T‐Cell‐Specific Membrane Antigens in the MexicanAxolotl (Urodele Amphibian)

Comparative analysis of SDS‐PAGE patterns of axolotl spleen cells membrane detergent lysates showed important discrepancies between control and thymectomized animals. Among these, a 38‐kD protein band, which appeared as a major protein in controls, was not or poorly expressed after thymectomy. A rabbit antiserum (L12) raised against the 38‐kD eluted band labeled in indirect immunofluorescence 80‐86% of thymocytes and 40‐46% of mIg – lymphoid cells in the spleen. The anti‐38‐kD antibodies stained in Western blotting two antigenically related polypeptides of 38‐ and 36‐kD on splenocyte membrane lysates. Two‐dimensional NEPHGE‐PAGE analysis indicated that the anti‐38‐kD antibodies reacted in the spleen with several gathered spots in the 7.8–8.2 pI range, corresponding to 38–36‐kD microheterogeneous polypeptides. Most of these spots are not further expressed in thymectomized animals. These results support evidence that the 38‐kD surface antigens can be considered as specific surface markers of the axolotl thymus‐derived lymphocytes.