Tissue Differentiation in Mouse Teratocarcinomas in Lung Colonies from Ascitic Embryoid Bodies: (mouse...

Tissue differentiation in ascitic teratocarcinoma embryoid bodies (EBs) was investigated in the lung colony system of syngeneic 129/Sv and allogeneic Balb/c mice previously reported by us. In this report, tissues are classified as neural, epithelial and mesodermal tissues. Although multiple differentiation in these three groups of tissues became evident about a month following an injection of EBs, colonies containing only one type of tissue but not mesodermal were commonly found. There were few colonies containing only mesodermal or both neural and mesodermal tissues. This suggests that mesodermal tissue differentiation takes place, as in normal embryogenesis, through the formation of a mesodermal layer, which has not been found in vivo.