... progenitor domain (OEPD) is induced by Fgf signaling in a Foxi1- and Dlx3b/4b-dependent manner, but the functional differences of Foxi1 and Dlx3b/4b in subsequent cell fate specifications within the developing inner ear are poorly understood. Based on pioneer tracking (PioTrack), a novel Cre-dependent...

... origins in different tissues. Excess RA leads to ectopic foxi1 expression throughout the entire preplacodal domain. Foxi1 provides competence to adopt an otic fate. Subsequently, pax8 , the expression of which depends upon Foxi1 and Fgf, is also expressed throughout the preplacodal domain. By contrast...

... that zebrafish embryos mutant for fgf3 and fgf8 do not express early EB placode markers, including foxi1 and pax2a . Mosaic analysis demonstrates that placodal cells must directly receive Fgf signals during a specific crucial period of development. Transplantation experiments and mutant analysis reveal...

... developmental periods, first in the preotic placode and later in the otic vesicle. Interactions with the Notch pathway confirm that atoh1 genes have early proneural function. Fgf3 and Fgf8 are upstream activators of atoh1 genes during both phases,and foxi1, pax8 and dlx genes regulate atoh1b in the preplacode...

... in the endodermal pouches. Furthermore, ectopic fgf3 expression is sufficient for inducing phox2a -positive neurons in wild-type and endoderm-deficient embryos. Surprisingly, ectodermal foxi1 expression, a marker for the epibranchial placode precursors, is present in both endoderm-deficient embryos and fgf3...

... of Fgf signals. Our results further provide evidence that pax8 expression and pax2a expression are regulated by two independent factors, Foxi1 and Dlx3b, respectively. Combined loss of both factors eliminates all indications of otic specification. We suggest that the Foxi1-Pax8 pathway provides an early...

... ). A phylogenetic tree of the Wnt genes based on all available full-length sequences, including five from the cephalochordate Amphioxus. Mol. Biol. Evol. 17 , 1896 -1903. Solomon, K. S., Kudoh, T., Dawid, I. G. and Fritz, A. ( 2003 ). Zebrafish foxi1 mediates otic placode formation and jaw development...

... their development is not well understood. Here we report that the zebrafish mutation no soul , in which epibranchial placodes are defective, disrupts the fork headrelated, winged helix domain-containing protein Foxi1. Foxi1 is expressed in lateral placodal progenitor cells. In the absence of foxi1 activity...

... placodes and mutant embryos show a dorsoventral (DV)cartilage defect manifested as a reduced hyomandibular and reduced third and fourth branchial arches. We identified foxi one ( foo ), the zebrafish ortholog of Foxi1 (FREAC6, FKHL10, HFH-3, Fkh10) and a member of the forkhead domain transcriptional...

...Malin Hulander; Amy E. Kiernan; Sandra Rodrigo Blomqvist; Peter Carlsson; Emma-Johanna Samuelsson; Bengt R. Johansson; Karen P. Steel; Sven Enerbäck Mice that lack the winged helix/forkhead gene Foxi1 (also known as Fkh10 ) are deaf and display shaker/waltzer behavior, an indication of disturbed...

... otic primordia. Here, we identify a mutation in zebrafish, hearsay , which disrupts the initiation of placode formation. We show that hearsay disrupts foxi1 , a forkhead domain-containing gene, which is expressed in otic precursor cells before placodes become visible; foxi1 appears to be the earliest...