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Main Title Thermostability of Sperm Nuclei Assessed by Microinjection into Hamster Oocytes.
Author Yanagida, K. ; Perreault, S. D. ; Kleinfeld, R. G. ; Yanagimachi, R. ;
CORP Author Environmental Protection Agency, Research Triangle Park, NC. Reproductive Toxicology Branch. ;John A. Burns School of Medicine, Honolulu, HI. Dept. of Anatomy and Reproductive Biology.
Publisher c1991
Year Published 1991
Report Number EPA/600/J-91/053;
Stock Number PB91-191601
Additional Subjects Heat ; Spermatozoa ; Cell nucleus ; Microinjections ; Ovum ; Golden hamsters ; Autoradiography ; pH ; Species specificity ; Chickens ; Mice ; Cross-linking reagents ; Reprints ;
Library Call Number Additional Info Location Last
NTIS  PB91-191601 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
Nuclei isolated from spermatozoa of various species (golden hamster, mouse, human, rooster, and the fissh tilapia) were heated at 50 - 125 deg for 20-120 min and then microinjected into hamster oocytes to determine whether they could decondense and develop into pronuclei. Mature, mammalian sperm nuclei, which are stabilized by protamine disulfide bonds, were moderately heat resistance. For example, they remained capable of pronucleus formation even after pretreatment for 30 min at 90 C. Indeed, a temperature of 125 C (steam) was required to inactivate hamster sperm nuclei completely. On the other hand, nuclei of rooster and tilapia spermatozoa and those of immature hamster and mouse spermatozoa, which are not stabilized by protamine disulfide bonds, were sensitive to heating; although some of them decondensed after exposure to 90 C, none formed male pronuclei. Furthermore, nuclei of mature hamster sperm became heat labile when they were pretreated with dithiothreitol to reduce their protamine disulfide bonds. These observations suggest that the thermostability shown by the nuclei of mature spermatozoa of eutherian mammals is related to disulfide cross-linking of sperm protamines.