Comparison of the media for isolation and storage of round spermatid nuclei before intracytoplasmic injection.
OBJECTIVE
This study investigated whether K(+)-rich medium is better than pure NaCl solution or Na(+)-rich cell culture medium for handling round spermatid nuclei prior to injection into oocytes (ROSNI).


METHODS
Round spermatids of the mouse were isolated and stored in isotonic NaCl, a cell culture medium (CZB), or a nucleus isolation medium (NIM) before injection into oocytes. The rates of normal fertilization, embryonic development in vitro, and birth of normal offspring after transfer of embryos to foster mothers were determined.


RESULTS
In vitro development of ROSNI-produced zygotes to blastocysts was the same when "naked" spermatid nuclei were exposed briefly to three media. However, a long (60-min) exposure of the nuclei to Na(+)-rich medium was detrimental. In K(+)-rich NIM "naked" spermatid nuclei best retained their ability to participate in normal embryonic development.


CONCLUSIONS
NIM was better than Na(+)-rich medium for retaining isolated spermatids competent to participate in normal embryonic development.
Suzuki
K
K
Department of Anatomy and Reproductive Biology, University of Hawaii School of Medicine, Honolulu 96822, USA.
Yanagida
K
K
Yanagimachi
R
R
D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000502:physiology; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D008297:Male; D051379:Mice; D008857:Microscopy, Interference; D008858:Microscopy, Phase-Contrast; D009865:Oocytes / Q000502:physiology; D011188:Potassium / Q000494:pharmacology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D012964:Sodium / Q000494:pharmacology*; D013084:Sperm-Ovum Interactions / Q000187:drug effects / Q000502:physiology*; D013087:Spermatids / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure
D003470:Culture Media; D012964:Sodium; D011188:Potassium