Foxj1 transcription factors are master regulators of the motile ciliogenic program

Abstract

Motile cilia induce fluid movement through their rhythmic beating activity. In mammals, the transcription factor Foxj1 has been implicated in motile cilia formation. Here we show that a zebrafish Foxj1 homolog, foxj1a, is a target of Hedgehog signaling in the floor plate. Loss of Foxj1a compromises the assembly of motile cilia that decorate floor plate cells. Besides the floor plate, foxj1a is expressed in Kupffer's vesicle and pronephric ducts, where it also promotes ciliary differentiation. We show that Foxj1a activates a constellation of genes essential for motile cilia formation and function, and that its activity is sufficient for ectopic development of cilia that resemble motile cilia. We also document that a paralogous gene, foxj1b, is expressed in the otic vesicle and seems to regulate motile cilia formation in this tissue. Our findings identify a dedicated master regulatory role for Foxj1 in the transcriptional program that controls the production of motile cilia.

ERK7 regulates ciliogenesis by phosphorylating the actin regulator CapZIP in cooperation with Dishevelled

“…Thus, we examined the regulation of ERK7 expression. FoxJ1, one of the forkhead family genes, is a master regulator of the motile ciliogenic programme 12,25 , and its spatial expression pattern 12,26 is very similar to that of ERK7. In addition, we noticed that in the deposited microarray data 12 , ERK7 was among the genes that were upregulated by the injection of FoxJ1 under the condition of ectopic expression of a Notch intracellular domain (NICD), which caused a loss of MCCs in the skin 14 .…”

mab21-l3 regulates cell fate specification of multiciliate cells and ionocytes

“…The expression was first detected in the presumptive ectoderm in the animal region at the early gastrula stage (stage 10.5), and became restricted to the ventral ectoderm with a spotted pattern at the late gastrula stage (stage 12/13). At neurula and tailbud stages (stage [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], mab21-l3 is expressed in the epidermis with a salt-and-pepper pattern.…”

“…Cell fate specifications of MCCs and ionocytes are known to be suppressed by the Notch pathway in various developing epithelia [5][6][7][8][9][10][11][12][13][14] . However, MCCspecific and ionocyte-specific transcriptional programmes are governed by different master regulators: a coiled-coil protein multicilin 15 and a forkhead transcription factor foxj1 (refs [16][17][18] for MCCs and another forkhead transcription factor foxi1 (refs 7-9,19-21) for ionocytes. This raises the possibility that an unidentified common regulator(s) links the Notch pathway to both MCC and ionocyte specifications.…”

Contrôle transcriptionnel des gènes ciliaires

“…Deux études montrent également un défaut de formation et de motilité des cils du noeud embryonnaire [24,25]. Chez le poisson zèbre, la diminution d'expression de foxj1a induit l'absence ou la réduction de la taille des cils mobiles présents dans la vésicule de Kupffer et le plancher du tube neural [26,27]. Des défauts ciliaires similaires sont observés chez le xénope dans diffé-rentes régions lorsque l'expression de foxj1 est diminuée (Tableau I) [28].…”