Pronuclear formation and cleavage of mammalian eggs after microsurgical injection of freeze-dried sperm nuclei.
A study was conducted to evaluate the ability of mammalian oocytes to develop to the pronuclear stage and beyond if injected with freeze-dried sperm nuclei. The rate of development of hamster eggs to the pronuclear stage after microinjection of freeze-dried hamster sperm nuclei was 90%. The pronuclear formation rate of hamster eggs injected with freeze-dried human sperm nuclei was 85%. On the other hand, the rates for eggs injected with untreated sperm nuclei were 84% and 89% respectively. The survival rate of rabbit eggs microinjected with freeze-dried rabbit sperm nuclei was 64%, the fertilisation rate 56% and the cleavage rate 38%. The survival, fertilisation and cleavage rates of eggs injected with non-freeze-dried sperm nuclei were 78%, 45% and 34%, respectively. There was no difference between eggs injected with freeze-dried sperm nuclei and those injected with sperm nuclei that had not been freeze-dried. Of the viable rabbit eggs injected with freeze-dried rabbit sperm nuclei, 6% developed to the 6- to 8-cell stage 62 h after injection.
Hoshi
K
K
Fukushima Medical College, Japan.
Yanagida
K
K
Katayose
H
H
Yazawa
H
H
D000818:Animals; D002467:Cell Nucleus / Q000502:physiology*; D006224:Cricetinae; D005314:Embryonic and Fetal Development; D005307:Fertilization in Vitro / Q000379:methods*; D005612:Freeze Drying; D006801:Humans; D008297:Male; D008845:Microinjections; D011817:Rabbits; D051381:Rats; D013094:Spermatozoa / Q000502:physiology*; D015053:Zygote / Q000502:physiology*