PCR-based approaches for identification of multi-copy transgene integration sites in mouse genome

Generation of transgenic mice by DNA microinjection has become one of the most important technologies in studying gene function in vivo. Random integration of transgene often results in insertional mutation which may complicate phenotype analysis of transgenic mice and/or create a good opportunity to study the function of endogenous gene. However, the utilization of these potentially valuable resources is hampered due to lack of efficient approaches for rapid identification of multi-copy transgene integration sites. Here we propose two PCR-based approaches to identifying transgene/genome junction sequences. The efficiency of these two strategies was tested in 9 independent transgenic mouse lines. Among them, the transgene in 8 mouse lines was clearly localized to certain chromosome regions. These rapid and efficient approaches will greatly facilitate the study of insertional mutation due to transgene integration.