IMMUNOCYTOCHEMICAL DETECTION OF THYMOCYTE ANTIGENIC DETERMINANTS IN DEVELOPING LYMPHOID ORGANS OF SEA BASS DICENTRARCHUS-LABRAX (L)

The monoclonal antibody DLT15 specifically recognised antigenic determ inants expressed during development of thymic lymphoid cells of the se a bass Dicentrarchus labrax (L.). They were first detected at day 30 p ost-hatching in the thymus of fish maintained at 16 degrees C; thereaf ter, a marked increase in the number of immunoreactive cells occurred mostly in the outer region of the thymus. The appearance of DLT15-immu noreactive cells in the 1S?nphoid organs was in the sequence thymus, h ead-kidney and spleen. The thymus thus appears to be a primary lymphoi d organ in the sea bass. Infrequent cells sharing the antigenic determ inants expressed on thymocytes were localised in the developing head-k idney and spleen. (C) 1996 Academic Press Limited