[Regional specificity within plasma membrane and nuclear membrane of goldfish sperm]

Combined SEM and TEM technique including thin sectioning, freeze-fracture and etching as well as cytochemical staining have been used for ultrastructural study on goldfish (Carassius auratus) sperm. It has been shown that primitive sperm plasma membrane and nuclear membrane are differentiated with regional specificity. The results from this study can be summarized as follows: 1. Intercalated protein particles are highly organized in the plasma membrane in the certain region of the head to form crystalline-like structure, in contrast rest of the area is rich in randomly or clustered particles. 2. Many vesicles in different size are often tightly packed in the head, neck and tail regions. Only these plasma membrane covering the vesicles contain almost no protein particles. 3. The vesicles can be densely stained cytochemically, suggesting the existence of glycoprotein. 4. Most of the nuclear membrane have no nuclear pores on it except the area near the neck part where many nuclear pores concentrate.