title: Ledgerline, a novel Xenopus laevis gene, regulates differentiation of presomitic mesoderm during somitogenesis.
abstract: Segmentation of the vertebrate body via the sequential formation of somites is an important process in embryogenesis. This sequential process is governed by the activation and regulation of Notch-related molecular oscillators by fibroblast growth factor and retinoic acid (RA) signaling. In this study, we identified ledgerline, a novel gene of Xenopus laevis expressed specifically in the presomitic mesoderm. Knockdown of ledgerline using antisense morpholino oligonucleotides shifted the developing somite front and altered the expression of genes that regulate molecular oscillation, including Delta2, ESR5, Hairy2a, and Thylacine1. Knockdown of ledgerline also downregulated RALDH-2 expression. Injection of RARalpha-CA, a constitutively active mutant of the RA receptor RARalpha, subsequently reduced the altered Thylacine1 expression. These results strongly suggest that ledgerline is essential for mesodermal RA activity and differentiation of the presomitic mesoderm during Xenopus somitogenesis.
authors.affiliation: International Cooperative Research Project by JST (Japan Science and Technology Agency), Graduate School of Arts and Sciences, The University of Tokyo, Japan.
authors.forename: Techuan
authors.initials: T
authors.lastname: Chan
authors.forename: Reiko
authors.initials: R
authors.lastname: Satow
authors.forename: Hirochika
authors.initials: H
authors.lastname: Kitagawa
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Kato
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D002454:Cell Differentiation / Q000502:physiology*; D018076:DNA, Complementary; D004815:Epidermal Growth Factor; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization / Q000662:veterinary; D008648:Mesoderm / Q000502:physiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000662:veterinary; D051880:Receptors, Notch / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014212:Tretinoin / Q000378:metabolism*; D029867:Xenopus Proteins / Q000235:genetics* / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D051880:Receptors, Notch; D029867:Xenopus Proteins; D014212:Tretinoin; D004815:Epidermal Growth Factor