Tolerance of the Mouse Sperm Nuclei to Freeze-Drying Depends on Their Disulfide Status

Tolerance of the Mouse Sperm Nuclei to Freeze-Drying Depends on Their Disulfide Status
July 29, 2003
Takehito Kaneko , David G. Whittingham , James W. Overstreet , and Ryuzo Yanagimachi
Biology of Reproduction
Abstract
Mouse spermatozoa from the caudae epididymides could be freeze-dried without losing their ability to support normal development. Immature spermatozoa from the testes, in contrast, were damaged by freeze-drying. However, immature spermatozoa became resistant to freeze-drying after their treatment with diamide, which oxidizes free -SH groups. Conversely, epididymal spermatozoa were damaged by freeze-drying if first treated with dithiothreitol (DTT), which reduces -SS- bonds. The potential for freeze-drying damage seems likely to relate to the -SS- status of sperm proteins, in particular its protamines.
Key words: Gamete Biology ? Testis ? Epididymis ? Fertilization ? Sperm