Qin Sheng-fang, Tan Wei-dong, Chen You-nan, Ding Yang, Li Sheng-fu, Li Hong-xia, Wang Li, Yang Rong, Lu Yan-rong
Department of Genesiology and Physiology, College of Public Health, Chongqing University of Medical Science, Chongqing 400016, China.
Sichuan Da Xue Xue Bao Yi Xue Ban. 2007 Jun;38(3):378-81.
To screen the target rhesus genes and give some basic genetic evidences to its value as one of the most important animal model in biomedical study, we constructed a cDNA expression library from liver tissue of a healthy rhesus monkey.
With Trizol reagent, the total RNA was extracted from healthy rhesus liver tissue. By mutant Moloney Murine Leukemia Virus Reverse Transcriptase (MMLV-RT), the first-strand cDNA was synthesized from purified mRNA, and subsequently the second-strand cDNA was generated via E. coli DNA polymerase I . Then, the EcoR I adapter was added to the synthesized double-strand cDNA, which was subsequently digested by Xho I restriction enzyme and fractionated with CHROMA APIN-400 column. The fractionated cDNA fragments to be longer than 0. 5 kb were ligated into lambda ZAP express vector to form the phagemid cDNA recombinants, which were further packaged into the lambda ZAP cDNA library according to the standard protocol with phage lambda Gold packaging extract. In order to get more stable clones with larger quantity, the primary library was amplified through infecting the host strain XL1-Blue MRF'. Then, the library titre, recombinant rate and length of inserted cDNA were measured, respectively.
The capacity of the primary stand or unamplified library was 1. 2X 10(6) pfu. The titers of the unamplified library or the amplified library was 1.1 X 10(6) mixture, pfu/mL or 7. 7 X 10(9) pfu/mL respectively, the percentages of recombinants were 99. 3% and 98. 2%, and the average lengths of the inserts were 2.0 kb and 2. 3 kb, respectively.
An excellent cDNA expression library has been constructed successfully, which would lay solid foundation for transplantation study and pre-clinic evaluation of related drugs.
为筛选恒河猴目标基因,并为其作为生物医学研究中最重要的动物模型之一的价值提供一些基础遗传学证据,我们构建了一个来自健康恒河猴肝脏组织的cDNA表达文库。
用Trizol试剂从健康恒河猴肝脏组织中提取总RNA。通过突变型莫洛尼鼠白血病病毒逆转录酶(MMLV-RT),从纯化的mRNA合成第一链cDNA,随后通过大肠杆菌DNA聚合酶I生成第二链cDNA。然后,将EcoR I接头添加到合成的双链cDNA中,随后用Xho I限制性内切酶消化并用CHROMA APIN-400柱分级分离。将长度大于0.5 kb的分级分离的cDNA片段连接到λZAP表达载体中以形成噬菌粒cDNA重组体,根据标准方案用噬菌体λGold包装提取物将其进一步包装到λZAP cDNA文库中。为了获得更多数量且更稳定的克隆,通过感染宿主菌株XL1-Blue MRF'对原始文库进行扩增。然后,分别测量文库滴度、重组率和插入cDNA的长度。
原始文库或未扩增文库的容量为1.2×10⁶ pfu。未扩增文库或扩增文库的滴度分别为1.1×10⁶混合物,pfu/mL或7.7×10⁹ pfu/mL,重组体百分比分别为99.3%和98.2%,插入片段的平均长度分别为2.0 kb和2.3 kb。
已成功构建了一个优良的cDNA表达文库,这将为移植研究和相关药物的临床前评估奠定坚实基础。