STUDY OF NUCLEAR DECONDENSATION OF THE RAT SPERMATOZOA BY REDUCING AGENTS DURING EPIDIDYMAL TRANSIT

Chromatin packing, mostly due to disulfide bond formation, is one impo rtant step in epididymal sperm maturation. In this study the in vitro effect of a reducing agent such as thioglycolate (Tg) was tested. Thio glycolate was assayed on rat sperm obtained from caput, corpus and cau da epididymides. Changes were verified via light microscopy (and area measurements) and both transmission and scanning electron microscopy u sing standard techniques. Due to the low molecular weight of Tg, it do es not require detergent to enter sperm. The nuclear decondensation el icited by Tg and its effect on sperm surface, differ from caput to cau da, although the final nuclear area is not significantly different. Th e pattern of sperm nuclear decondensation suggests that it starts at t he caudal segment of the head, perhaps due to the abundance of nuclear pores in this region. Under the experimental conditions described bel ow the perforatorium was not affected. Thus, the nature and role in th e rat sperm of the perforatorium deserves more detailed analysis.