Genetic Quality Control of the Rat Strains at the National Bio Resource Project-Rat

Abstract

Abstract The National Bio Resource Project-Rat (NBRP-Rat) comprises the largest bank of laboratory rat ( Rattus norvegicus ) strains in the world. Its main focus is to develop infrastructure that will facilitate the systematic collection, preservation, and provision of rat strains. As of the end of September, 2010, more than 600 strains have been collected and preserved. Among them, 180 are maintained as living animal stocks. It is necessary to carry out a fast and reliable genetic diagnosis of mutations that each animal possesses to breed it effectively. In addition, a genetic monitoring system is needed to ensure its genetic quality. Here, we show the genetic control system of the NBRP-Rat in which a systematic set of genetic diagnoses and genetic monitoring is established. Genetic monitoring is performed by using 20 polymorphic markers. Monitoring is carried out when a living animal stock is re-established by using cryopreserved embryos or sperm or when a rat strain is first introduced to the NBRP-Rat by a depositor. Additional monitoring is then carried out on each strain every two years and each resulting genetic profile is compared with the original profile. Genetic diagnosis is performed largely by employing the Amp-FTA method. Protocols which detail how to perform a genetic diagnosis of 11 transgenes and 24 mutations have been made. Among the mutations, nine can be detected by simple gel electrophoresis of the PCR products, 11 by restriction enzyme treatment of the PCR products, and four by direct PCR product sequencing. As of the end of March, 2010, a total of 288 genetic profiles from 154 strains had been obtained and 16,812 samples had been subjected to genetic diagnosis. Furthermore, we reported on identifying a coat color mutation and a hairless mutation that is harbored by the mutant strains which are preserved at the NBRP-Rat. Using this genetic control system, the NBRP-Rat can guarantee the genetic quality of its rat strains. These rat strains are excellent model systems for biomedical research.