We assessed the viability of vitrified ovine blastocysts in vitro and in recipient ewes at different degrees of synchronization. Expanded ovine blastocysts obtained from superovulated Sarda ewes were exposed to a vitrification solution at 20 degrees C according to the following procedures: the blastocysts were added into 200 mu l glycerol (1.4 mol) for 5 min, then into 200 mu l glycerol (1.4 mol) and ethylene glyco (13.6 mol) for 5 min. These embryos were transferred into 25 mu l glycerol (3.4 mol) and ethylene glycol (4.6 mol) and loaded into the center of 0.25-ml straws separated from air bubbles by 2 columns of 90 mu l sucrose solution (0.5 mol). The straws were plunged immediately into liquid nitrogen (LN(2) ). The basic vitrification and thawing solution was phosphate buffered saline (PBS) supplemented with 20% fetal calf serum (FCS). The embryos were thawed by agitating the straws in a water bath at 20 degrees C, and expelling them into Petri dishes and mixing them, and placing the embryos into 200 mu l sucrose solution (0.25) mol for 5 min. The percentage of hatched blasticysts, after exposed and vitrified-thawed embryos, was 96.8% (30/31) and 82.8% (53/64), respectively, after 4 d of co-culture in TCM 199 medium with 10% FCS in 5% CO2 humidified atmosphere in air at 39 degrees C. Vitrified-thawed blastocysts, which re-formed the blastocoelic cavity after 24 h of co-culture as in the in vitro experiment, were surgically transferred into the uterine horn of recipients (2 embryos per ewe) at 6, 7 and 8 d after estrus. The pregnancy and lambing rates in recipient ewes at 6, 7 and 8 d after estrus were 72.7%, 90%, 54.5% and 72.7%, 80%, 45.4%, respectively. Both pregnancy and lambing rates differed significantly (P < 0.05) between the Day 7 and Day 8 groups.
Scheda prodotto non validato
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo
|Titolo:||Recipient synchronization affects viability of vitrified ovine blastocysts|
|Data di pubblicazione:||1995|
|Appare nelle tipologie:||1.1 Articolo in rivista|