Induction and differentiation of extra-embryonic mesoderm in the mouse

Extra-embryonic mesoderm, derived at the time of gastrulation from the primitive streak, gives rise to several tissues that function to provide the embryo with nutrients, a means of waste disposal, and mechanical protection. Little is known about the diffe.entiation of this tissue and about the growth and transcription factors involved. The present review focussed on growth and transcription factors that may be involved in differentiation of extra-embryonic mesoderm, and results from fate-mapping and transplantation studies. Methods in vitro available for assaying the effects of growth and transcription factors on development of extra-embryonic development are also discussed. Extra keywords: ES cells, yolk sac, amnion, chorioallantoic fusion, BMP-4, evx-I, cdx-4, brachyury, eed, FGF, Xwnt-8.