Cryopreserved mouse embryos can successfully survive biopsy and refreezing

Area of Science:

• Reproductive biology and cryopreservation science.

Background:

• Cryopreservation of early-stage embryos is crucial for assisted reproductive technologies.
• Assessing the viability of embryos after multiple freeze-thaw cycles and biopsy is essential for improving success rates.

Purpose of the Study:

• To evaluate the developmental potential of cryopreserved mouse eight-cell embryos subjected to thawing, biopsy, refreezing, and subsequent in vitro and in vivo culture.
• To determine if a multi-step cryopreservation and biopsy process impacts embryo viability and development.

Main Methods:

• Mouse eight-cell embryos were cryopreserved, thawed, biopsied, refrozen, and thawed again.
• In vitro assessment involved comparing blastulation rates of treated embryos with controls (sham-operated and untreated).
• In vivo studies involved transferring treated and control embryos into pseudopregnant mice to assess implantation and fetal development rates.

Main Results:

• In vitro, biopsied embryos showed similar day 2 blastulation rates to control and sham-operated groups.
• In vivo, no significant differences were observed in implantation or day 18 fetal development rates between control and treated embryos.
• The multi-step process of thawing, biopsy, and refreezing did not adversely affect embryo progression to fetuses.

Conclusions:

• Cryopreserved mouse eight-cell embryos can withstand thawing, biopsy, and refreezing without compromising developmental potential.
• The findings support the feasibility of using cryopreservation in conjunction with preimplantation genetic diagnosis strategies.
• This research indicates potential for enhanced applications of embryo cryopreservation in reproductive medicine.