关键词: 小鼠, 胚胎移植, 单侧, 双侧, 胚胎存活率

Abstract: Objective　To investigate the best conditions for surgical embryo transfer in C57BL/6J mice by evaluating the effects of embryo number and transfer location (unilateral or bilateral) on success rates. Methods　C57BL/6J embryos were cultured overnight to the two-cell stage and then transferred into ICR female mice. Researchers examined pregnancy rates, average litter size, and embryo survival under different conditions, including left, right, or bilateral surgeries with 15, 20, or 25 embryos transplanted. Results　Transplantation type and embryo number significantly affected embryo survival rates. Bilateral and right-sided transplants had higher survival rates than left-sided ones (P<0.05). Transplanting 20 embryos to the right side or bilaterally increased the number of pups and survival rate (P<0.05). Transplanting 25 embryos bilaterally resulted in the highest average number of pups, but the survival rate was similar to 20 embryos transplanted bilaterally or to the right side.Conclusion　Right-sided oviductal transplantation of 20 embryos in C57BL/6J mice not only yields superior transplantation outcomes but also minimizes surgical incisions and post-operative pain, enhancing animal welfare during the procedure.

Key words: mice, embryo transfer, unilateral, bilateral, embryo survival