Enabling Hamster Embryo Culture System: Development of Preimplantation Embryos

Development of preimplantation embryos, from fertilization to hatched-blastocyst stage, has been a challenging task, regardless of the mammalian species being studied. While the mouse model has been versatile for studying in vitro development of early embryos, other rodent species are important to gain insights into comparative early embryogenesis. The golden hamster (Mesocricetus auratus) offers unique advantages to study cellular and molecular regulation of gamete maturation, fertilization and preimplantation development, including the phenomenon of blastocyst hatching. Achieving in vitro fertilization and first cleavage division is relatively easy; however, subsequent development past the two-/four-cell stage had been difficult in hamsters. Pioneering research, carried out over three decades has markedly enabled successful in vitro development of one-cell embryos to blastocysts. This article provides a comprehensive perspective (historical and current) on the embryo culture systems and details an optimized culture protocols to achieve normal and viable development of preimplantation embryos in the golden hamster.