Xotx5b, a new member of the Otx gene family, may be involved in anterior and eye development in Xenopus laevis.
We describe the cloning, expression pattern and functional overexpression analysis of Xotx5b, a new member of the Otx gene family in Xenopus laevis. Early expression of Xotx5b resembles that of Xotx2, being detected in the organizer region at early gastrula stage, and, shortly after, also in anterior neuroectoderm. During neurula stages Xotx5b exhibits a changing and dynamic pattern of expression. After neural tube closure, Xotx5b is expressed in the eye and pineal gland, both involved in photoreception. Overexpression of Xotx5b has a similar effect to that of Xotx2, producing posterior truncations and inducing ectopic cement gland and neural tissue in whole embryos. In animal cap assays, Xotx5b and Xotx2 are both able to activate XAG, to strongly suppress the expression of the epidermal marker XK81, and to reciprocally activate each other. Finally, in einsteck transplantation assays, Xotx5b is able to respecify a tail/trunk organizer to a head organizer.
Vignali
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Laboratori di Biologia Cellulare e dello Sviluppo, Dipartimento di Fisiologia e Biochimica, Università di Pisa, Via G. Carducci 13, 56010 Ghezzano, Pisa, Italy. rvignali@dfb.unipi.it
Colombetti
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S
Lupo
G
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Zhang
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W
Stachel
S
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Harland
R M
RM
Barsacchi
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015415:Biomarkers; D003001:Cloning, Molecular; D005123:Eye / Q000196:embryology*; D005775:Gastrula / Q000378:metabolism; D015723:Gene Library; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D017403:In Situ Hybridization; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009432:Neural Crest / Q000378:metabolism; D051857:Otx Transcription Factors; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism / Q000494:pharmacology; D013997:Time Factors; D014018:Tissue Distribution; D015534:Trans-Activators / Q000096:biosynthesis; D014981:Xenopus / Q000196:embryology* / Q000235:genetics; D029867:Xenopus Proteins
D015415:Biomarkers; C416212:CRX protein, Xenopus; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D051857:Otx Transcription Factors; C497661:Otx2 protein, Xenopus; D012333:RNA, Messenger; D015534:Trans-Activators; D029867:Xenopus Proteins; C499607:Xotx5 protein, Xenopus