检测Cre位点特异重组酶活性的双报告转基因小鼠建立

目的建立用于检测Cre位点特异重组酶活性的双报告转基因小鼠.方法采用显微注射方法,将携带lacZ和人碱性磷酸酶(human alkaline phosphatase,hAP)报告基因的ZAP载体导入近交C57BL/6小鼠554枚受精卵;利用PCR,Southern blotting技术对其仔鼠进行基因整合鉴定;应用X-gal染色方法,对转基因小鼠胚胎进行转基因表达检测.结果存活的398枚受精卵被移入21只假孕受体小鼠输卵管;13只受体怀孕产下68只后代.合子存活率和出生率分别为71%(398/554)和17%(68/398).在68只小鼠中,5只雄性和4只雌性小鼠整合有双报告基因.转基因整合率和有效率分别为13%(9/68)和1.6%(9/554).9只首建鼠与正常C57 BL/6小鼠杂交产生F1代小鼠.F1代小鼠转基因的传递符合孟德尔规律,X-gal染色仅在3只首建鼠的13.5 d龄胚胎中观察到.结论检测Cre位点特异重组酶活性的双报告转基因小鼠已建立.

Establishment of double reporter transgenic mice for monitoring Cre recombinase activity

Objective To establish a double reporter transgenic mice for monitoring Cre recombinase activity. Methods ZAP DNA fragment with lacZ and human alkaline phosphatase (hAP) gene was microinjected into the male pronucleus of 554 fertilized eggs from C57BL/6 mice. The founder mice and their progeny were screened for integration of transgene into the mouse genome by PCR and Southern blotting. The expression of lacZ transgene at early embryos from F1 generation mice was analyzed by X gal staining. Results A total of 398 survival ZAP DNA injected fertilized eggs were transfered to the oviducts of 21 pseudopregnant recipient mice. Of the 21 recipient mice, 13 became pregnancy and gave birth to 68 offspring mice. The zygote survival rate and birth rate were 71% (398/554) and 17% (68/398), respectively. Of the 68 offspring mice, 9 mice (5 males and 4 females) were identified by PCR and Southern blot analysis. Total integration rate and efficiency of transgene was 13% (9/68) and 1.6% (9/554), respectively. Nine mice as the founders were back crossed to set up F1 generation with other inbred C57BL/6 mice. Out of 9 transgenic mice, transmission of reporter gene in F1 offspring mice followed Mendelian rules, but the expression of lacZ protein was detected at the early embryonic stage (13.5 days postcoitum) in only 3 mice. Conclusion A double reporter transgenic mice for monitoring Cre recombinase activity is established.