Okamura Daiji, Kimura Thoru, Nakano Toru, Matsui Yasuhisa
Department of Molecular Embryology, Research Institute, Osaka Medical Center for Maternal and Child Health, 840, Murodo-cho, Izumi, Osaka, 594-1101, Japan.
Development. 2003 Dec;130(26):6423-30. doi: 10.1242/dev.00870. Epub 2003 Nov 19.
The germ cell lineage segregates from the somatic cell lineages in early embryos. Germ cell determination in mice is not regulated by maternally inherited germplasm, but is initiated within the embryo during gastrulation. However, the mechanisms of germ cell specification in mice remain unknown. We located precursors to primordial germ cells (PGCs) within early embryos, and show here that cell-cell interaction among these precursors is required for germ cell specification. We found that the expression of a calcium-dependent cell adhesion molecule, E-cadherin, is restricted to the proximal region of extra-embryonic mesoderm that contains PGC precursors, and that blocking the functions of E-cadherin with an antibody inhibits PGC formation in vitro. These results showed that E-cadherin-mediated cell-cell interaction among cells containing PGC precursors is essential to directing such cells to the germ cell fate.
生殖细胞谱系在早期胚胎中与体细胞谱系分离。小鼠生殖细胞的决定不受母系遗传种质的调控，而是在原肠胚形成期间在胚胎内启动。然而，小鼠生殖细胞特化的机制仍然未知。我们在早期胚胎中定位了原始生殖细胞（PGC）的前体细胞，并在此表明这些前体细胞之间的细胞间相互作用是生殖细胞特化所必需的。我们发现一种钙依赖性细胞粘附分子E-钙粘蛋白的表达仅限于包含PGC前体细胞的胚外中胚层的近端区域，并且用抗体阻断E-钙粘蛋白的功能会在体外抑制PGC的形成。这些结果表明，E-钙粘蛋白介导的包含PGC前体细胞之间的细胞间相互作用对于引导这些细胞走向生殖细胞命运至关重要。
