Distribution of keratins, vimentin, and actin in the testis of two South American camelids: Vicuna (Vicugna vicugna) and Llama (Lama glama). An immunohistochemical study

The purpose of the present study was to investigate the pattern of distribu tion of cytokeratins, vimentin and muscular actin in the testis of vicuna ( Vicugna vicugna) and llama (Lama glama) two species of camelids native of t he Andean high plateau of South America. Testicular biopsies of four vicuna s and five llamas were used. Animals were healthy breeders. The tissues were processed by standard immunohistochemistry try with antipa ncytokeratin AE1/AE3, antikeratin 18 (K 18), CAM 5.2 (antikeratin 5, 18, an d 19), antivimentin, and smooth-muscle-specific antiactin antibodies to tra ck the cytoskeletal pattern of testicular cells. Using AE1/AE3 antibody the immunostaining was found in the epithelial Lining of tubuli recti and rete testis, The reaction was relatively stronger in the apical cytoplasm of ep ithelial cells. The testicular cells of the two species showed no reaction to K 18 and CAM 5.2 antibodies. Antivimentin antibody stained the basal cyt oplasm of the Sertoli cells, the Leydig cells, and the epithelial lining of tubuli recti and rete testis. In the last; two structures the immunostain was relatively more intense in the basal cytoplasm of epithelial cells. Ant iactin antibody stained the peritubular cells and the muscle cells of the l amina propria of tubuli recti and rete testis. The presence in these specie s of only some keratins found in man, its coexpression with vimentin in epi thelial lining of tubuli recti and rete testis and the peritubule organizat ion, so different from other ungulates may reflect a differential adaptatio n of the cytoskeleton to particular reproductive strategies. Anat Rec 254:3 30-335, 1999. (C) 1999 Wiley-Liss, Inc.