 12 out of 19 possible Wnt ligands.

156 late, is necessary and sufficient to promote placode fate.

157 get genes with potential roles in priming HF placodes for down-growth.

158 However, we find that otic and epibranchial placodes form at different times and by distinct mechani

159 NC and placodes form at the neural plate border (NPB).

160 eucoraja erinacea, we show that lateral line placodes form both ampullary electroreceptors and mechan

161 re, we test the hypothesis that lateral line placodes form electroreceptors in cartilaginous fishes b

162 ial activation of beta-catenin, before taste placodes form, diverts lingual epithelial cells from a t

163 In mice, Eda regulates mammary placode formation and branching morphogenesis, but the u

164 increased cell death from the initiation of placode formation and concurrent deletion of Fgfr1 enhan

165 in the pharyngeal epithelia can affect both placode formation and neural crest fate.

166 thelial and mesenchymal interactions pattern placode formation and outgrowth.

167 the importance of Pax levels during sensory placode formation and provide a mechanism by which these

168 Pax6 is essential for both lens placode formation and subsequent stages of lens morphoge

169 erm, but did not invaginate, suggesting that placode formation establishes the minimal mechanical req

170 not been established and the requirement of placode formation for subsequent invagination has not be

171 ors of tissue invagination, the mechanism of placode formation has not been established and the requi

172 that the cellular events that accompany lens placode formation in chicken embryos also occur in mouse

173 ptosis was already increased at the onset of placode formation in Fgfr1/2 conditional knockout placod

174 aB) activity, primary hair follicle (HF) pre-placode formation is initiated without progression to pr

175 chicken embryos supported the view that lens placode formation occurs because the extracellular matri

176 We then showed that the failure of lens placode formation when the transcription factor, Pax6 wa

177 e cell crowding, leading to cell elongation (placode formation).

178 in is the primary inductive signal for taste placode formation, followed by taste papilla morphogenes

179 early Wise-independent role in facilitating placode formation.

180 of the signaling activity is achieved during placode formation.

181 ntrols cellular processes important for skin placode formation.

182 face ectoderm was sufficient to explain lens placode formation.

183 lly, it has been presumed that the olfactory placode forms all olfactory sensory neurons.

184 First, a pseudostratified ectodermal placode forms at the oral pole of developing larvae and

185 nd sox3 and support a model whereby the otic placode forms first and induces epibranchial placodes th

186 Amongst posterior placodes, the otic placode forms the inner ear whereas nearby epibranchial

187 g development of the early eye when the lens placode forms the lens pit.

188 been shown to regulate the size of the otic placode from which the cochlea will arise; however, dire

189 By progressive delamination of cells, the placode generated a series of NB identities, including t

190 microarray analysis to identify prospective placode genes that were differentially expressed in cont

191 Multipotent progenitor cells in the otic placode give rise to the specialized cell types of the i

192 gan by embryonic day 14.5, when nascent hair placodes had blood vessels approaching them.

193 ever, the evolutionary origins of neurogenic placodes have remained obscure owing to a paucity of emb

194 tudy of the migrating posterior lateral line placode in zebrafish has yielded a wealth of information

195 ppearance of the neural crest and neurogenic placodes in early branching vertebrates has puzzled biol

196 which develop at mid-gestation as epithelial placodes in the anterior tongue.

197 rity of cranial sensory neurons originate in placodes in the surface ectoderm, migrating to form gang

198 inates development of NC, PPE and individual placodes in zebrafish.

199 on and neuromast formation in this migrating placode, in this cypriniform teleost species.

200 Olfactory and otic placodes, in combination with migratory neural crest ste

201 orporate into the otic epithelium after otic placode induction has occurred.

202 tely separable from its earlier role in otic placode induction.

203 signaling, a prerequisite for hair follicle placode induction.

204 Lrp4 mutant mice displayed a delay in placode initiation and changes in distribution and numbe

205 cific factors transform thickened ectodermal placodes into complex sense organs containing numerous,

206 During embryogenesis, the otic placode invaginates into the head to form the otic vesic

207 Here, we show that placode invagination depends on horizontal contraction o

208 tentially accounting for post-stratification placode invagination to bud stage.

209 from the embryonic day (E)10.5 stage of lens placode invagination to E12.5 lens primary fiber cell di

210 rom the embryonic lens either at the time of placode invagination using the Le-Cre line or after init

211 primordium invagination are similar to otic placode invagination, but a placode-derived vesicle is n

212 anial neural crest (NC) and the epibranchial placode is critical for the formation of parasympathetic

213 ls that accompanies invagination of the lens placode is dependent on Shroom3, a molecule previously a

214 pry1(-)/(-); Spry2(-)/(-) embryos), the otic placode is increased in size.

215 s supernumerary IPC NBs, indicating that the placode is initially a fate equivalence group for the IP

216 We demonstrate that the otic placode is larger due to the recruitment of cells, norma

217 into the lens, cornea and iris, and the eye placode is the sole source of retinal tissue.

218 n Fgf20 mutant mice, a regular array of hair placodes is formed, demonstrating that the epithelial pa

219 es, and even of other zebrafish lateral line placodes, is sparse or non-existent.

220 and lining, derives from cells of the atrial placode itself.

221 shift is required for the invasive growth of placode keratinocytes into the dermis, a crucial step in

222 Dsc isoform expression from Dsc3 to Dsc2 in placode keratinocytes.

223 Lens placodes lacking Fgfr1 and 2 were thinner than in wild-t

224 th early expression in the dental epithelial placode leading to later expression in the dental mesenc

225 tially into non-neural, preplacodal and otic-placode-like epithelia.

226 are the ectodermal cranial neural crest and placode lineages.

227 These rudiments expressed the mammary placode markers Wnt10b and Tbx3 and were labeled by anti

228 Two placode markers, Fgf4 and Foxi3, were down-regulated in

229 ifferentiation of cells within the olfactory placode, migration of cells into the mesenchyme from the

230 regulating the initiation stages of mammary placode morphogenesis, and suggest that this and other H

231 ays a key role in coordinating otic fate and placode morphogenesis, but appears to regulate each proc

232 Placode neurogenesis occurs throughout an extended perio

233 he epithelial cells of the invaginating lens placode normally elongate and change from a cylindrical

234 The enlargement of the otic placode observed in Spry1(-)/(-); Spry2(-)/(-) embryos i

235 al period when neuronal selection within the placodes occurs, and neuroblasts concomitantly delaminat

236 erior (otic, lateral line, and epibranchial) placodes of vertebrates probably evolved from a posterio

237 rior (adenohypophyseal, olfactory, and lens) placodes of vertebrates.

238 o the olfactory progenitors of the embryonic placode (OPPs).

239 that conclusively demonstrate a lateral line placode origin for ampullary organs and neuromasts.

240 but the future central nervous system, while placodes originate in a common preplacodal region slight

241 velopment, these cells are born in the nasal placode outside the brain and migrate in association wit

242 Finally, although Shh regulates taste placode patterning, we find that it is dispensable for t

243 Initially, a subset of epibranchial placode precursors lie lateral to otic precursors within

244 ishing the competence state induces anterior placode precursors.

245 However, neither crest nor placodes produce head muscles, which are a crucial compo

246 ms the inner ear whereas nearby epibranchial placodes produce sensory ganglia within branchial clefts

247 l and associated connective tissues, whereas placodes produce sensory organs.

248 on this analysis we propose a new model for placode progenitor induction, in which the initial induc

249 d (RA) signalling as a key player in cranial placode progenitor specification.

250 ought-after mechanism that initiates Pax6 in placode progenitors and may explain the ancient evolutio

251 All cranial placode progenitors arise from a common precursor field

252 the events that specify ectodermal cells as placode progenitors using newly identified genes upstrea

253 m are required for the formation of anterior placode progenitors, with one of the signals being somat

254 factors begin to impart regional identity to placode progenitors.

255 the prechordal mesendoderm, gradually induce placode progenitors: cells pass through successive trans

256 ated in vitro; however, NCC extension to the placode requires placodal neurogenesis, demonstrating re

257 pr1a caused increased cell death in the lens placode, resulting in the formation of smaller lenses.

258 Though diverse in fate, these placodes show striking similarities in their early regul

259 n the cis-regulatory mechanisms that control placode specification and of how the repeated use of sig

260 signaling, neural crest development, sensory placode specification, ciliogenesis, germ layer specific

261 odermal appendages-as early as the embryonic placode stage-and plays a role in adult appendage functi

262 cle placodes and subsequent Wnt signaling in placode stem cells is essential for induction of dermal

263 gnal exchange between dermal condensates and placode stem cells.

264 or the production of human posterior cranial placodes such as the otic placode that gives rise to the

265 sensory ganglia originating from neurogenic placodes, such as the nodose ganglion, failed to express

266 scription factors Gbx2 and Otx2 patterns the placode territory by influencing regional identity and b

267 posterior cranial placodes such as the otic placode that gives rise to the inner ear do not exist.

268 ent begins with the appearance of epithelial placodes that invaginate, sprout, and branch to form sma

269 Amongst posterior placodes, the otic placode forms the inner ear whereas n

270 n ancestor that possessed cranial neurogenic placodes, thickenings in embryonic head epidermis giving

271 placode forms first and induces epibranchial placodes through an Fgf-relay.

272 romotes morphogenesis in early hair follicle placodes through the localized removal of membrane beta-

273 the differentiation of OSNs in the olfactory placode to an aging olfactory epithelium.

274 migrate and ingress into the epithelialising placode to become the first otic neuronal progenitors.

275 e pre-otic field and restriction of the otic placode to ectoderm adjacent to the hindbrain.

276 ss of Notch function caused all cells of the placode to form as supernumerary IPC NBs, indicating tha

277 ne-1 (GnRH-1) neurons migrate from the nasal placode to the forebrain where they control gonadal func

278 easing hormone (GnRH) neurons from the nasal placode to the hypothalamus, followed by proper synthesi

279 YAP overexpression causes hair placodes to evaginate into epidermis rather than invagin

280 elative contribution of the neural crest and placodes to the otic and olfactory systems.

281 odermal contribution to the developing nasal placode was performed using two complementary mouse mode

282 ck GnRH-1 neurons originate in the olfactory placode, where they are specified shortly after olfactor

283 eltaNp63 is expressed in the developing hair placode, whereas in mature hair its expression is restri

284 pullary organs are derived from lateral line placodes, whereas a neural crest origin has been propose

285 e ganglion are derived from the epibranchial placodes, whereas jugular ganglion neurons are derived f

286 e evidence that Ciona has a neurogenic proto-placode, which forms neurons that appear to be related t

287 n, inner ear precursors elongate to form the placode, which invaginates and is transformed into the c

288 It originates from the otic placode, which invaginates, forming the otic vesicle; th

289 eous glands, are initiated in development as placodes, which are epithelial thickenings that invagina

290 arises from a series of cranial lateral line placodes, which exhibit two modes of sensory organ forma

291 screte patches of surface epithelium, called placodes, which fold into spheroids and undergo complex

292 o form the mammalian brain, while neurogenic placodes, which generate cranial sensory neurons, remain

293 However, proper cranial placodes, which give rise to high density arrays of spec

294 led a common trend throughout the neurogenic placodes, which suggests that both activated FGF and att

295 sing region in the mandible, where the tooth placode will initiate.

296 ate and transcriptionally profile primary HF placodes with active NF-kappaB signaling.

297 opy of morphant zebrafish revealed olfactory placodes with defective morphology as well as pronephric

298 and how they begin to diversify to generate placodes with different identities.

299 way genes and effectors are expressed in the placode, with expression primarily being confined to ect

300 GnRH-1 neurogenesis in the developing nasal placode without affecting proliferation of GnRH-1 neuron