Transplantes singênico e xenogênico de espermatogônias troncos em gatos doméstico (Felis catus) adultos.

Abstract

Similar to most wild felids, the ocelot (Leopardus pardalis) is an endangered species. Aggravating this situation, knowledge on the reproductive biology of the ocelot is very limited. Germ cell transplantation is an effective technique for investigating spermatogenesis and stem cell biology in mammals. The domestic cat is a potential recipient model for preserving and propagating male germplasm from threatened or endangered wild felids. The morphological characterization of germ cells and knowledge on cycle length are potential tools for tracking the development of transplanted germ cells. Our goal was to investigate basic aspects related to testis structure, particularly spermatogenesis, in the ocelot. Four adult males were used. After unilateral orchiectomy, testis samples were routinely prepared for histological, stereological and autoradiographic analyses. Testis weight and the gonadosomatic index were 11±0.6g and 0.16±0.01%, respectively, whereas the volume density of seminiferous tubules and Leydig cells was 83±1.6 and 10±1.5%, respectively. Based on the acrosomic system, eight stages of spermatogenesis were characterized and germ cell morphology was very similar to that of domestic cats. Each spermatogenic cycle lasted 12.5±0.4 d and the entire spermatogenic process lasted 56.3±1.9 d. Individual Leydig cell volume was 2500 µm3, whereas the number of Leydig and Sertoli cells per testis gram was 38±5x106 and 46±3x106, respectively. Approximately 4.5 spermatids were found per Sertoli cell, whereas daily sperm production per testis gram was 18.3±1x106. The knowledge obtained in this study could be very useful to the preservation of the ocelot using domestic cat testes to generate and propagate the ocelot genome.Key words: testis; stereology; spermatogenic efficiency; spermatogenic cycle length; ocelot (Leopardus pardalis).