TY - JOUR

T1 - Effects of slow freezing and vitrification on embryo development in domestic cat

AU - Mokrousova, Valentina I.

AU - Okotrub, Konstantin A.

AU - Brusentsev, Eugeny Y.

AU - Kizilova, Elena A.

AU - Surovtsev, Nikolai V.

AU - Amstislavsky, Sergei Y.

N1 - © 2020 Blackwell Verlag GmbH.

PY - 2020/10/1

Y1 - 2020/10/1

N2 - Cryopreservation of gametes and embryos is used to maintain genetic diversity of domestic and wild felids. However, felid oocytes and preimplantation embryos contain large amount of intracellular lipids, which affect their cryosensitivity. The objective was to compare the effects of slow freezing and vitrification and to study lipid phase transition (LPT) during cooling in cat embryos. In vitro-derived embryos were cultured 48 hr up to 4–8 cell stage, thereafter were either slow frozen or vitrified. Propylene glycol (PG) alone was used as a cryoprotective agent (CPA) for slow freezing, and a mixture of PG and dimethyl sulfoxide (DMSO) were used as CPAs for vitrification. After thawing/warming, embryos were in vitro cultured additionally for 72 hr. The total time of in vitro culture was 120 hr for all the groups including non-frozen controls. Effects of both cryopreservation procedures on the subsequent embryo development and nuclear fragmentation rate in embryonic cells were compared. There was no significant differences among the percentages of embryos achieved morula and early blastocyst stage in frozen-thawed group (36.4% and 20.0%), in vitrified-warmed group (34.3% and 28.6%) and in controls (55.6% and 25.9%). Cell numbers as well as nuclear fragmentation rate did not differ in these three groups. Average lipid phase transition (LPT) temperature (T*) was found to be relatively low (–2.2 ± 1.3°C) for the domestic cat embryos. It is supposed that the low LPT of LDs may provide a good background for successful application of slow freezing to domestic cat embryos. Generally, our study indicates that slow freezing and vitrification are both applicable for domestic cat embryo cryopreservation.

AB - Cryopreservation of gametes and embryos is used to maintain genetic diversity of domestic and wild felids. However, felid oocytes and preimplantation embryos contain large amount of intracellular lipids, which affect their cryosensitivity. The objective was to compare the effects of slow freezing and vitrification and to study lipid phase transition (LPT) during cooling in cat embryos. In vitro-derived embryos were cultured 48 hr up to 4–8 cell stage, thereafter were either slow frozen or vitrified. Propylene glycol (PG) alone was used as a cryoprotective agent (CPA) for slow freezing, and a mixture of PG and dimethyl sulfoxide (DMSO) were used as CPAs for vitrification. After thawing/warming, embryos were in vitro cultured additionally for 72 hr. The total time of in vitro culture was 120 hr for all the groups including non-frozen controls. Effects of both cryopreservation procedures on the subsequent embryo development and nuclear fragmentation rate in embryonic cells were compared. There was no significant differences among the percentages of embryos achieved morula and early blastocyst stage in frozen-thawed group (36.4% and 20.0%), in vitrified-warmed group (34.3% and 28.6%) and in controls (55.6% and 25.9%). Cell numbers as well as nuclear fragmentation rate did not differ in these three groups. Average lipid phase transition (LPT) temperature (T*) was found to be relatively low (–2.2 ± 1.3°C) for the domestic cat embryos. It is supposed that the low LPT of LDs may provide a good background for successful application of slow freezing to domestic cat embryos. Generally, our study indicates that slow freezing and vitrification are both applicable for domestic cat embryo cryopreservation.

KW - domestic cat

KW - lipid phase transition

KW - preimplantation embryos

KW - Raman spectroscopy

KW - slow freezing

KW - vitrification

KW - SURVIVAL

KW - VIVO

KW - CRYOPRESERVATION

KW - IN-VITRO CULTURE

KW - TECHNOLOGIES

KW - INTEGRITY

KW - PHASE-TRANSITION

KW - PREIMPLANTATION EMBRYOS

KW - OOCYTES

KW - LIPIDS

UR - http://www.scopus.com/inward/record.url?scp=85089258262&partnerID=8YFLogxK

U2 - 10.1111/rda.13776

DO - 10.1111/rda.13776

M3 - Article

C2 - 33617098

AN - SCOPUS:85089258262

VL - 55

SP - 1328

EP - 1336

JO - Reproduction in Domestic Animals

JF - Reproduction in Domestic Animals

SN - 0936-6768

IS - 10

ER -