The structure of nuclear elements during spermiogenesis in the leopard frog has been examined. Contorted fibers occur in nuclei in each stage, including the mature sperm. Interchromatin granules have not been detected. In early spermatid nuclei (Stage 1), and in diffuse regions of middle spermatid nuclei (Stage 2), fibers are loosely packed. In condensed regions of Stage 2 nuclei and of later stages (Stages 3, 4 and mature sperm), fibers are closely packed. Fibers of about the same diameter occur in nuclei of each stage. The fibers are about 200 Å in diameter, considerably thicker than those of about 100 Å which have been reported previously. Possible explanations for this increased thickness are discussed.
ASJC Scopus subject areas
- Molecular Biology