Ultrastructure of spermatogonia, spermatocytes, and sertoli cells in the testis of the crayfish, Procambarus paeninsulanus

The testes of the crayfish, Procambarus paeninsulanus, were prepared for light and transmission electron microscopy. During early stages of spermatogenesis, when the spermatogonia are dividing, processes from a single Sertoli cell extend between numerous spermatogonia. As the cells enter meiosis, many points of contact can be observed between the Sertoli cell processes and spermatocytes. These desmosome-gap junctions are maintained between the germ and Sertoli cells until the early spermatid stage.