title: Distinct mechanisms control the timing of differentiation of two myeloid populations in Xenopus ventral blood islands.
abstract: Previous study has suggested that distinct populations of myeloid cells exist in the anterior ventral blood islands (aVBI) and posterior ventral blood islands (pVBI) in Xenopus neurula embryo. However, details for differentiation programs of these two populations have not been elucidated. In the present study, we examined the role of Wnt, vascular endothelial growth factor (VEGF) and fibroblast growth factor signals in the regulation of myeloid cell differentiation in the dorsal marginal zone and ventral marginal zone explants that are the sources of myeloid cells in the aVBI and pVBI. We found that regulation of Wnt activity is essential for the differentiation of myeloid cells in the aVBI but is not required for the differentiation of myeloid cells in the pVBI. Endogenous activity of the VEGF signal is necessary for differentiation of myeloid cells in the pVBI but is not involved in the differentiation of myeloid cells in the aVBI. Overall results reveal that distinct mechanisms are involved in the myeloid, erythroid and endothelial cell differentiation in the aVBI and pVBI.
authors.affiliation: Department of Biology, Faculty of Science, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan. maenobio@bio.sc.niigata-u.ac.jp
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Maéno
authors.forename: Kyogo
authors.initials: K
authors.lastname: Komiyama
authors.forename: Yoko
authors.initials: Y
authors.lastname: Matsuzaki
authors.forename: Junichi
authors.initials: J
authors.lastname: Hosoya
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kurihara
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sakata
authors.forename: Yumi
authors.initials: Y
authors.lastname: Izutsu
mesh_terms: D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D022423:Myeloid Cells / Q000166:cytology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism; D014981:Xenopus
chemical_list: D019485:Bone Morphogenetic Proteins; D042461:Vascular Endothelial Growth Factor A; D051153:Wnt Proteins; D005346:Fibroblast Growth Factors