title: Brachyury null mutant-induced defects in juvenile ascidian endodermal organs.
abstract: We report the isolation of a recessive ENU-induced short-tailed mutant in the ascidian Ciona intestinalis that is the product of a premature stop in the brachyury gene. Notochord differentiation and morphogenesis are severely disrupted in the mutant line. At the larval stage, variable degrees of ectopic endoderm staining were observed in the homozygous mutants, indicating that loss of brachyury results in stochastic fate transformation. In post-metamorphosis mutants, a uniform defect in tail resorption was observed, together with variable defects in digestive tract development. Some cells misdirected from the notochord lineage were found to be incorporated into definitive endodermal structures, such as stomach and intestine.
authors.affiliation: Department of Molecular, Cell and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
authors.forename: Shota
authors.initials: S
authors.lastname: Chiba
authors.forename: Di
authors.initials: D
authors.lastname: Jiang
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Satoh
authors.forename: William C
authors.initials: WC
authors.lastname: Smith
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015415:Biomarkers / Q000378:metabolism; D019070:Cell Lineage; D002938:Ciona intestinalis / Q000166:cytology / Q000254:growth & development*; D004252:DNA Mutational Analysis; D004707:Endoderm / Q000002:abnormalities* / Q000254:growth & development*; D005038:Ethylnitrosourea; D005326:Fetal Proteins / Q000737:chemistry / Q000172:deficiency* / Q000235:genetics; D041981:Gastrointestinal Tract / Q000002:abnormalities / Q000254:growth & development; D008675:Metamorphosis, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D009672:Notochord / Q000166:cytology; D009928:Organ Specificity; D020825:T-Box Domain Proteins / Q000737:chemistry / Q000172:deficiency* / Q000235:genetics; D013623:Tail / Q000002:abnormalities / Q000254:growth & development; D000098908:Brachyury Protein
chemical_list: D015415:Biomarkers; D005038:Ethylnitrosourea; D005326:Fetal Proteins; D020825:T-Box Domain Proteins; D000098908:Brachyury Protein