Scanning electron microscopy in the assessment of sperm morphology.

The advantages of using scanning electron microscope (SEM) vis-a-vis light microscope (LM) to assess sperm morphology was studied. The semen samples obtained from 15 fertile (group I) and 25 infertile (group II) men were processed by routine procedures for LM and SEM. The usually described sperm abnormalities were identifiable with greater resolution. Sperm abnormalities were significantly more in group II, as compared with group I (P less than 0.001) by both methods. Abnormalities of different regions, like thinning of midpiece, were scored higher in SEM than in LM. The abnormality of aggregation or retraction of mitochondrial sheath was clearly visible under SEM and missed by LM. Apart from detection of certain subtle abnormalities, SEM has advantages of rapid screening, accurate quantitation directly from the screen, zooming to higher magnification and automation.

Ultrastructural studies on the epididymal spermatozoa in the rhesus monkey.

Ultrastructural studies on the spermatozoa in different regions of the epididymis of the rhesus monkey have shown that the process of sperm maturation is associated with the caudad migration of the cytoplastmic droplet, a reduction in the volume of the cytoplasmic droplet, and an obvious wrinkling of the plasma membrane surrounding the head of the spermatozoa. These changes are completed by the time the spermatozoa reach the distal-middle segment of the epididymis. The present studies also indicate that spermatozoa are incorporated into the intraepithelial cells in the epidymis. This finding suggests that spermiophagy is a normal occurrence in the epidymis of rhesus monkey.