Develop to term rat oocytes injected with heat-dried sperm heads.
This study investigated the development of rat oocytes in vitro and in vivo following intracytoplasmic injection of heads from spermatozoa heat-dried at 50°C for 8 h and stored at 4°C in different gas phases. Sperm membrane and chromosome are damaged by the process of heat-drying. Oocyte activation and cleavage of oocytes were worse in oocytes injected with spermatozoa heat-dried and stored for 1 week than unheated, fresh spermatozoa, but in heat-dried spermatozoa, there were no differences in these abilities of oocytes between the samples stored in nitrogen gas and in air. The oocytes injected with heat-dried spermatozoa stored for 1 week could develop to the morula and blastocyst stages without difference between the samples stored in nitrogen gas and in air after artificial stimulation. Cleavage of oocytes and development of cleaved embryos were higher when heat-dried spermatozoa were stored for 3 and 6 months in nitrogen gas than in air. However, the ability of injected oocytes to develop to the morula and blastocyst stages was not inhibited even when heat-dried spermatozoa stored in both atmosphere conditions for as long as 6 months were used. When 2-cell embryos derived from oocytes injected with heads from spermatozoa heat-dried and stored for 1 week and 1 month were transferred, each 1 of 4 recipients was conceived, and the conceived recipients delivered 1 live young each. These results demonstrate that rat oocytes can be fertilized with heat-dried spermatozoa and that the fertilized oocytes can develop to term.
The Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
Kyung-Bon
KB
Lee
Ki-Eun
KE
Park
In-Kiu
IK
Kwon
Swamy K
SK
Tripurani
Keun Jung
KJ
Kim
Ji Hye
JH
Lee
Koji
K
Niwa
Min Kyu
MK
Kim
D000388:Air; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D003890:Desiccation; D010064:Embryo Implantation; D005260:Female; D005612:Freeze Drying; D006358:Hot Temperature; D008297:Male; D009028:Morula / Q000166:cytology / Q000502:physiology*; D009584:Nitrogen; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012662:Semen Preservation; D013077:Sperm Head / Q000502:physiology*; D020554:Sperm Injections, Intracytoplasmic
D009584:Nitrogen