Antibodies with the cell-type specificity to the morula cells of the solitary ascidians styela rustica and boltenia echinata

The separation of the blood cells of Styela rustica (Styelidae, Stolidobran chiae) in discontinuous Percoll gradient showed 4 fractions. The 4th and bo ttom most fraction contained 90-100% of morula cells. The protein compositi on of the morula cell fraction revealed on SDS-PAGE showed two major protei ns with m.w. 47 and 26 kDa. These proteins were heavily positively charged. Polyclonal antiserums against these proteins were raised. Each antiserum r eacted with both proteins only in morula cells on the blot after SDS-PAGE a nd stained the proper protein without crossreaction on the blot after AU-PA GE. The only type of cells stained with antibodies in circulating blood, in the tunic and on the tunic wound surface In paraffin sections of another s pecies Boltenia echinata (Pyuridae, Stolidobranchiae) were morula cells. Th e morula-type specific antibodies obtained recognized major positively char ged proteins which were apparently structural substrates for the phenoloxid ase tanning.