INVOLVEMENT OF THE PROTEIN OF XENOPUS-VASA HOMOLOG (XENOPUS-VASA-LIKEGENE-1, XVLG1) IN THE DIFFERENTIATION OF PRIMORDIAL GERM-CELLS

In order to understand the role of the protein of Xenopus vasa homolog (Xenopus vasa-like gene 1, XVLG1) in germ line cells, an attempt was made to perturb the function of the protein with the anti-vasa antibod y 2L-13. The 2L-13 or the control antibody was microinjected with a li neage tracer (FITC-dextran-lysine, FDL) into single vegetal blastomere s containing the germ plasm of Xenopus 32-cell embryos, the descendant s of which were destined to differentiate into a small number of primo rdial germ cells (PGC) and a large number of somatic cells, mostly of endodermal tissues at the tadpole stage. No significant effect of the injection of the antibodies on FDL-labeled, presumptive PGC (pPGC) was observed in embryos until stage 37/38. However, FDL-labeled PGC were not observed in almost all the 2L-13 antibody-injected tadpoles, altho ugh a similar number of labeled somatic cells were always present. As 2L-13 antibody specifically reacts with XVLG1 protein in the embryos b y immunoblotting, the present results suggest that the antibody pertur bed the function of XVLG1 protein in the pPGC, resulting in failure of PGC differentiation at the tadpole stage.