角质细胞特异性表达Cre重组酶转基因小鼠的建立

构建了含有角质细胞特异性角质素5启动子、Cre重组酶基因和人生长激素基因plyA的转基因载体pK5-Cre-hGH。以显微注射的方法将4．2kb的转基因片段K5-Cre-hGH引入小鼠基因组，共注射720枚受精卵，其中龄5枚移植至29只假孕母鼠的输卵管中发育，获得子代小鼠48只，经基因型鉴定有12只小鼠在其基因组上整合有Cre基因，整合率为25％。将带有cre重组酶基因的小鼠与基因组上携带loxP位点的smad4条件基因打靶小鼠杂交以检测Cre重组酶组织特异性表达情况以及介导重组的功能。结果表明，K5-Cre转基因小鼠只在皮肤组织中表达Cre重组酶并能在体内成功地介导loxP位点的重组。

Establishment of Keratinocyte-specific Cre Recombinase Transgenic Mice

A keratinocyte-specific Cre transgenic construct (pK5-Cre) containing the keratin 5 promoter,Cre recombinase gene and polyA of human growth hormone gene was generated.The 4.2 kb DNA fragment of K5-Cre-hGH was introduced into 720 fertilized zygotes by microinjection.695 injected eggs were implanted into the oviduct of 29 female mice respectively,from which 48 offspring were obtained.Twelve mice carrying the transgene were identified by genotyping,and the integration efficiency is 25%.The K5-Cre transgenic mice were crossed with Smad4 conditional gene targeting mice to check the tissue-specific expression of the Cre recombinase and the Cre mediated recombination in multiple tissues.The results showed that the Cre recombinase was expressed in skin tissue only and successfully mediated the recombination between the loxP sites in vivo.