Ultrastructural Changes Occurring During Spermiogenesis of the Vervet Monkey, Chlorocebus aethiops

摘要

Background: Chlorocebusaethiops commonly known as the vervet monkey has been constantly used as an important animal model for human-related studies. Materials and Methods: The process of spermiogenesis of the vervet monkey was investigated with electron microscopic techniques. Twenty-nine male vervet monkeys were used in this study. Results: Based on the ultrastructural changes, spermatids were divided into 12 steps. The acrosome develops from merging transport vesicles that arise from the Golgi andsubsequently partition into acrosomal cap. Initial spermatids have dense cytoplasm with scattered mitochondria, a well-developed Golgi body and nuclei with patches of heterochromatin. Most of the cytoplasmic structures and mitochondria have undergone profound transformations. Nuclei and cell elongate and chromatin begins to condense near the nuclear envelope. An acrosomal complex appears at the tip of the nucleus. Manchette is clearly observed in the developing spermatids. The acrosomal filament runs the entire length of the nucleus. As a final step of spermiogenesis, cytoplasm has been significantly reduced. Mitochondria surround the midpiece as the anlage of the annulus forms. Phagocytic vesicles are observed in association with the developing spermatids. Conclusion: The results indicate that the processes of spermiogenesis of the vervet monkey are found to be fundamentally similar to that of other mammalian species, non-human primates and in particular to that of human. The findings of this study could also assist in early detection of defective sperm development.