Turtle lymphocyte surface antigens in chelydra serpentina as characterized by rabbit anti-turtle thymocyte sera

Spleen and thymus suspensions from the turtle, Chelydra serpentina were examined by indirect immunofluorescence with a rabbit anti-turtle thymocyte serum (RATT). After the species-specific antibodies had been absorbed out, the antisera labeled all lymphocytes in the thymus and spleen. The specificity of RATT for thymocytes was greater than the specificity for splenic lymphocytes. The presence of two antigens, one thymus specific, TS, and another shared by both thymocytes and splenic lymphocytes, LS, is suggested. The TS antigen was absent from a minor subpopulation of turtle thymocytes and may represent a mature population of T-like cells in the thymus.