ABSTRACT
BACKGROUND: The National Bio Resource Project for the Rat in Japan (NBRP-Rat) is focusing on collecting, preserving and distributing various rat strains, including spontaneous mutant, transgenic, congenic, and recombinant inbred (RI) strains. To evaluate their value as models of human diseases, we are characterizing them using 109 phenotypic parameters, such as clinical measurements, internal anatomy, metabolic parameters, and behavioral tests, as part of the Rat Phenome Project. Here, we report on a set of 357 simple sequence length polymorphism (SSLP) markers and 122 rat strains, which were genotyped by the marker set. RESULTS: The SSLP markers were selected according to their distribution patterns throughout the whole rat genome with an average spacing of 7.59 Mb. The average number of informative markers between all possible pairs of strains was 259 (72.5% of 357 markers), showing their high degree of polymorphism. From the genetic profile of these rat inbred strains, we constructed a rat family tree to clarify their genetic background. CONCLUSION: These highly informative SSLP markers as well as genetically and phenotypically defined rat strains are useful for designing experiments for quantitative trait loci (QTL) analysis and to choose strategies for developing new genetic resources. The data and resources are freely available at the NBRP-Rat web site 1.
Subject(s)
Polymorphism, Genetic/genetics , Rats, Inbred Strains/genetics , Rats, Mutant Strains/genetics , Animals , Animals, Congenic/genetics , Animals, Genetically Modified/genetics , Breeding , Crosses, Genetic , Female , Genetic Markers , Genome , Genotype , Japan , Male , Phenotype , Phylogeny , Rats , Rats, Inbred Strains/classification , Rats, Mutant Strains/classification , Specific Pathogen-Free OrganismsSubject(s)
Androgen-Insensitivity Syndrome/genetics , Breeding , Genotype , Rats, Mutant Strains/classification , Rats, Mutant Strains/genetics , Animals , Base Sequence , DNA/blood , DNA/chemistry , Deoxyribonucleases, Type II Site-Specific/metabolism , Female , Genes, sry/genetics , Heterozygote , Male , Molecular Sequence Data , Mutation , Polymerase Chain Reaction , Rats , Receptors, Androgen/geneticsABSTRACT
Mouse hepatoma x rat hepatocyte hybrids that segregate rat chromosomes were used to determine the chromosomal location of the rat genes encoding 11 beta-hydroxylase and aldosterone synthase (Cyp11b1 and Cyp11b2 respectively). By means of species-specific restriction fragments and microsatellite markers both genes were mapped to rat chromosome 7. The Cyp11b1 microsatellite marker was subsequently found to vary in length between and within rat strains. Furthermore, we compared the sequences of Cyp11b1 markers in two genetically hypertensive strains of rat with their normotensive counterparts. Previous studies have indicated that 11 beta-hydroxylase activities in Milan and Lyon hypertensive strains are different from their respective genetic controls. The Cyp11b1 microsatellite regions from Lyon hypotensive and normotensive strains of rat were similar and were both shorter by 15 bases than that of the Lyon hypertensive strain. The Cyp11b1 marker in Milan hypertensive (MHS) and normotensive (MNS) strains differ from all the Lyon strains and from each other. The MHS marker is 12 bases shorter than that of MNS rats. These differences in microsatellite length may provide useful polymorphic markers in cosegregation studies of genetic hypertension in rats.
Subject(s)
Chromosome Mapping , Cytochrome P-450 Enzyme System/genetics , DNA, Satellite/genetics , Hypertension/genetics , Polymorphism, Genetic , Rats, Mutant Strains/genetics , Steroid 11-beta-Hydroxylase/genetics , Animals , Base Sequence , Cytochrome P-450 CYP11B2 , Genes , Hybrid Cells , Hypertension/physiopathology , Hypotension/genetics , Hypotension/physiopathology , Liver/cytology , Liver Neoplasms, Experimental/pathology , Mice , Molecular Sequence Data , Polymerase Chain Reaction , Rats , Rats, Mutant Strains/classification , Rats, Sprague-Dawley , Species SpecificityABSTRACT
Several techniques for the identification of the young obese Zucker rat were developed and tested. A procedure utilizing biopsies of hypodermal adipocytes was successful in identifying the obese phenotype in large litters of 7-d and older rats. This technique involves sizing and counting fat cells in esterase stained cryostat sections of skin biopsies. Another procedure involved measuring times to cessation of spontaneous activity upon acute exposure to a cold environment. As early as 3 d, obese rats become inactive (in the cold) in a significantly shorter time when compared to the lean rat. This technique was not a discriminating test for the identification of the obese genotype at 3 d of age. A preliminary analysis of brown fat histology and histochemistry indicated larger and more lipid filled brown adipocytes in the obese animal when compared to lean animals at 10 and 14 d of age. Brown fat from young obese animals was histochemically similar to brown fat in lean rats.
