The Mode and Molecular Mechanisms of the Migration of Presumptive PGC in the Endoderm Cell Mass of Xenopus Embryos

Dev Growth Differ. 2005 Jan;47(1):37-48. doi: 10.1111/j.1440-169x.2004.00777.x.


We investigated the mode of migration of presumptive primordial germ cells (pPGC) in the endoderm cell mass of Xenopus embryos at stages 7-40. The molecules underlying the migration were also studied cytochemically and immunocytologically. By examining the relative positions of pPGC and somatic cells derived from the single, fluorescein-dextran lysine (FDL)-injected, germ plasm-bearing cells of stage 6 embryos, pPGC in embryos at stages 7-23 and those at stages later than 24 were assumed to passively and actively migrate in the endoderm cell mass, respectively. This assumption was supported by the observation that F-actin, essential for active cell migration, was recognized on pPGC of the latter stages, but never on those of the former ones. In addition, the molecule like CXC chemokine receptor 4 (CXCR4) found on directionally migrating PGC in mouse and zebrafish, probably Xenopus CXCR4 (xCXCR4), was detected on pPGC only at latter stages. Accordingly, F-actin and xCXCR4, and probably beta1-integrin and collagen type IV, which are indispensable for the formation of F-actin, are thought to be involved in the active migration of pPGC in the endoderm cell mass.

Publication types

  • Comparative Study

MeSH terms

  • Actins / metabolism
  • Animals
  • Cell Movement / physiology*
  • Chromatography, Affinity
  • DNA Primers
  • Embryo, Nonmammalian / metabolism
  • Embryo, Nonmammalian / physiology
  • Endoderm / physiology*
  • Germ Cells / metabolism
  • Germ Cells / physiology*
  • Immunohistochemistry
  • Receptors, CXCR4 / metabolism
  • Xenopus / embryology*


  • Actins
  • DNA Primers
  • Receptors, CXCR4