Effect of Vero cell coculture on the development of frozen-thawed two-cell mouse embryos.
OBJECTIVE
Our purpose was to evaluate the beneficial effects of long-term coculture of Vero cells on the development of frozen-thawed two-cell mouse embryos.


METHODS
Two-cell mouse embryos were frozen slowly with 1,2-propandiol and sucrose as cryoprotectants and thawed rapidly, followed by stepwise dilution. Vero cells were cultured in drops of RPMI 1640 to establish monolayers. Frozen-thawed embryos were cultured alone (control) or cocultured with Vero cells. The rate of development in both groups was compared.


RESULTS
After 4 days of culture, significantly more embryos in coculture were developed to expanded blastocysts (61 vs 37% for controls; P < or = 0.0001). In addition, on the fifth day of cultivation, more embryos in coculture showed the potential of hatching from the zona pellucida (26 vs 7% in controls; P < or = 0.0001). The rate of degeneration in coculture was also much lower than in controls (6 and 15%, respectively).


CONCLUSIONS
Coculture of cryopreserved preimplantation-stage embryos with Vero cells seems to be a useful tool to eliminate the postthaw deleterious effect of freezing and also to obtain better-quality embryos appropriate for transfer.
Nematollahi
N
N
Department of Anatomy, Kerman University of Medical Sciences, Iran.
Valojerdi
M R
MR
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D016022:Case-Control Studies; D002522:Chlorocebus aethiops; D018920:Coculture Techniques / Q000379:methods*; D015925:Cryopreservation; D004622:Embryo, Mammalian / Q000166:cytology* / Q000502:physiology; D005260:Female; D051379:Mice; D011247:Pregnancy; D014709:Vero Cells / Q000166:cytology