New roles for FoxH1 in patterning the early embryo.
FoxH1 (Fast1) was first characterized as the transcriptional partner for Smad proteins. Together with Smad2/4, it forms the activin response factor (ARF) that binds to the Mix.2 promoter in Xenopus embryos. Foxh1 is expressed maternally in Xenopus. Depletion of maternal Foxh1 mRNA results in abnormalities of head and dorsal axis formation. We show that FoxH1 is required, together with XTcf3/beta catenin, to activate the zygotic expression of the nodal gene, Xnr3 in a Smad2-independent manner. In contrast, maternal FoxH1 acts as an inhibitor of Xnr5 and 6 transcription, preventing their upregulation on the ventral side of the embryo, by the maternal T-box transcription factor VegT. We conclude that maternal FoxH1 has essential, context-dependent roles in regulating the pattern of zygotic gene expression in the early embryo.
Division of Developmental Biology, Cincinnati Children's Research Foundation, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
Matt
M
Kofron
Helbert
H
Puck
Henrietta
H
Standley
Chris
C
Wylie
Robert
R
Old
Malcolm
M
Whitman
Janet
J
Heasman
D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D005260:Female; D051858:Forkhead Transcription Factors; D017930:Genes, Reporter; D006257:Head / Q000196:embryology; D055457:Nodal Protein; D055456:Nodal Signaling Ligands; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014981:Xenopus; D029867:Xenopus Proteins / Q000378:metabolism
D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; C491117:Foxh1 protein, mouse; D055457:Nodal Protein; D055456:Nodal Signaling Ligands; C526008:Nodal protein, mouse; D012333:RNA, Messenger; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; C094620:nodal3.1 protein, Xenopus; C418882:nodal5 protein, Xenopus; C418883:nodal6 protein, Xenopus