Survival Of Rabbit Embryos Research Articles

Effect of the Composition of Vitrification Media on Survival of Rabbit Embryos

A total of 448 rabbit morula stage embryos were used to examine the effect of modified vitrification procedure and vitrification media containing 10% (1.36 M) glycerol, 20% (2.72 M) 1,2-propanediol, and 1 M sucrose. The best result, 89.5% embryos developed in vitro, was obtained after equilibration, vitrification, and dilution of embryos using media in which the salt concentration was maintained constant on a molar basis. Media prepared on a molal basis were more toxic and/or less efficient.

Potential of hypertonic medium treatment for embryo micromanipulation: I. Survival of rabbit embryos in vitro and in vivo following sucrose treatment

Rabbit zygotes and embryos were exposed to hypertonic sucrose in phosphate-buffered saline (SPBS). In experiment one, 144 zygotes shrank to 32-36% of their initial volume in 1.0 M SPBS within 30 min. Neither hypertonic treatment with 0.5 M or 1.0 M SPBS nor micropuncture of the zona pellucida after shrinkage affected embryo development into blastocysts in vitro (88%, 83%, and 82%, respectively), compared to that of the controls (93%, P greater than .05). In experiment two, 252 two- to four-cell- and 177 morula-stage embryos were exposed to isotonic PBS control or 0.5 M, 1.0 M, or 1.5 M SPBS for 30, 60, 90, 120, and 150 min before transfer to PBS (290 mOsm). Embryo development was significantly reduced (P less than .05) when embryos were exposed in 0.5 M and 1.0 M SPBS for more than 60 min or in 1.5 M SPBS for more than 30 min. In experiment 3, morulae exposed for 60 min to 0.5 M or 1.0 M SPBS shrank to 37-39% or 32-35% of their initial volume and then expanded to 87-94% or 81-90% of their initial volume, respectively, after being returned to isotonic PBS for 60 min, but embryos in 1.5 M SPBS had erratic osmotic behavior. In experiment four, 192 two- to four-cell embryos exposed to 0.5 M SPBS for 0, 30, and 60 min before transfer to oviducts of recipients resulted in the production of 39%, 42% and 31% young, respectively (P greater than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Survival of rabbit embryos after culture or culture/freezing

Five-hundred-and-ninety-five rabbit embryos at the 2- to 4-cell stage were cultured for 48 h to the morula stage. One-hundred-and-sixty-three embryos were transferred directly after culture while the rest (432) were frozen to −196°C. The development of these embryos was tested by transfer into synchronized pseudopregnant recipients or into pseudopregnant recipients 24 h before synchrony. The results were determined at day 17 of pregnancy. The transfer of cultured embryos into synchronized recipients gave a higher survival rate than transfer into asynchronized recipients (51 vs. 15%; P<0.05). The freezing of cultured embryos affected in vitro and in vivo development. Only 56% of the frozen-thawed morulae developed to the blastocyst stage compared with 89% in the control group ( P<0.005). The survival rate after synchronous transfer was only 14%. Our results indicate that rabbit embryos need asynchronous conditions when they are frozen and cultured. Embryo survival rate was enhanced by 38% ( P<0.07) when these cultured frozen-thawed embryos were transferred into pseudopregnant recipients in an earlier physiological stage (−24 h).

Survival of rabbit embryos after synchronous or asynchronous transfer

Rabbit embryos of 2 and 16–32 cells and at late morula and blastocyst stages were collected from superovulated does and transferred directly into pseudopregnant recipients ovulated at different times. The development of the transferred embryos was determined at day 17 of pregnancy. With our tubal transfer technique a high survival rate was obtained. In synchronized recipients 68, 62 and 63% of the 2 and 16–32-cell embryos and those at late morula stage, respectively, developed into fetuses. Blastocysts could develop after transfer into the oviducts of synchronized or asynchronized (− 24 h) recipients but the survival rates were low: 21 and 24%, respectively. When the recipients and donors were asynchronized, the number of implants and fetuses was reduced. This reduction was considerable when the ovulation time difference between recipients and donors exceeded 24 h. No embryos survived in recipients ovulated 72 h after the donor.