Brachyury downstream notochord differentiation in the ascidian embryo.
The ascidian tadpole represents the most simplified chordate body plan. It contains a notochord composed of just 40 cells, but as in vertebrates Brachyury is essential for notochord differentiation. Here, we show that the misexpression of the Brachyury gene (Ci-Bra) of Ciona intestinalis is sufficient to transform endoderm into notochord. Subtractive hybridization screens were conducted to identify potential Brachyury target genes that are induced upon Ci-Bra misexpression. Of 501 independent cDNA clones that were surveyed, 38 were specifically expressed in notochord cells. These potential Ci-Bra downstream genes appear to encode a broad spectrum of divergent proteins associated with notochord formation.
Takahashi
H
H
Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Hotta
K
K
Erives
A
A
Di Gregorio
A
A
Zeller
R W
RW
Levine
M
M
Satoh
N
N
D000818:Animals; D002938:Ciona intestinalis / Q000196:embryology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004707:Endoderm / Q000502:physiology; D005326:Fetal Proteins; D015870:Gene Expression; D009672:Notochord / Q000196:embryology*; D020825:T-Box Domain Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D000098908:Brachyury Protein
D004268:DNA-Binding Proteins; D005326:Fetal Proteins; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D000098908:Brachyury Protein