Stage-dependent viability of vitrified rabbit embryos.

Area of Science:

• Reproductive Biology
• Cryobiology
• Developmental Biology

Background:

• Vitrification is a promising cryopreservation technique for embryos.
• Understanding the susceptibility of different developmental stages to vitrification is crucial for optimizing protocols.

Purpose of the Study:

• To assess the survival rates of rabbit embryos at various developmental stages following vitrification.
• To evaluate the efficacy of two different vitrification solutions in preserving rabbit embryos.
• To determine the viability of vitrified rabbit embryos by assessing live offspring rates.

Main Methods:

• Vitrification of 676 rabbit embryos at 1-cell, 2-cell, 8-to-16-cell, morula, and blastocyst stages.
• Use of two vitrification solutions: Solution I (30% 1,2-propanediol + 30% glycerol) and Solution II (35% 1,2-propanediol + 35% glycerol).
• Cryopreservation involved nitrogen vapor exposure followed by plunging into liquid nitrogen, with rapid thawing in 1-M sucrose solution.

Main Results:

• Solution I yielded 0% survival for 1- and 2-cell embryos, but 23.0% for 8-to-16-cell, 82.7% for morula, and 78.5% for blastocysts.
• Solution II resulted in 20.0% survival for 1-cell, 43.8% for 2-cell, and 92.9% for 8-to-16-cell embryos.
• Post-transfer of vitrified morula, live offspring rate was 26.5%, comparable to the control group's 24.0%.

Conclusions:

• Rabbit embryos show varying susceptibility to vitrification based on developmental stage.
• Morula and blastocyst stages demonstrate higher tolerance and survival rates post-vitrification.
• The proposed vitrification methods are effective for cryopreserving rabbit embryos, with potential for successful development.