Presenilin-1/Presenilin-2双基因敲除小鼠的繁育及基因型鉴定

Breeding and Identifying Presenilin-1 and Presenilin-2 Conditional Double Knockout Mice

目的:繁殖及鉴定Presenilins双基因敲除小鼠,为进一步研究阿尔茨海默症(AD)奠定基础。方法:将引进的野生型及PS1/PS2双基因敲除小鼠进行饲养并繁殖,繁殖成功的子代小鼠基因型有野生型、杂合子和纯合子3种。提取子代小鼠鼠尾基因组DNA,用PCR法和琼脂糖凝胶电泳鉴定基因类型。结果:PS1/PS2双基因敲除小鼠的饲养和繁殖均获得成功,繁殖结果符合孟德尔遗传规律,同时获得更多基因型小鼠和Presenilins双基因敲除小鼠。结论:正确的饲养繁殖以及鉴定方法是获得PS1/PS2双基因敲除小鼠的有效途径。

Objective： To breed and identify presenilin-1 （PS1） and presenilin-2 （PS2） conditional double knockout mice （dKO）, in order to further study the molecular and neuronal mechanisms underlying the pathogenesis of Alzheimer＇s disease （AD）. Methods： Based on the genotypes of the initial breeders that were transported into China from our collaborator at USA, four mating pairs were set up. The plug was confirmed at about 3-5 days after breeding, and plugged female mice were carefully maintained in the animal facility at the College. After delivery, pups were weaned at postnatal day 20 （P20）, and a small fragment of tail was clipped from each pup. The genomic DNA was extracted, and PCR with three sets of primers that respectively recognize and distinguish the Cre transgene, PSI floxed/wild-type alleles, and PS2 knockout/wild-type alleles was performed. The amplified DNA fragments were separated by agarose gel electrophoresis, and visualized by UV. Results： PCR products from all three PCR amplifications showed the correct size for each allele as it was expected. Based on the distributions of genotypes among the pups, the penetration of each genotype was accordant with the Mendelian inheritance law. At this stage, we have obtained PS1/PS2 homozygous dKO mice. Conclusion： The introduced dko mice from USA have been successfully bred in our animal facility, and the colonies are under expanding currently.