Generation of rat offspring derived from sperm cryopreserved/banked in the National BioResource Project for the rat followed by transportation to another institution

To preserve genetic resources efficiently in rats, sperm cryopreservation is essential. This study aimed to confirm the ability of cryopreserved and transported rat spermatozoa to fertilize through intrauterine insemination. The Komeda miniature rat Ishikawa is a mutant caused by the autosomal recessive mutation mri. The epididymal sperm was frozen with egg yolk medium and banked at the National BioResource Project (NBRP), Kyoto University. The sperm was transported to Azabu University, then thawed at 37℃. The thawed semen was inseminated into the uterine horns of recipients; its motility was around 10%. Seven of 15 inseminated female rats became pregnant and 13 live pups were born. The results indicate that rat spermatozoa cryopreserved at NBRP are capable of restoring genetic resources through intrauterine insemination. We also confirmed the usefulness of assisted reproductive technologies for the rat including sperm cryopreservation and intrauterine insemination

Suppressing TGFβ signaling in regenerating epithelia in an inflammatory microenvironment is sufficient to cause invasive intestinal cancer

Genetic alterations in the TGFβ signaling pathway in combination with oncogenic alterations lead to cancer development in the intestines. However, the mechanisms of TGFβ signaling suppression in malignant progression of intestinal tumors have not yet been fully understood. We have examined ApcΔ716 TGFβr2ΔIEC compound mutant mice that carry mutations in Apc and TGFβr2 genes in the intestinal epithelial cells. We found inflammatory microenvironment only in the invasive intestinal adenocarcinomas but not in noninvasive benign polyps of the same mice. We thus treated simple TGFβr2ΔIEC mice with dextran sodium sulfate (DSS) that causes ulcerative colitis. Importantly, these TGFβr2ΔIEC mice developed invasive colon cancer associated with chronic inflammation.Wealso found that TGFβ signaling is suppressed in human colitis-associated colon cancer cells. In the mouse invasive tumors, macrophages infiltrated and expressed MT1-MMP, causingMMP2activation. These results suggest that inflammatory microenvironment contributes to submucosal invasion of TGFβ signaling-repressed epithelial cells through activation of MMP2. We further found that regeneration was impaired in TGFβr2ΔIEC mice for intestinal mucosa damaged by DSS treatment or X-ray irradiation, resulting in the expansion of undifferentiated epithelial cell population. Moreover, organoids of intestinal epithelial cells cultured from irradiated TGFβr2ΔIEC mice formed "long crypts" in Matrigel, suggesting acquisition of an invasive phenotype into the extracellular matrix. These results, taken together, indicate that a simple genetic alteration in the TGFβ signaling pathway in the inflamed and regenerating intestinal mucosa can cause invasive intestinal tumors. Such a mechanism may play a role in the colon carcinogenesis associated with inflammatory bowel disease in humans

A Semidominant Mutation in an Arabidopsis Mitogen-Activated Protein Kinase Phosphatase-Like Gene Compromises Cortical Microtubule Organization

Reversible protein phosphorylation regulates many cellular processes, including the dynamics and organization of the microtubule cytoskeleton, but the events mediating it are poorly understood. A semidominant phs1-1 allele of the Arabidopsis thaliana PROPYZAMIDE-HYPERSENSITIVE 1 locus exhibits phenotypes indicative of compromised cortical microtubule functions, such as left-handed helical growth of seedling roots, defective anisotropic growth at low doses of microtubule-destabilizing drugs, enhancement of the temperature-sensitive microtubule organization1-1 phenotype, and less ordered and more fragmented cortical microtubule arrays compared with the wild type. PHS1 encodes a novel protein similar to mitogen-activated protein kinase (MAPK) phosphatases. In phs1-1, a conserved Arg residue in the noncatalytic N-terminal region is exchanged with Cys, and the mutant PHS1 retained considerable phosphatase activity in vitro. In mammalian MAPK phosphatases, the corresponding region serves as a docking motif for MAPKs, and analogous Arg substitutions severely inhibit the kinase–phosphatase association. Transgenic studies indicate that the phs1-1 mutation acts dominant negatively, whereas the null phs1-2 allele is recessive embryonic lethal. We propose that the PHS1 phosphatase regulates more than one MAPK and that a subset of its target kinases is involved in the organization of cortical microtubules

A set of highly informative rat simple sequence length polymorphism (SSLP) markers and genetically defined rat strains.

[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]

A set of highly informative rat simple sequence length polymorphism (SSLP) markers and genetically defined rat strains

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.</p