Primary Culture of Mesodermal and Endodermal Cells of the Starfish Embryo

Abstract

A method is described for culturing embryonic cells of the starfish Asterias amurensis. A network composed purely of mesenchyme cells can be obtained by treating dissociated cells of embryos at the mesenchyme migration stage with 0.6 M glycine in half strength Ca2 , Mg2 free Jamarin (artificial sea water) for 24 hr and subsequently culturing them for 24 hr. When the treatment period is shortened to 12 hr, aggregates of epithelial cells come to coexist with the network. After 3 days of culture, these aggregates form monolayer sheets constituted of four types of cells which can be identified morphologically and by 8-anilino-1-naphthalenesulfonic acid (1, 8-ANS) stainability. These cell types correspond to cells composing the esophagus, the stomach, the intestine and the coelomic pouch. No ectodermal cells were found in the sheet. These results suggest that there is an order of resistibility to 0.6 M glycine treatment among cells of the three germ layers, i. e. mesoderm, endoderm and ectoderm in descending order.