摘要
目的构建组织型纤溶酶原激活剂(t-PA)乳腺定位表达载体,使其在牛乳汁中高效表达,从而建立牛乳腺生物反应器。方法RT-TD-PCR法克隆目的基因,通过酶切、连接、分离、纯化等方法构建含t-PA-cDAN的乳腺定位表达载体;采用显微注射法和乳腺注射法将融合基因转入小鼠的受精卵和小鼠及牛的乳腺组织中。结果显微注射法和乳腺注射法转基因后,t-PA可在小鼠和牛的乳汁中表达。结论所构建的乳腺定位表达载体可有效地使t-PA基因在小鼠和牛乳汁中表达,t-PA基因的表达不受转基因方法的影响,但t-PA在牛乳汁中的表达量明显高于小鼠的表达量,提示不同动物的乳蛋白调控系统有一定的差异,可能受着不同的因素或调控系统的影响。
Objective To construct an expression vector for highly efficient expression of tissue-type plasminogen activator (t-PA) confined in the mammary gland of cow to develop a cow mammary gland bioreactor. Methods RT-Touch down-PCR was employed to amplify human tissue-type plasminogen activator (t-PA) cDNA, which was digested with the restriction enzymes and subsequently cloned into the vector pSP72 for constructing specific fusion gene only expressed in the mammary gland. The fusion gene was then transferred into the mouse zygote and the mammary gland tissue of mice and cows. Results t-PA was detected in the milks of mice and cows after the transgenic manipulation with microinjection and mammary gland injection of the fusion gene. Conclusions The vector we constructed can effectively induce t-PA expression in the mammary gland, which is not influenced by different transgenic methods. The expression level of t-PA, however, is significantly higher in the milk of cows than in the milk of mice, suggesting the species-specific difference in milk protein regulating system possibly is due to different factors and regulatory systems.
出处
《第一军医大学学报》
CSCD
北大核心
2004年第5期546-548,552,共4页
Journal of First Military Medical University
基金
广州市科委重点项目(2000-Z-024-01-2)~~
