title: The role of Xmsx-2 in the anterior-posterior patterning of the mesoderm in Xenopus laevis.
abstract: Many molecules are involved in defining mesodermal patterning of the Xenopus embryo. In this paper, evidence is provided that a member of the msx family of genes, the Xmsx-2 gene, is involved in anterior-posterior patterning of the mesoderm. A comparison of its sequence to another previously cloned msx-2 Xenopus homolog, Xhox-7.1' [45] showed that they are closely related. The Xmsx-2 gene is first expressed at midgastrulation predominantly in the dorsal part of the embryo. It showed a complex pattern of spatial expression, consistent with a role in patterning of the anterior-posterior axis. This inference is confirmed by gain-of-function experiments in which overexpressed msx-2 mRNA in developing Xenopus embryos resulted in embryos lacking anterior structures. Analysis of markers in mutant embryos showed that genes involved in ventral-posterior patterning such as Xhox-3, Xwnt-8, and Xvent-1 were upregulated, confirming the posteriorized nature of the embryos. We believe that the Xmsx-2 gene is involved in refining the patterning of the anterior-posterior part of the dorsal mesoderm after the initial signals determining the dorsal or ventral nature of the mesoderm have been specified.
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor 48109-1078, USA. sggong@umich.edu
authors.forename: S G
authors.initials: SG
authors.lastname: Gong
authors.forename: A
authors.initials: A
authors.lastname: Kiba
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015415:Biomarkers; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000648:ultrastructure; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics; D008648:Mesoderm / Q000502:physiology*; D008845:Microinjections; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000008:administration & dosage / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D051153:Wnt Proteins; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics; D029961:Zebrafish Proteins
chemical_list: D015415:Biomarkers; D004268:DNA-Binding Proteins; C094040:EVX1 protein, Xenopus; D018398:Homeodomain Proteins; C084119:MSX2 protein; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D051153:Wnt Proteins; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; C112507:ventx1.2 protein, Xenopus; C495248:wnt8a protein, Xenopus