title: Genomic integration of lambda EG10 transgene in gpt delta transgenic rodents.
abstract: BACKGROUND
  Transgenic gpt delta mouse and rat models were developed to perform gpt and Spi(-) assays for in vivo mutagenicity tests. The animals were established by integration of lambda EG10 phage DNA as a transgene into the genome. The inserted position of the transgene on chromosome was determined by fluorescent in situ hybridization and Southern blot analyses; however, the exact position and sequence of the inserted junction were not known. To identify the site and pattern of genomic integration of the transgene copies, genomic DNAs extracted from C57BL/6J gpt delta mice and F344 gpt delta rats were applied to whole genome sequencing and mate-pair analysis.
  
  
  RESULTS
  The result confirmed that multi-copy lambda EG10 transgenes are inserted at a single position in the mouse chromosome 17. The junction contains 70 bp of overlapped genomic sequences, and it has short homology at both ends. A copy number analysis suggested that the inserted transgenes may contain 41 head-to-tail junctions and 16 junctions of other types such as rearranged abnormal junctions. It suggested that the number of intact copies could be approximately 40 at maximum. In the F344 gpt delta rats, transgenes are inserted at a single position in the rat chromosome 4. The junction contains no overlapped sequence but 72-kb genomic sequence including one gene was deleted. The inserted transgenes may contain 15 head-to-tail junctions and two rearranged junctions. It suggested that the number of intact copies could be 14 at maximum. One germline base substitution in the gpt gene rescued from gpt delta rats was characterized.
  
  
  CONCLUSIONS
  The exact inserted positions of the lambda EG10 transgene in the genome of gpt delta transgenic rodents were identified. The copy number and arrangement of the transgene were analyzed. PCR primers for quick genotyping of gpt delta mice and rats have been designed.
authors.affiliation: Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Masumura
authors.affiliation: Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan ; Present address: Ajinomoto co., inc., Material Development & Application Labs, Research Institute For Bioscience Products & Fine Chemicals, 1-1 Suzuki-cho Kawasaki-ku, Kawasaki-shi, 210-8681 Kanagawa Japan.
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Sakamoto
authors.affiliation: Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan.
authors.forename: Wakako
authors.initials: W
authors.lastname: Kumita
authors.affiliation: Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan.
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Honma
authors.affiliation: Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan.
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Nishikawa
authors.affiliation: Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan ; Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Nohmi
keywords: Copy number analysis; Genomic rearrangement; Next generation sequencer; gpt delta mouse and rat