DNA preparation method can influence outcome of transgenic animal experiments.

摘要

We have compared the influence of two transgene purification techniques on the efficiency of creating transgenic sheep and mice. 387 sheep zygotes and 2737 mouse zygotes were microinjected with one of four transgenes. Transgenes were isolated from plasmid sequences either by agarose gel electrophoresis followed by gel extraction or by a single step sodium chloride gradient fractionation technique. Four transgenic sheep and 61 transgenic mice were produced. Both sheep and mouse embryos responded similarly to transgene preparation methods. Overall, pregnancy rate was higher for recipients that received embryos injected with NaCl purified DNA (mean±SEM: 64±7% vs. 38±7%). Offspring per zygote transferred (NaCl, 22±3% vs. Gel, 12±3%) and transgenics born per zygote transferred (NaCl, 3.9±0.6% vs. Gel, 1.5±0.6%) were higher when the NaCl purified DNA was used. The proportion of offspring born that were identified as transgenic did not differ between transgene purification methods. Transgenes respondeddifferently to methods of preparation. One of the four genes yielded a significantly higher proportion of transgenics when the transgene was prepared by NaCl purification. These data suggest that on average the NaCl gradient purification technique results in a higher embryo survival rate to term for both sheep and mice, but the technique has no influence on rate of transgene integration.