Immunological evidence for the presence in sea urchin embryos of a cell adhesion protein similar to mouse uvomorulin (E-cadherin).

A tryptic fragment (88 kDa), obtained from external digestion of sea urchin embryos carried out in the presence of calcium, shows immunological cross-reactivity with polyclonal and monoclonal antibodies (DECMA-1) against mouse teratocarcinoma uvomorulin. Fab fragments obtained from anti-mouse terato-carcinoma uvomorulin mono- and polyclonal antibodies, and from polyclonal antibodies against the partially purified 88-kDa tryptic fragment, decompact early sea urchin embryos and block reaggregation of dissociated sea urchin blastula cells. These data indicate the presence of an uvomorulin-like protein in sea urchin embryos and suggest an important role for this protein in embryonic development.