We studied the effects of different types of microinjections, such as the mechanical damage to cytoplasmic and nuclear membranes of the zygote and the injection of various gene-engineering constructs or buffer solutions into the cytoplasm or the pronucleus, on the preimplantation of murine embryos (CBA x x C57BL)F1. The survival rate of the embryos was estimated by their capacity to develop in vitro to the blastocyst or hatched blastocyst stages. Puncture of the cytoplasm using a microneedle and injection of buff or foreign DNA did not affect the zygotes capacity for further in vitro development. But, the puncture of the pronucleus and microinjection of gene-engineering constructs or buffer into it reliably decreased the survival rate of embryos, as compared to the control. The differences were found in the capacity of murine zygotes for in vitro development after injection with gene-engineering constructs.