...Evan M. Ratzan; Anne M. Moon; Michael R. Deans ABSTRACT FGF8 signaling plays diverse roles in inner ear development, acting at multiple stages from otic placode induction to cellular differentiation in the organ of Corti. As a secreted morphogen with diverse functions, Fgf8 expression is likely...

... provided that the original work is properly attributed. Epithelial morphogenesis Fgf8 Pharyngeal pouches Tbx1 Wnt11r Zebrafish From the embryonic endoderm emerge a number of epithelial outpocketings that generate the initial anlagen of diverse organs. In the head, these include a series...

...Sandeep Kumar; Gregg Duester Retinoic acid (RA) generated in the mesoderm of vertebrate embryos controls body axis extension by downregulating Fgf8 expression in cells exiting the caudal progenitor zone. RA activates transcription by binding to nuclear RA receptors (RARs) at RA response elements...

... identified by characteristic gene expression were expanded, and caudal domains diminished. A similar shift occurs when fibroblast growth factor (FGF) 8 is increased at the rostral telencephalic organizer, yet the FGF8 source was unchanged in hem-ablated brains. Rather we found that hem WNT or BMP signals...

... signalling centre responsible for patterning mesencephalic and metencephalic regions of the vertebrate brain. Formation and maintenance of the MHB is characterised by a hierarchical program of gene expression initiated by fibroblast growth factor 8 ( Fgf8 ), coupled with cellular morphogenesis, culminating...

...Jirouta Kitagaki; Yutaka Ueda; Xuan Chi; Nirmala Sharma; Cynthia M. Elder; Erika Truffer; Frank Costantini; Mark Lewandoski; Alan O. Perantoni During development of the urogenital tract, fibroblast growth factor 8 ( Fgf8 ) is expressed in mesonephric tubules, but its role in this tissue remains...

... into cholinergic neurons in the basal forebrain nuclei projecting to the cortex. Experiments with Tbr1 knockout mice, which lack ventropallial structures, confirmed the pallial origin of cholinergic neurons in Meynert and horizontal diagonal band nuclei. Also, we demonstrate that Fgf8 signaling...

... the MHB. The MHB organizer gene Fgf8 , which is expressed as a sharp transverse band immediately posterior to the lineage boundary at the MHB, is crucial in maintaining the lineage-restricted boundary after E7.5. Partial deletion of Fgf8 disrupts MHB lineage separation. Activation of FGF pathways has...

...) patterning in the neocortical area map. Whether FGF8 controls patterning as a classic diffusible morphogen has not been directly tested. We report evidence that FGF8 diffuses through the mouse neocortical primordium from a discrete source in the anterior telencephalon, forms a protein gradient across...

... malformations, hypoplastic pulmonary and aortic arch arteries, cardiac malformations, micrognathia, thymus hypoplasia and mislocalization of the parathyroid gland. In a heterozygous Fgf8 or Tbx1 genetic background, ectopic activation of Wnt—β-catenin signaling caused an increased incidence and severity of DGS...

... genes are required to ensure that folia exclusive to the vermis or hemispheres form in the appropriate mediolateral position. Furthermore, En1/En2 continue to regulate foliation after embryonic day 14, at which time Fgf8 isthmic organizer activity is complete and the major output cells of the cerebellar...

...Ashley W. Seifert; Terry Yamaguchi; Martin J. Cohn In mammalian embryos, male and female external genitalia develop from the genital tubercle. Outgrowth of the genital tubercle is maintained by the urethral epithelium, and it has been reported that Fgf8 mediates this activity. To test directly...

... -deficient cells is sufficient to induce surrounding wild-type epithelial and mesenchymal cells to participate in the formation of new teeth. Strikingly, Msx1 , which is necessary for endogenous tooth development, is dispensable for supernumerary tooth formation. In addition, we identify Fgf8 , a known tooth...

... reduced. It has been suggested that Foxg1 acts by positively regulating the expression of growth factors, such as Fgf8, which support neurogenesis. However, Foxg1 also binds Smad transcriptional complexes, allowing it to negatively regulate the effects of TGFβ family ligands. Here, we provide evidence...

... the novel skeletogenic capacity of a structure mostly known for its role in olfactory neurogenesis. We showed that replacing the olfactory placodal epithelium with an FGF8-soaked bead was sufficient to completely rescue the skeleton. We favor the explanation that FGF8 stimulated the proliferation...

... is absent in invertebrates such as Drosophila . The Fgf8 signaling molecule expressed in the MHB organizer plays a key role in delineating separate mesencephalon and metencephalon compartments in the vertebrate CNS. Here, we present evidence that an Fgf8 ortholog establishes sequential patterns...

... primed by Bmp antagonists. * Author for correspondence (e-mail: [email protected] ) 2 10 2008 © 2008. 2008 Fgf8 Wnt8 Bmp Neural crest Induction Xenopus The neural crest (NC) is a population of cells unique to the vertebrate embryo. NC progenitors originate from...

... (presumptive thalamus) and p3, along its longitudinal axis. Besides the local expression of signaling molecules such as sonic hedgehog ( Shh ), Wnt proteins and Fgf8, the patterning mechanisms of the thalamic nuclei are largely unknown. Using mouse in utero electroporation to overexpress or inhibit endogenous...

... of the aforementioned three tissue layers in early androgen-independent GT development. WNT-β-catenin signaling is required in the endodermal urethra to activate and maintain Fgf8 expression and direct GT outgrowth, as well as to maintain homeostasis of the urethra. Moreover, β-catenin is required in the mesenchyme...

... source of Shh to the presumptive BA1 territory. Grafting quail fibroblasts engineered to produce Shh (QT6-Shh), at the 5- to 8-somite stage, resulted in the induction of mirror-image extra lower jaws, caudolateral to the normal one. It turns out that the oral opening epithelium, in which Shh, Fgf8...