Health monitoring of laboratory rodents not only improves animal health but also enhances the validity of animal experiments. In particular, infections of laboratory animals with murine parvoviruses influence biomedical research data. Despite strict barrier housing, prevalence remains high in animal facilities, leading to increased risk of parvovirus introduction after the import of contaminated mice.
View Article and Find Full Text PDFObesity has emerged as a major global health problem and is associated with various diseases, such as metabolic syndrome, type 2 diabetes mellitus, and cardiovascular diseases. The inbred C57BL/6 mouse strain is often used for various experimental investigations, such as metabolic research. However, over time, genetically distinguishable C57BL/6 substrains have evolved.
View Article and Find Full Text PDFHygienic monitoring of laboratory rodents has focused more and more on the analysis of environmental sample material by quantitative polymerase chain reaction (qPCR) assays. This approach requires profound knowledge of specific genetic sequences of the agents to be monitored and the assays need to be permanently adapted to take the latest research into account. [] was recently reclassified into the new genus , with and as the most commonly detected species in laboratory mouse colonies.
View Article and Find Full Text PDFGenetic analysis in the IL10-deficient mouse model revealed a modifier locus of experimental inflammatory bowel disease (IBD) on chromosome 18, with the allele of the strain C3H/HeJBir (C3Bir) conferring resistance and the allele of C57BL/6J (B6) conferring susceptibility. Differential Cd14 expression was associated with this background specific susceptibility to intestinal inflammation. Polymorphisms of the Cd14 promoter were found to be likely causative for strain specific expression, and Cd14-knockout mice revealed a protective role of this gene-product in experimental IBD.
View Article and Find Full Text PDFFeeder cells are essential for the establishment and culture of pluripotent rat embryonic stem cells (ESC) in vitro. Therefore, we tested several fibroblast and epithelial cell lines derived from the female genital tract as feeder cells to further improve ESC culture conditions. The immortalized tumor derived rat fibroblast TRF-O3 cells isolated from a Dnd1-deficient teratoma were identified as optimal feeder cells supporting stemness and proliferation of rat ESC.
View Article and Find Full Text PDFBackground: Engineered zinc-finger nucleases (ZFN) represented an innovative method for the genome manipulation in vertebrates. ZFN introduced targeted DNA double strand breaks (DSB) and initiated non-homologous end joining (NHEJ) after pronuclear or cytoplasmatic microinjection into zygotes. Resulting frame shift mutations led to functional gene ablations in zebra fish, mice, pigs and also in laboratory rats.
View Article and Find Full Text PDFA spontaneous mutation leading to the formation of congenital ovarian and testicular tumors was detected in the WKY/Ztm rat strain. The histological evaluation revealed derivatives from all three germ layers, thereby identifying these tumors as teratomas. Teratocarcinogenesis was accompanied by infertility and the underlying mutation was termed ter.
View Article and Find Full Text PDFPluripotent cells referred to as embryonic germ cells (EGCs) can be derived from the embryonic precursors of the mature gametes: the primordial germ cells (PGCs). A homozygous mutation (ter) of the dead-end homolog 1 gene (Dnd1) in the rat causes gonadal teratocarcinogenesis and sterility due to neoplastic transformation and loss of germ cells. We mated heterozygous ter/+ WKY-Dnd1(ter)/Ztm rats and were able to cultivate the first genital ridge-derived EGCs of the rat embryo at day 14.
View Article and Find Full Text PDFThe results obtained from the outer ear skin of female pigs (German Landrace) by light microscopy (LM), transmission electron microscopy (TEM), and cryo scanning electron microscopy (cryo SEM) methods, in particular relying on careful and artefact-free tissue processing, exhibited that the stratum superficiale dermidis of the auricle had a very homogeneous and compact construction, especially in one area (central dorsum auriculae). Based upon the important measurements made [average thickness of stratum superficiale dermidis: 94 (+/-16) microm, region A: 81 (+/-10); average thickness of collagen fibre bundles: 12 (+/-2) microm, region A: 13 (+/-0.5); average density of subepidermal capillaries: 3134 (+/-459) loops/cm2, region A: 3497 (+/-247)], this impression was confirmed by low standard deviations for all parameters, in comparison to marginal locations studied.
View Article and Find Full Text PDFCyclin E1 controls G1/S phase transition of the eukaryotic cell cycle. We report the impact of alternative spliced cyclin E1 isoforms on cell cycle regulation in hepatocytes. We show that expression of new cyclin E1 mRNA variants IN3, Delta4, and Delta5 is associated with retarded proliferation in murine hepatocellular carcinoma.
View Article and Find Full Text PDFBackground & Aims: Caspase-8 is the apical caspase essential for triggering Fas-induced apoptosis. In this study, we investigated caspase-8 expression in hepatocellular carcinomas (HCCs) using recently described HCC mouse models (c-myc and IgEGF transgenes).
Methods: HCCs were isolated from c-myc and IgEGF transgenic animals.
Based on a shrinkage-free methodical approach (special plastic resin embedding, frozen section technique) and histological routine staining, the thickness of the different skin layers was measured from 15 regions of the outer and the inner side of the porcine auricle. Mean thickness values were for the str. corneum: 19 microns outside/20 microns inside, vital epidermis without ridges: 52 microns outside/56 microns inside, dermis: 1175 microns outside/1112 microns inside, hypodermis: 1024 microns outside/741 microns inside, perichondrium: 295 microns outside/220 microns inside.
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