Abstract: Objective To study the techniques of in vitro fertilization (IVF) and embryo transfer applied for breeding APP/PS1 double transgenic mice. Methods The fertilization rates and birth rates were analyzed in both natural mating group and IVF group for breeding APP/PS1 double transgenic mice. The female C57BL/6 mice were given intraperitoneal injection of appropriate dose of PMSG-hCG. The super ovulation oocytes were collected for IVF with sperms which were taken from 12 weeks, 24 weeks, 36 weeks, 52 weeks and 72 weeks old APP/PS1 double transgenic male mice respectively. The 2-cells embryos were than transfer to the fallopian of pseudopregnant mice. The genotypes of newborn mice were identified by PCR. Results The fertilization rates were 73.3% in group of natural mating, but 95% in group of IVF. The statistic differentiation was significant in newborn mice number (P<0.05) between natural crossing group to IVF group, but was not marked in genotype positive rate (P>0.05). The fertilization rates, birth rates and genotype positive rate were evaluated in 12 weeks, 24 weeks, and 36 weeks old APP/PS1 double transgenic male mice by statistic analysis which showed that there were no significant difference among them (P>0.05 ). The IVF rates were 85.6%, 84.1% in 52 weeks, and 72 weeks old APP/PS1 double transgenic male mice those were so aging enough that could not breed the filial generation by usual method. Conclusion The application the techniques of IVF-ET can enlarge rapidly the breeding population of APP/PS1 double transgenic mice.

Key words: Mouse, IVF-ET, Alzheimer's disease, Expanded breeding