Developmental capacity of mouse oocytes cryopreserved before and after maturation in vitro.
The survival and developmental capacity of cumulus cell-enclosed oocytes frozen (1) at the germinal vesicle (GV) stage, after maturation in vitro with (2) and without (3) FSH, and (4) after gonadotrophin-stimulated ovulation were assessed. Survival, defined as the number of morphologically normal oocytes, after freeze-thaw at the GV stage (69%), was lower than for oocytes frozen after ovulation (84%), and after maturation in vitro with FSH (88%) and without FSH (81%). Treatment with DMSO without freezing had no effect on survival when compared with untreated controls except in immature GV-stage oocytes for which there was a slight reduction. After insemination in vitro, 9% of frozen-thawed GV-stage oocytes cleaved to two equal blastomeres, but none developed to blastocysts. Of oocytes matured in vitro before freezing, 17% cleaved to the 2-cell stage and 18% of these developed to blastocysts. When oocytes were matured in vitro in the presence of FSH, however, the percentage cleaving to the 2-cell stage after freeze-thaw was improved to 55%, and 77% of 2-cell stage embryos developed to blastocysts. When ovulated cumulus cell-enclosed oocytes were frozen, 88% cleaved and 67% of the cleaved embryos developed to blastocysts. When 158 two-cell embryos resulting from oocytes matured in vitro with FSH were transferred to the oviducts of pseudopregnant foster mothers, 41 genetically marked live young were produced (26%).(ABSTRACT TRUNCATED AT 250 WORDS)
Schroeder
A C
AC
Jackson Laboratory, Bar Harbor, Maine 04609.
Champlin
A K
AK
Mobraaten
L E
LE
Eppig
J J
JJ
D000818:Animals; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D009865:Oocytes / Q000254:growth & development*; D010060:Ovulation / Q000187:drug effects; D010063:Ovum / Q000166:cytology / Q000187:drug effects
D005640:Follicle Stimulating Hormone