title: Long-term culture of Xenopus presumptive ectoderm in a nutrient-supplemented culture medium.
abstract: Animal cap assay is a useful experimental model for investigating the activity of inducers in amphibian development. This assay has revealed that activin A is a potent mesoderm-inducing factor. However, it has been very difficult to induce highly differentiated tissues such as cartilage in a 3-4 day culture period. It was recently reported that jaw cartilage was induced in vitro in an animal cap that had been cultured for 14 days in Steinberg's solution using the sandwich culture method and activin A. Under these conditions, necrosis was occasionally observed in the explants. In this study, we have achieved long-term animal cap cultures in a nutrient-supplemented culture medium designated RDX. This medium was made by modifying the saline concentration of the RD medium previously developed as a basal medium for the serum-free culture of various kinds of mammalian cells. The explants cultured in RDX grew more vigorously compared with those in Steinberg's solution. RDX medium promoted a wider variety of tissue induction and gene expression in the animal caps than Steinberg's solution, and also increased the frequency of cartilage induction. Therefore, the supplemental nutrients may support and promote the differentiation of cartilage. This long-term culture method using RDX medium is useful for studying the differentiation of tissues or organs such as cartilage in vitro.
authors.affiliation: Department of Molecular Oral Medicine and Maxillofacial Surgery, Division of Frontier Medical Science, Graduate School of Biomedical Sciences, Hiroshima University, 734-8553, Japan.
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Fukui
authors.forename: Miho
authors.initials: M
authors.lastname: Furue
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Myoishi
authors.forename: J Denry
authors.initials: JD
authors.lastname: Sato
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Okamoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
mesh_terms: D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000196:embryology; D002454:Cell Differentiation; D002478:Cells, Cultured; D003470:Culture Media / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004475:Ectoderm / Q000166:cytology*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000502:physiology; D066298:In Vitro Techniques; D007568:Jaw / Q000196:embryology; D008858:Microscopy, Phase-Contrast; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014018:Tissue Distribution; D029867:Xenopus Proteins / Q000502:physiology; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D003470:Culture Media; C081825:Distal-less protein-1, Xenopus; D018398:Homeodomain Proteins; D029867:Xenopus Proteins; D004247:DNA