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"CONTACT REACTIONS" BETWEEN XENOGENEIC OR ALLOGENEIC COELOMIC CELLS OF SOLITARY ASCIDIANS

1980; Marine Biological Laboratory (MBL); Volume: 158; Issue: 3 Linguagem: Inglês

10.2307/1540857

1939-8697

Masako T. Fuke,

Marine Ecology and Invasive Species

Coelomic cells from solitary ascidians exhibit a nonphagocytic cellular reaction when they are mixed in vitro with such cells from different species or another individual of the same species. The reaction is triggered by direct contact between reactive cells and hence was denoted "contact reaction." The contact reaction is reciprocal and results in mutual cell deaths or a state of prolonged incapacitation of both cells involved. Coelomic cells of several morphological types are capable of carrying out the reaction. Similar reactions were also observed in vivo when foreign cells were deliberately introduced into intact animals. Individuals from a single variant type of Halocynthia roretzi (Drasche) are mutually reactive when their cells are brought into contact, but not in every combination of individuals. The patterns of positive and negative contact reactivity among such allogeneic individuals do not follow conventional rules of transplantation genetics established for the vertebrates. These reactions seem to represent a cellular counterpart of non-fusion reactions in the colonial ascidians. However, unlike the colonial ascidians, in which fertilization between gametes from two individual colonies correlates with positive alloreactivity between them, that of solitary H. roretzi apparently takes place between any two individuals regardless of their mutual alloreactivity. The in vitro contact reaction is complete within a few minutes. Since coelomic cells can be tapped without sacrificing the donor animals, the in vitro contact reaction promises to be an excellent model for further studies of primitive self-nonself recognition at the cellular level.