Effect of post-IVF developmental kinetics on in vitro survival of vitrified-warmed domestic cat blastocysts.
A limited number of reports is available on cryopreservation of in vitro fertilization (IVF)-derived cat blastocysts. In the present study, IVF-derived domestic cat embryos which reached the blastocyst stage either on day 6 or day 7 were cryopreserved by vitrification using Cryotop as a cryodevice. Fresh control and post-warm surviving blastocysts were examined by differential cell staining with Hoechst 33342 and propidium iodide to determine total cell number and inner cell mass (ICM) ratio, and the post-warm survival rate was determined by re-expansion of the blastocoel during 24 h of in vitro culture. In fresh control, the mean number of total cells of day 7 blastocysts (61.4 cells) tended to be smaller than that of day 6 blastocysts (81.9 cells, p = 0.096). The post-warm survival rates of day 6 and day 7 blastocysts were not statistically different (73.8%; 31 of 42 vs 66.7%; 18 of 27). There were no significant differences in the total cell number and ICM ratio between fresh control and vitrified blastocysts, although the ICM ratio of surviving day 7 blastocysts was significantly smaller than that of fresh controls (stained at day 8, 18.9% vs 28.9%, p < 0.05). These results indicate that IVF-derived domestic cat embryos that reached the blastocyst stage earlier can survive the Cryotop vitrification without a reduction in the parameters studied.
Tsujioka
T
T
Graduate School of Science and Technology, Shinshu University, Nagano, JapanVeterinary College, Ludwig-Maximilians-University, Muenchen, GermanyFaculty of Textile Science and Technology, Shinshu University, Nagano, Japan.
Otzdorff
C
C
Graduate School of Science and Technology, Shinshu University, Nagano, JapanVeterinary College, Ludwig-Maximilians-University, Muenchen, GermanyFaculty of Textile Science and Technology, Shinshu University, Nagano, Japan.
Braun
J
J
Graduate School of Science and Technology, Shinshu University, Nagano, JapanVeterinary College, Ludwig-Maximilians-University, Muenchen, GermanyFaculty of Textile Science and Technology, Shinshu University, Nagano, Japan.
Hochi
S
S
Graduate School of Science and Technology, Shinshu University, Nagano, JapanVeterinary College, Ludwig-Maximilians-University, Muenchen, GermanyFaculty of Textile Science and Technology, Shinshu University, Nagano, Japan.
D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002415:Cats / Q000196:embryology*; D002452:Cell Count / Q000662:veterinary; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary*; D004622:Embryo, Mammalian / Q000502:physiology; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D007700:Kinetics