MLR-like reaction between axial organ cells from asterids

The uptake of [3H]thymidine by axial organ (AO) cells arising from two starfishes and mixed together, in a ratio of 50/50 was studied. Mixed leucocyte reaction (MLR) combinations gave a positive response at the fifth day of culture in about 20% of the tested combination (index: 1.8-6.7). No positive reaction was observed in an allogeneic system. More significant results seem to be obtained with the nonadherent nylon-wool subpopulation cells from the two species, rather than with the whole axial organ cells.