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研究発表を行った学会； 熊本大学韓国フォーラム2006
　　　２００６年９月２６日〜２７日（韓国・大田）
タイトル； Database for the Exchangeable Gene Trap Clones.
発表者；　伊藤　美陽　氏
　　　（熊本大学　生命資源研究・支援センター　バイオ情報分野）
Abstract；
<Research background>
The Human Genome Project (HGP) had completed in 2003. The HGP is revealed that there are probably somewhere 22,000 human genes. All base sequences of various organisms are clarified one after another. An important focus of research in the post genome era is a study of how genes function within the body. The research that uses the mutant of model animal is useful to clarify the gene function in vivo. The mouse has been widely used a model animal to analyze the gene function because it is similar to human genetically and physiologically. Moreover, knocking out the activity of a gene is an effective method to analyze the gene function in vivo.

The gene trap is one of methods of the gene knockout. We can carry out random insertional mutagenesis and make various knockout mice efficiently. EGTC(Database for the Exchangeable Gene Trap Clones) is an official database of Gene Trap Project of Kumamoto University. 127 clones are registered in EGTC at present (July, 2006).

<About exchangeable gene trap>
The gene trap technique is a powerful approach for characterizing and mutating genes involved in mouse development. However one shortcoming of gene trapping is the relative inability to induce subtle mutations.
We have overcome this problem by introducing a knock-in system in the gene trap strategy and established the exchangeable gene trap vector, pU-Hachi, employing the Cre-mutated lox system.
[Kimi ARAKI, Masatake ARAKI and Ken-ichi Yamamura, Targeted integration of DNA using mutant lox sites in embryonic stem cells. Nucl. Acids Res., 25, 868-872 (1997).]
Since we found that there are some limitations in replacing patterns in pU-Hachi, we have constructed a new version of gene trap vector, pU-21.
Although the number of analyzed trap clones with pU-21 is not many, all ES cell lines have been confirmed for single copy integration and germ line transmission. Concerning for 5'-RACE results, we have also checked fusion mRNA of the trapped gene and reporter gene by RT-PCR using gene specific sense primer and antisense primer locating outside of RT primer used for RACE reaction.
In addition, mouse lines have been established from most of trap clones in this database and depositted to the CARD R-BASE; the database for cryopreserved embryos. Therefore, the trap lines can be provided in mouse or frozen embryos or sperm.