zTrap and NIGKOF: the databases for gene trap/enhancer trap lines and gene-knockout fish lines

â—‹Koichi Kawakami1,2, Gembu Abe1, Kazuhide Asakawa1,2, Ryuichi Fukuda1, Pradeep Lal1, Akira Muto1, Hironori Wada1

1 Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan
2 Department of Genetics, Graduate University for Advanced Studies, Mishima, Japan

We have developed genetic methods by using the Tol2 transposable element, such as transgenesis, gene trapping, enhancer trapping and the Gal4FF-UAS method. By using these methods, we have been performing genetic screens to identify transgenic zebrafish that express GFP or Gal4FF in specific cells, tissues and organs. To date, we generated a collection of more than 800 lines. Furthermore, the transposon insertions in these fish were analyzed, and, to date, more than 500 integration sites were determined. These fish are extremely useful for studies of genetics, developmental biology and neurobiology. To further facilitate their availability, we developed a web-based database named zTrap (http://kawakami.lab.nig.ac.jp/). zTrap contains images of the expression patterns and the genomic information with the search functions. Therefore, researchers can easily find fish with expression patterns of interest and fish with transposon insertions near genes of interest. zTrap also contains the information about the UAS reporter and effector fish created in our lab. In the course of the screens, we have identified transgenic fish with multiple transposon insertions. To make the best use of such fish and to facilitate knock out of zebrafish genes, we collected male fish with multiple insertions, made frozen sperm stocks, and analyzed all of the insertions. Currently we found that 34% of the transposon insertions are located within annotated transcriptional units and 10% of the total insertions are located within exons, indicating that this approach is effective for insertional mutagenesis. We constructed a new database named NIGKOF and these data are available on NIGKOF.