A Technique for the transfer of primordial germ cells between neurulae of the South African Clawed Toad Xenopus laevis has been described by Blackler & Fischberg (1961). This method was originally developed with the object in mind of eventually making a genetic analysis of abnormal embryos resulting from the transplantation of somatic nuclei. Such analysis involves two schemes which require the transfer of embryonic gonocytes from the defective transplant embryo to a normal recipient. Moreover, one of these two schemes requires that transferred germ cells be reversed in their sexual differentiation in the developing gonad of the host (see Fischberg, 1961; Fischberg & Blackler, 1963a, b).
Since it has been known for some time, from experiments involving parabiosis, transplantation of the gonadal rudiment and hormone treatment (e.g. Burns, 1925, 1930; Witschi, 1937; Humphrey, 1929, 1933, 1948, 1957; Gallien, 1953, 1956), that the manifestation of the sex genotype of a primordial germ cell can be physiologically reversed by the hormonal characteristics of the gonad, there seemed no obstacle to obtaining sex-reversal of the transferred gonocytes in Xenopus.
Analysis of SDF-1/CXCR4 signaling in primordial germ cell migration and survival or differentiation in Xenopus laevis
