Optimization and Application of Mouse Embryo Transfer Technology

doi:10.12300/j.issn.1674-5817.2026.069

Abstract

Abstract:

Objective To optimize the technical parameters of mouse embryo transfer(including oviduct opening method, pseudopregnant recipient body weight, number of embryos transferred per recipient, and unilateral vs. bilateral oviduct transfer), improve the efficiency of embryo transfer (the pregnancy rate of recipient female mice after embryo transfer was used as the evaluation index), and enhance the utilization rate of high-quality embryo germplasm resources(the birth rate of mice after embryo transfer was used as the evaluation index). Methods ICR mice and C57BL/6J mice were used as experimental materials. High-quality 2-cell embryos were obtained through in vitro fertilization. We adopted the single-factor controlled variable method to systematically investigate the effects of four factors, including oviduct opening method, pseudopregnant recipient body weight, number of embryos transferred per recipient, and unilateral vs. bilateral oviduct transfer, on the pregnancy rate and birth rate of mouse embryo transfer. Results The pregnancy rate of recipients with oviduct ostia punctured using a 26G syringe needle reached 90%, which was significantly higher than the 43% in the group with oviduct openings cut by Venus scissors (p<0.05). Pseudopregnant recipients weighing 28-35 g exhibited optimal embryo transfer outcomes, with a pregnancy rate of 90% and a birth rate of 44%, and no pups were crushed by foster mothers. The highest birth rate 42% was observed in the group receiving 16-25 embryos per recipient. Transferring 26-35 embryos per recipient achieved a 90% pregnancy rate and maximized embryo utilization efficiency. However, transfer efficiency decreased significantly when more than 35 embryos were transferred. Transfer of 24-26 embryos per recipient could balance relatively high pregnancy and birth rates. Bilateral oviduct transfer of mouse embryos yielded slightly higher pregnancy and birth rates than unilateral transfer, but the difference was not statistically significant (p>0.05). Conclusion Selecting pseudopregnant recipient female mice weighing 28-35 g, adopting the oviduct opening method with a 26G syringe needle for puncture, and controlling the number of transferred embryos at 24-26 per recipient can effectively improve the success rate of embryo transfer and achieve efficient utilization of high-quality embryo germplasm resources.

Key words: Mouse, Embryo transfer, In vitro fertilization, Technical optimization, Transfer efficiency

CLC Number:

Q95-33

ZHANG Jiaoling,LIN Aping,XU Shiying,et al. Optimization and Application of Mouse Embryo Transfer Technology[J]. Laboratory Animal and Comparative Medicine. DOI: 10.12300/j.issn.1674-5817.2026.069.

Figures/Tables 4

Note： A， Schematic diagram of oviduct ostium incision using Vannas micro-scissors. B， Schematic diagram of oviduct ostium puncture using a 26G syringe needle. C， Statistical results of pregnancy rate in recipient mice with two incision methods. D， Statistical results of pup birth rate after embryo transfer with two incision methods. ^***p < 0.001.
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Figure 1 Comparison of two oviduct incision methods （Vannas scissors cutting vs 26G needle puncture） on pregnancy rate and pup birth rate of pseudopregnant ICR mice during embryo transfer
Note： A， Schematic diagram of oviduct ostium incision using Vannas micro-scissors. B， Schematic diagram of oviduct ostium puncture using a 26G syringe needle. C， Statistical results of pregnancy rate in recipient mice with two incision methods. D， Statistical results of pup birth rate after embryo transfer with two incision methods. ^***p < 0.001.

Note： A， Comparison of pregnancy rate in recipient mice among different body weight groups； B， Comparison of pup birth rate among different body weight groups； C， Comparison of 7-day pup survival rate among different body weight groups. ^*p<0.05， ^**p<0.01， ^***p<0.001， ^****p<0.000 1.
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Figure 2 Effects of ICR pseudopregnant recipients with different body weight ranges on pregnancy rate， pup birth rate and 7-day-old pup survival rate following embryo transfer
Note： A， Comparison of pregnancy rate in recipient mice among different body weight groups； B， Comparison of pup birth rate among different body weight groups； C， Comparison of 7-day pup survival rate among different body weight groups. ^*p<0.05， ^**p<0.01， ^***p<0.001， ^****p<0.000 1.

Note： A and C， Pregnancy rates of recipients transplanted with embryos at gradient doses of 5-15， 16-25， 26-35 and 36-45 embryos； B and D， Corresponding pup birth rates in each group. C and D， Outcomes of refined gradient groups with 20-35 embryos. ^nsp>0.05， ^**p<0.01， ^***p<0.001， ^****p<0.000 1.
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Figure 3 Effects of transferring different numbers of 2-cell embryos in a single operation on pregnancy rate and pup birth rate of pseudopregnant ICR mice
Note： A and C， Pregnancy rates of recipients transplanted with embryos at gradient doses of 5-15， 16-25， 26-35 and 36-45 embryos； B and D， Corresponding pup birth rates in each group. C and D， Outcomes of refined gradient groups with 20-35 embryos. ^nsp>0.05， ^**p<0.01， ^***p<0.001， ^****p<0.000 1.

Note： A， Pregnancy rate of recipient mice subjected to unilateral or bilateral oviduct transfer； B， Pup birth rate after unilateral or bilateral oviduct transfer.^nsp>0.05.
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Figure 4 Comparison of pregnancy rate and pup birth rate between unilateral and bilateral oviduct embryo transfer in pseudopregnant ICR mice
Note： A， Pregnancy rate of recipient mice subjected to unilateral or bilateral oviduct transfer； B， Pup birth rate after unilateral or bilateral oviduct transfer.^nsp>0.05.

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