Convoluted cords, a new nuclear body in spermatocytes and spermatids of the rabbit

The convoluted cords present in the nuclei of rabbit primary spermatocytes and spermatids differ from previously described nuclear bodies. They are composed of proteic strands decorated with granules and, in most cases, are embedded in clusters of interchromatin granules. They are partly sensitive to trypsin and can be visualised with protein-specific stains. The decorating granules are similar in size and aspect to interchromatin granules. However, only the latter are continuously immunolabelled with anti-snRNPs (small ribonucleoproteins) antibodies during spermatogenesis. The complexity and organisation of the convoluted cords are modified specifically during cell differentiation. They might be involved in the storage, transport and release of interchromatin granules in male germ cells.