[The effect of the micromanipulations used for transgenosis on mouse development]

Non-specific effects of micromanipulation techniques used for producing transgenic mice on processes of embryonic development were studied. Zygotes obtained from C57BL and BALBxDD mice were treated as follows: (1) incubated in culture medium; (2) the male pronucleus punctured with a glass microneedle; (3) microinjected with a buffer solution; and (4) DNA (mouse P-35 oncogene with human insulin gene promoter) injected into the male pronucleus. Then zygotes were transferred into oviducts of syngeneic or allogeneic pseudopregnant females. Such treatment resulted in the intrauterine death of embryos, as well as in birth of the dead or non-viable offspring with numerous defects of development. Zygote pronucleus puncturing is the most damaging manipulation, since its effect exceeds that of the zygote incubation and is comparable with the effect of buffer of DNA injections.