Development of early mouse and rabbit embryos without zona pellucida

Area of Science:

• Reproductive biology
• Developmental biology
• In vitro fertilization (IVF)

Background:

• Assessing embryo viability is crucial for successful assisted reproductive technologies.
• The zona pellucida's role in embryo development and cryosurvival is well-documented.
• Understanding species-specific differences in embryo development is essential for optimizing IVF protocols.

Purpose of the Study:

• To establish criteria for assessing the in vitro vitality of denuded rabbit and mouse embryos.
• To compare the developmental capacity of denuded mouse and rabbit embryos in vitro.
• To evaluate the impact of zona pellucida removal on rabbit embryo implantation.

Main Methods:

• Denuded rabbit and mouse embryos were cultured in vitro for 24 and 48 hours.
• Embryo vitality was assessed based on volume, cell number, and metaphase plate count.
• Implantation success was evaluated in synchronized recipient female rabbits.

Main Results:

• Mouse embryos demonstrated normal growth and development with or without the zona pellucida.
• Denuded rabbit embryos exhibited significantly reduced growth, evidenced by lower volume and cell number.
• Denuded rabbit embryos failed to implant in synchronized recipients, indicating a critical loss of developmental potential.

Conclusions:

• Zona pellucida removal severely compromises the developmental potential and implantation capacity of rabbit embryos.
• In vitro culture criteria for embryo vitality need to account for species-specific responses to zona pellucida removal.
• These findings highlight the importance of the zona pellucida for early rabbit embryo development and successful pregnancy.