Study On The Detection, Identificiation And Methods For Maintenance Of Two Genetically Engineered Mice

According to the characteristics of the Neor Transgenic mouse and Five-Feature Translocus Mice Carrying Human IgM in Shanghai Transgenic Research Center, study was made respectively. The present research includes two parts, and the results are showed as follows: 1.The Founding and Screening of the Homozygous Neor Transgenic Mice StrainTen Minimal disease Ft mice were generated by the way of embryo transplanting. We apply the PCR and Southern blot method to detecting the integration of the The Neor gene during the breeding course of the transgenic mice , five FI positive offsprings who carrying the Neor gene were identified. Four homozygotes were screened by the PCR , Southern blot and mating analysis, then founded the lineage. The MEF made of heterozygous Neor Transgenic mouse embryos were proved be able to resist the G418 and serve as the feeder of ES cell.2.The study on the boilogy characterists of five-feature mouse carrying Human IgM The five-feature mice from the institue of Babraham were researched in the fertility, growth and immunization. Female typically become pregnant at 6-8 weeks of age. The average litter size, weaning number, the male rate is 5.6, 5.0, 56.0% respectively, which has signifantly different between litters; The average litter size, weaning number increase in the 1-4 birth with the parity increase, the fertility of the female begins to decline after it produced the fourth litter. The average interval between the births is 29.1 days and have not signifantly different. Growth: 29 female and 34 male mice were weighted from birth to the age of nine weeks at the same time of every week,when the age is larger than 4 weeks, the male grow quicker than the same age female and have significant difference. Immuncitication: the serum of five-feature express Human IgM and mouse IgM by the analysis of quantification and qualiflcation.The level of human IgM higher than that of the mouse IgM. The level of the Human IgM in the serum of the five male mice of thesame litter improve with the week increase, the human IgM in the serum elevatedfollowing immunizing the VEGF, the level elevate with the number of immunizationincrease.3.Comparison of vitrification cryopreservation among different stages of mouseembryosThe cryopreservation of different embryo stages collected from ICR, C57BL/6 and F1 of DBA*C57BL/6 was carried out by using vitrification method. The morphology, in vitro development and birth rates of these embryos were compared after frozen-thawed. The results showed that more than 75% of the morphology from 2-cell embryos to morula stages from different strains was normal, the normal morphology rates of 8-cell embryos being the highest, while those of blastulas being the lowest. The in vitro development rates became higher as the embryos developed. The morphology of in vivo and in vitro fertilized frozen 2-cell embryos showed no difference, but in vivo fertilized frozen 2-cell embryos have significantly higher in vitro development than those in vivo fertilized frozen 2-cell embryos. Embryos that underwent 3 times frozen-thawing remained normal morphology. The pregnant rate and birth rate of frozen 2-cell embryos after embryo transfer were 64% and 40% respectively, but lower than those of fresh 2-cell embryo transfer.