Acute aspiration pneumonia in common marmoset (Callithrix jacchus) with marmoset duodenal dilation syndrome: A case report.

A female common marmoset (Callithrix jachhus) suffered from weight loss exhibited tachypnea after anesthesia. We diagnosed marmoset duodenal dilation syndrome (MDDS) and aspiration pneumonia after post-anesthesia vomiting secondary to MDDS. If MDDS is suspected due to clinical symptoms such as weight loss, bloating, or vomiting, careful anesthesia and treatment of vomiting will be important to prevent aspiration pneumonia.

Differential manifestation of ocular phenotypes in TALEN-mediated p19arf knockout FVB/N and C57BL/6J mouse lines.

BACKGROUND: p19arf, primarily known as a tumor suppressor, has also been reported to play an essential role in normal development of mouse eyes. Consistently, lack of p19arf has been associated with ocular defects, but the mixed background of the knockout (KO) mouse strain used raised a concern on the accuracy of the phenotypes observed in association with the targeted gene due to genetic heterogeneity. OBJECT: We carried out a study to investigate into the effect of genetic background on the manifestation of p19arf KO associated phenotypes. METHODS: We characterized the phenotypes of novel p19arf KO mouse lines generated in FVB/N and C57BL/6J using a transcription activator-like effector nuclease (TALEN) system in comparison to the reported phenotypes of three other p19arf-deficient mouse lines generated using homologous recombination. RESULTS: Ninety-five percent of FVB/N-p19arf KO mice showed ocular opacity from week 4 after birth which worsened rapidly until week 6, while such abnormality was absent in C57BL/6J-p19arf KO mice up to the age of 26 weeks. Histopathological analysis revealed retrolental masses and dysplasia in the retinal layer in FVB/N-p19arf KO mice from week 4. Besides these, both strains developed normally from birth to week 26 without increased tumorigenesis except for a subcutaneous tumor found in a C57BL/6J-p19arf KO mouse. CONCLUSION: Our findings demonstrated surprisingly variable manifestation of p19arf-linked phenotypes between FVB/N and C57BL/6J mice, and furthermore between our mouse lines and the established lines, indicating a critical impact of genetic background on functional study of genes using gene targeting strategies in mice.

CRISPR/Cas9-mediated knockout of Rag-2 causes systemic lymphopenia with hypoplastic lymphoid organs in FVB mice.

Recombination activating gene-2 (RAG-2) plays a crucial role in the development of lymphocytes by mediating recombination of T cell receptors and immunoglobulins, and loss of RAG-2 causes severe combined immunodeficiency (SCID) in humans. RAG-2 knockout mice created using homologous recombination in ES cells have served as a valuable immunodeficient platform, but concerns have persisted on the specificity of RAG-2-related phenotypes in these animals due to the limitations associated with the genome engineering method used. To precisely investigate the function of RAG-2, we recently established a new RAG-2 knockout FVB mouse line (RAG-2 -/-) manifesting lymphopenia by employing a CRISPR/Cas9 system at Center for Mouse Models of Human Disease. In this study, we further characterized their phenotypes focusing on histopathological analysis of lymphoid organs. RAG-2 -/- mice showed no abnormality in development compared to their WT littermates for 26 weeks. At necropsy, gross examination revealed significantly smaller spleens and thymuses in RAG-2 -/- mice, while histopathological investigation revealed hypoplastic white pulps with intact red pulps in the spleen, severe atrophy of the thymic cortex and disappearance of follicles in lymph nodes. However, no perceivable change was observed in the bone marrow. Moreover, our analyses showed a specific reduction of lymphocytes with a complete loss of mature T cells and B cells in the lymphoid organs, while natural killer cells and splenic megakaryocytes were increased in RAG-2 -/- mice. These findings indicate that our RAG-2 -/- mice show systemic lymphopenia with the relevant histopathological changes in the lymphoid organs, suggesting them as an improved Rag-2-related immunodeficient model.

CRISPR/Cas9-mediated knockout of CD47 causes hemolytic anemia with splenomegaly in C57BL/6 mice.

CD47 (integrin-associated protein), a multi-spanning transmembrane protein expressed in all cells including red blood cells (RBCs) and leukocytes, interacts with signal regulatory protein α (SIRPα) on macrophages and thereby inhibits phagocytosis of RBCs. Recently, we generated a novel C57BL/6J CD47 knockout (CD47 -/- hereafter) mouse line by employing a CRISPR/Cas9 system at Center for Mouse Models of Human Disease, and here report their hematological phenotypes. On monitoring their birth and development, CD47 -/- mice were born viable with a natural male-to-female sex ratio and normally developed from birth through puberty to adulthood without noticeable changes in growth, food/water intake compared to their age and sex-matched wild-type littermates up to 26 weeks. Hematological analysis revealed a mild but significant reduction of RBC counts and hemoglobin in 16 week-old male CD47 -/- mice which were aggravated at the age of 26 weeks with increased reticulocyte counts and mean corpuscular volume (MCV), suggesting hemolytic anemia. Interestingly, anemia in female CD47 -/- mice became evident at 26 weeks, but splenomegaly was identified in both genders of CD47 -/- mice from the age of 16 weeks, consistent with development of hemolytic anemia. Additionally, helper and cytotoxic T cell populations were considerably reduced in the spleen, but not in thymus, of CD47 -/- mice, suggesting a crucial role of CD47 in proliferation of T cells. Collectively, these findings indicate that our CD47 -/- mice have progressive hemolytic anemia and splenic depletion of mature T cell populations and therefore may be useful as an in vivo model to study the function of CD47.

Purification and characterization of a copper-binding protein from Asian periwinkle Littorina brevicula.

The Asian periwinkle, Littorina brevicula, is highly resistant to a wide range of heavy metal concentrations and its metal-binding protein(s) are induced in the presence of cadmium (Cd) and zinc (Zn). In this study, we isolated and characterized a novel copper-binding protein (Cu-BP). Following purification by Sephacryl S-100 chromatography, Cu-BP contained an equal amount of Zn in non-exposed physiological conditions. However, Zn is replaced by Cu at the binding site upon addition of excess Cu (100 microM CuCl(2)) to the cytosol or after a long period (60 days) of exposure of the periwinkles to the metal ion (150 microg/l CuCl(2)). The ligand was further purified by DEAE-Sepharose anion-exchange chromatography and C(18) reverse-phase HPLC. The molecular weight of the purified protein was determined as 11.38 kDa by MALDI-TOF MS analyses. This Cu-BP is distinct from common mollusk metallothionein (MT) in that it contains significantly lower number of Cys (8 residues) and high levels of aromatic amino acids, Tyr and Phe. The protein additionally contains His and Met, which are absent in the MT-like Cd-BP of L. brevicula. The finding that Cu-BP in the Asian periwinkle is distinct from MT-like Cd-BP suggests that the timely expression of specific metal-binding proteins allows added protection against each heavy metal in severely polluted conditions.