Rat ENU Mutagenesis - Information on the Kyoto University Rat Mutant Archive (KURMA)
Rat ENU mutagenesis

Chemical mutagenesis is a powerful tool to produce genetically modified mutations in many species, especially where no functional embryonic stem cell lines exist. At the present time, ENU (N-ethyl N-nitrosourea) mutagenesis followed by a screening method to detect single nucleotide substitutions within the targeted gene appears to be the most promising technology in rats. We have developed a novel, efficient approach that combines two methods: a high-throughput, low-cost screening assay which makes use of the Mu-transposition reaction (MuT-POWER); and, intracytoplasmic sperm injection (ICSI) for the recovery of the rare heterozygous genotypes from our newly generated frozen sperm repository, the Kyoto University Rat Mutant Archive (KURMA).

An ENU-induced mutant archive for gene targeting in rats.
Mashimo T. et al, Nat Genet. 40(5):514-515, 2008

The priciple workflow of the ENU program is shown in the picture below:

ENU scheme

ENU is injected intraperitoneally using a split dose of 2 x 40 mg/kg into 9 and 10 weeks old male F344/NSlc rats. These males are mated 10 weeks after the second ENU injection. DNA and sperm of their offspring (G1) are stored at the Kyoto University Rat Mutant Archive (KURMA). The screening technique MuT-POWER can be applied to the DNA of the archive at any given time in the future and in case of successful mutation detection, intracytoplasmic sperm injection (ICSI) is used to derive viable offspring from the G1 sperms.


A missense mutation of the gene encoding voltage-dependent sodium channel (Nav1.1) confers susceptibility to febrile seizures in rats.
Mashimo T, Ohmori I, Ouchida M, Ohno Y, Tsurumi T, Miki T, Wakamori M, Ishihara S, Yoshida T, Takizawa A, Kato M, Hirabayashi M, Sasa M, Mori Y, Serikawa T.
J Neurosci. 2010 Apr 21;30(16):5744-53.

Enhanced colitis-associated colon carcinogenesis in a novel Apc mutant rat.
Yoshimi K, Tanaka T, Takizawa A, Kato M, Hirabayashi M, Mashimo T, Serikawa T, Kuramoto T.
Cancer Sci. 100(11): 2022-2027, 2009

Rat resources in biomedical research.
Mashimo T, Serikawa T.
Curr Pharm Biotechnol. 10(2):214-220, 2009

Progress and prospects in rat genetics: a community view.
Aitman TJ, Critser JK, Cuppen E, Dominiczak A, Fernandez-Suarez XM, Flint J, Gauguier D, Geurts AM, Gould M, Harris PC, Holmdahl R, Hubner N, Izsvák Z, Jacob HJ, Kuramoto T, Kwitek AE, Marrone A, Mashimo T, Moreno C, Mullins J, Mullins L, Olsson T, Pravenec M, Riley L, Saar K, Serikawa T, Shull JD, Szpirer C, Twigger SN, Voigt B, Worley K.
Nat Genet. 40(5):516-522, 2008

An ENU-induced mutant archive for gene targeting in rats.
Mashimo T, Yanagihara K, Tokuda S, Voigt B, Takizawa A, Nakajima R, Kato M, Hirabayashi M, Kuramoto T, Serikawa T.
Nat Genet. 40(5):514-515, 2008

Kyoto University Rat Mutant Archive - KURMA