Mesodermalization of amphibian gastrula ectoderm in transfilter experiments.

Transfilter experiments were carried out with competent gastrula ectoderm of Triturus vulgaris and Ambystoma mexicanum as the reacting materials and blastoporal lip, alcohol-treated bone marrow and archenteron roof as the inducing materials, It was shown that a mesodermal inducing substance is able to penetrate Nuclepore filters of different pore sizes (3.0, 1.0, 0.4, 0.2 micrometer). The degree of mesodermal differentiations depends on the reacting materials, the inductors and the filters which were used in the transfilter experiments.