Embryo cryopreservation and in vitro culture of preimplantation embryos in Campbell's hamster (Phodopus campbelli)

Abstract

The aims of this study were to compare different protocols of Campbell's hamster (Phodopus campbelli) embryos freezing–thawing and to explore the possibilities of their in vitro culture. First, the embryos were flushed from the reproductive ducts 2 days post coitum at the two-cell stage and cultured in rat one-cell embryo culture medium (R1ECM) for 48 hours. Most (86.7%) of the two-cell embryos developed to blastocysts in R1ECM. Second, the embryos at the two- to eight-cell stages were flushed on the third day post coitum. The eight-cell embryos were frozen in 0.25 mL straws according to standard procedures of slow cooling. Ethylene glycol (EG) was used either as a single cryoprotectant or in a mixture with sucrose. The survival of frozen-thawed embryos was assessed by double staining with fluorescein diacetate and propidium iodide. The use of EG as a single cryoprotectant resulted in fewer alive embryos when compared with control (fresh embryos), but combined use of EG and sucrose improved the survival rate after thawing. Furthermore, granulocyte-macrophage colony-stimulating factor rat (2 ng/mL) improved the rate of the hamster frozen-thawed embryo development in vitro by increasing the final cell number and alleviating nuclear fragmentation. Our data show the first attempt in freezing and thawing Campbell's hamster embryos and report the possibility of successful in vitro culture for this species in R1ECM supplemented with granulocyte-macrophage colony-stimulating factor.