外源基因在转基因小鼠中遗传和表达的稳定性

Genetics and Expression Stability of Exogencus GeneConstruct in Transgcnic Mice

通过显微注射将外源基因构件１０６（酪蛋白基因调控区指导的乙肝病毒表面抗原基因表达构件）导入小鼠受精卵中，用ＰＣＲ-Ｓｏｕｔｈｅｍ方法进行外源基因的整合检测、ＥＬＩＳＡ法进行外源基因的表达检测，对４代转基因小鼠进行了跟踪测定。结果表明：原代转基因小鼠的整合率为５６％（１７／３０），原代雌鼠乳汁中转基因产物的表达率为１００％（８／８）；传代跟踪考察证明，外源基因在转基因小鼠中可以稳定遗传并在后代中表达目标产物；但后代中外源基因的整合率不符合“单一位点随机整合”的假说，家系分析推测外源基因在受精卵中的整合可能存在多位点整合机制；后代中外源基因的表达量有升高和降低的趋势，这可能与其位置效应、拷贝数和遗传信息物质跨越代界时ｉｍｐｒｉｎｔｉｎｇ图式的改变相关。

ransgenic mice were produced by introduced exogene construct 106, anexpression construct of HBsAg gene directed by bovine casein gene. withmicroinjection Gene integration test with PCR-Southem hybridization,shows that theconstruct integration rate is 56%(17/30), and expressed rate, by ELISA, of targetgene product HBsAg is 100% (8/8) in the first generation. Generation trailing testsuggests that the gene construct can be stably inherited across generation aftergeneration,and expressed more or less than Farents among offspring. However positiverate of offspring does not follow genetic ratio that exogenous gene can be integratedrandomly into a single site on chromosomes.There may be a machinery of multi-sitesfor exo-gene integration. Changes of the target gene expression in the offsprings maybe related to position effect changing of gene copy namber and changing ofchromatin imprinting pattern when parent`s genome infomation was delivered to theirProgeny.