Ultrastructure of Spermatozoa from Infertility Patients

Standard examination of human semen currently remains a main test for examination of male fertility disorders. Although parameters of sperm quality in fertile men are generally higher than in sterile ones, there is a substantial overlap between the two populations, indicating that other important factors affect fertility, but are not assessed in conventional assay. Currently, tests determining the functional properties of sperm have been intensively developed. This review considers an electron microscopic examination of sperm, which assesses the structure and function of the sperm nuclear, penetration and motor apparatus. The detection of sperm chromatin structure can help to understand the causes of early embryonic malformation. Genetically caused and functional disorders of the structure and function of spermatozoa are discussed. Indications for electron microscopic examination of spermatozoa in fertility disorders are given

The Centriolar Adjunct–Appearance and Disassembly in Spermiogenesis and the Potential Impact on Fertility

During spermiogenesis, the proximal centriole forms a special microtubular structure: the centriolar adjunct. This structure appears at the spermatid stage, which is characterized by a condensed chromatin nucleus. We showed that the centriolar adjunct disappears completely in mature porcine spermatozoa. In humans, the centriolar adjunct remnants are present in a fraction of mature spermatids. For the first time, the structure of the centriolar adjunct in the cell, and its consequent impact on fertility, were examined. Ultrastructural analysis using transmission electron microscopy was performed on near 2000 spermatozoa per person, in two patients with idiopathic male sterility (IMS) and five healthy fertile donors. We measured the average length of the “proximal centriole + centriolar adjunct„ complex in sections, where it had parallel orientation in the section plane, and found that it was significantly longer in the spermatozoa of IMS patients than in the spermatozoa of healthy donors. This difference was independent of chromatin condensation deficiency, which was also observed in the spermatozoa of IMS patients. We suggest that zygote arrest may be related to an incompletely disassembled centriolar adjunct in a mature spermatozoon. Therefore, centriolar adjunct length can be potentially used as a complementary criterion for the immaturity of spermatozoa in the diagnostics of IMS patients