[Methods used for gene manipulation in mammal female germ cells and early embryos]

For sexual reproduction, oocytes are mammalian female germ cells that provide the majority of maternal genetic material for early stage embryo production and development. Early stage embryos begin the process of multicellular organism formation through cell differentiation. Studies on mammalian female germ cells (oocytes) not only reveal its unique physiological characteristics, but also help understand the mechanism involved in cell differentiation of other cell types. However, because it is difficult to culture in vitro, our understanding of the function of oocytes and early stage embryos remains very limited. Gene editing or manipulation is one of the most commonly used method, which is also useful in the field of gametes study. In this review, we summarized the principles, advantages and disadvantages of techniques, which include conditional knockout, RNA interference, Morpholino, Trim-Away and antibody-mediated inhibition of protein function, currently used for gene manipulation in oocytes and early stage embryos. We also discuss the issues the investigators need to consider. Finally, we highlight the future directions for gene manipulation or editing in female germ cells and early stage embryos.