携带xylE的转基因小鼠的制备

Development of transgenic mouse model containing xylE target gene

建立了一种新的转基因小鼠致突变检测模型．选用ｘｙｌＥ基因作为诱变的靶基因，以ｐＥＳｎｘ穿梭质粒作为载体，通过显微注射法将线状ｐＥＳｎｘ导入ＩＣＲ小鼠制备Ｇ０小鼠．将显微注射后存活的３５２／５４９枚受精卵分别移入２４只受体雌鼠的输卵管中，共产生４１只仔鼠，存活３０只（Ｇ０），经过整合检测，检测出转基因小鼠１７只，阳性率为５７％．从中筛选出２只完整整合了ｐＥＳｎｘ的转基因小鼠作为首建鼠（ｆｏｕｎｄｅｒｍｏｕｓｅ）进行繁育，目前已繁殖到第三代（Ｇ３）．经过逐代整合检测，证明转入的基因可稳定地遗传．上述结果表明已成功地制备了在基因组中整合了ｐＥＳｎｘ质粒携带ｘｙｌＥ的转基因小鼠．

Transgenic mouse mutation test model provided a powerful tool for studying gene mutation in vivo. In this study, two transgenic mouse lines containing xylE gene as mutational target gene in a recoverable pESnx plasmid(12.7 kb) was constructed by microinjection. Five hundred and forty nine fertilized eggs of ICR mice were microinjected with pESnx DNA, 352 survival embryos were then transferred to oviducts of 24 pseudopregnant females respectively which produced 41 offspring. Eleven of them died in few days after birth. The 30 survival offsprings were screened for incorporation of the foreign DNA. Seventeen positive offsprings were identified. Finally, two (No. 9 and No. 31) stout male mice with intact pESnx DNA in their genomes were chosen as founder mice for establishing transgenic lineages respectively. So far G 1, G 2, G 3 offsprings were got. Through screening for incorporation of the foreign DNA, it indicated the integrated pESnx can stably transmit to subsequent generation.