Cytological localization of adenosine kinase, nucleoside phosphorylase-1, and esterase-10 genes on mouse chromosome 14

We have determined the regional locations on mouse chromosome 14 of the genes for mouse adenosine kinase (ADK), nucleoside phosphorylase-1 (NP-1), and esterase-10 (ES-10) by analysis of rearranged mouse chromosomes in γ-irradiated Chinese hamster × mouse hybrid cell lines. Irradiated clones were screened for expression of the murine forms of these enzymes; segregant clones that expressed only one or two of the three markers were karyotyped. The patterns of enzyme expression in these segregants were correlated with the presence of rearranged chromosomes. The Adk gene was localized to bands A2 to B , Np-1 to bands B to C1, and Es-10 to bands D2 to E2 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45534/1/11188_2005_Article_BF01534704.pd

Adaptive immunity alters distinct host feeding pathways during nematode induced inflammation, a novel mechanism in parasite expulsion

Gastrointestinal infection is often associated with hypophagia and weight loss; however, the precise mechanisms governing these responses remain poorly defined. Furthermore, the possibility that alterations in feeding during infection may be beneficial to the host requires further study. We used the nematode Trichinella spiralis, which transiently inhabits the small intestine before migrating to skeletal muscle, as a biphasic model of infection to determine the cellular and molecular pathways controlling feeding during enteric and peripheral inflammation. Through the infection of genetically modified mice lacking cholecystokinin, Tumor necrosis factor α receptors and T and B-cells, we observed a biphasic hypophagic response to infection resulting from two separate immune-driven mechanisms. The enteroendocrine I-cell derived hormone cholecystokinin is an essential mediator of initial hypophagia and is induced by CD4+ T-cells during enteritis. In contrast, the second hypophagic response is extra-intestinal and due to the anorectic effects of TNFα during peripheral infection of the muscle. Moreover, via maintaining naive levels of the adipose secreted hormone leptin throughout infection we demonstrate a novel feedback loop in the immunoendocrine axis. Immune driven I-cell hyperplasia and resultant weight loss leads to a reduction in the inflammatory adipokine leptin, which in turn heightens protective immunity during infection. These results characterize specific immune mediated mechanisms which reduce feeding during intestinal or peripheral inflammation. Importantly, the molecular mediators of each phase are entirely separate. The data also introduce the first evidence that I-cell hyperplasia is an adaptively driven immune response that directly impinges on the outcome to infection

Molecular structure and genetic mapping of the mouse gastrin gene

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117035/1/feb20014579396004309.pd

Regulation of gastric epithelial cell homeostasis by gastrin and bone morphogenetic protein signaling

We reported that transgenic expression of the bone morphogenetic protein (BMP) signaling inhibitor noggin in the mouse stomach, leads to parietal‐cell (PC) loss, expansion of transitional cells expressing markers of both mucus neck and zymogenic lineages, and to activation of proliferative mechanisms. Because these cellular changes were associated with increased levels of the hormone gastrin, we investigated if gastrin mediates the expression of the phenotypic changes of the noggin transgenic mice (NogTG mice). Three‐month‐old NogTG mice were crossed to gastrin‐deficient (GasKO mice) to generate NogTG;GasKO mice. Morphology of the corpus of wild type, NogTG, GasKO, and NogTG;GasKO mice was analyzed by H&E staining. Distribution of PCs and zymogenic cells (ZCs) was analyzed by immunostaining for the H+/K+‐ATPase and intrinsic factor (IF). Expression of the H+/K+‐ATPase and IF genes and proteins were measured by QRT‐PCR and western blots. Cell proliferation was assessed by immunostaining for proliferating cell nuclear antigen. The corpus of the NogTG;GasKO mice displayed a marked reduction in the number of PCs and ZCs in comparison to NogTG mice. Further, cellular proliferation was significantly lower in NogTG;GasKO mice, than in the NogTG mice. Thus, gastrin mediates the increase in gastric epithelial cell proliferation induced by inhibition of BMP signaling in vivo. Moreover, gastrin and BMP signaling exert cooperative effects on the maturation and differentiation of both the zymogenic and PC lineages. These findings contribute to a better understanding of the factors involved in the control of gastric epithelial cell homeostasis.We investigated the role of gastrin and BMP signaling in the regulation of gastric epithelial homeostasis by crossing mice expressing the BMP inhibitor noggin in the stomach (NogTG mice) to gastrin‐deficient mice (GasKO mice). Analysis of these animals indicates that gastrin mediates the increase in gastric epithelial cell proliferation induced by inhibition of BMP signaling in vivo. Moreover, gastrin and BMP signaling exert cooperative effects on the maturation and differentiation of both the zymogenic and parietal‐cell lineages.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113157/1/phy212501.pd

Reproducibility and a unifying explanation: Lessons from the shape bias

The goal of science is to advance our understanding of particular phenomena. However, in the field of development, the phenomena of interest are complex, multifaceted, and change over time. Here, we use three decades of research on the shape bias to argue that while replication is clearly an important part of the scientific process, integration across the findings of many studies that include variations in procedure is also critical to create a coherent understanding of the thoughts and behaviors of young children. The “shape bias,” or the tendency to generalize a novel label to novel objects of the same shape, is a reliable and robust behavioral finding and has been shown to predict future vocabulary growth and possible language disorders. Despite the robustness of the phenomenon, the way in which the shape bias is defined and tested has varied across studies and laboratories. The current review argues that differences in performance that come from even seemingly minor changes to the participants or task can offer critical insight to underlying mechanisms, and that working to incorporate data from multiple labs is an important way to reveal how task variation and a child’s individual pathway creates behavior—a key issue for understanding developmental phenomena

TECHNICAL REPORT: Rapid confirmation of gene targeting in embryonic stem cells using two long-range PCR techniques

Gene targeting in mouse embryonic stem (ES) cells generally includes the analysis of numerous colonies to identify a few with mutations resulting from homologous recombination with a targeting vector. Thus, simple and efficient screening methods are needed to identify targeted clones. Optimal screening approaches require probes from outside of the region included in the targeting vector to avoid detection of the more common random insertions. However, the use of large genomic fragments in targeting vectors can limit the availability of cloned DNA, thus necessitating a strategy to obtain unique flanking sequences. We describe a rapid method to identify sequences adjacent to cloned DNA using long-range polymerase chain reaction (PCR) amplification from a genomic DNA library, followed by direct nucleotide sequencing of the amplified fragment. We have used this technique in two independent gene targeting experiments to obtain genomic DNA sequences flanking the mouse cholecystokinin (CCK) and gastrin genes. The sequences were then used to design primers to characterize ES cell lines with CCK or gastrin targeted gene mutations, employing a second long-range PCR approach. Our results show that these two long-range PCR methods are generally useful to rapidly and accurately characterize allele structures in ES cellsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43859/1/11248_2004_Article_172516.pd

Impact of dietary manganese on experimental colitis in mice

Diet plays a significant role in the pathogenesis of inflammatory bowel disease (IBD). A recent epidemiological study has shown an inverse relationship between nutritional manganese (Mn) status and IBD patients. Mn is an essential micronutrient required for normal cell function and physiological processes. To date, the roles of Mn in intestinal homeostasis remain unknown and the contribution of Mn to IBD has yet to be explored. Here, we provide evidence that Mn is critical for the maintenance of the intestinal barrier and that Mn deficiency exacerbates dextran sulfate sodium (DSS)â induced colitis in mice. Specifically, when treated with DSS, Mnâ deficient mice showed increased morbidity, weight loss, and colon injury, with a concomitant increase in inflammatory cytokine levels and oxidative and DNA damage. Even without DSS treatment, dietary Mn deficiency alone increased intestinal permeability by impairing intestinal tight junctions. In contrast, mice fed a Mnâ supplemented diet showed slightly increased tolerance to DSSâ induced experimental colitis, as judged by the colon length. Despite the wellâ appreciated roles of intestinal microbiota in driving inflammation in IBD, the gut microbiome composition was not altered by changes in dietary Mn. We conclude that Mn is necessary for proper maintenance of the intestinal barrier and provides protection against DSSâ induced colon injury.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154377/1/fsb220201_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154377/2/fsb220201-sup-0002-TableS3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154377/3/fsb220201-sup-0005-TableS6.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154377/4/fsb220201.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154377/5/fsb220201-sup-0003-TableS4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154377/6/fsb220201-sup-0004-TableS5.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154377/7/fsb220201-sup-0001-TableS1-S2.pd

The human amylase-encoding genes amy2 and amy3 are identical to AMY2A and AMY2B

Inspetion of the published nucleotide sequences reveals that the human amylase-encoding genes, amy2 and amy3, must be identical to the genes AMY2A and AMY2B, respectively.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27629/1/0000005.pd

Hedgehog Signaling Modulates Interleukinâ 33â Dependent Extrahepatic Bile Duct Cell Proliferation in Mice

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147852/1/hep41295_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147852/2/hep41295.pd

Notch signaling regulates gastric antral LGR5 stem cell function

The major signaling pathways regulating gastric stem cells are unknown. Here we report that Notch signaling is essential for homeostasis of LGR5+ antral stem cells. Pathway inhibition reduced proliferation of gastric stem and progenitor cells, while activation increased proliferation. Notch dysregulation also altered differentiation, with inhibition inducing mucous and endocrine cell differentiation while activation reduced differentiation. Analysis of gastric organoids demonstrated that Notch signaling was intrinsic to the epithelium and regulated growth. Furthermore, in vivo Notch manipulation affected the efficiency of organoid initiation from glands and single Lgr5‐GFP stem cells, suggesting regulation of stem cell function. Strikingly, constitutive Notch activation in LGR5+ stem cells induced tissue expansion via antral gland fission. Lineage tracing using a multi‐colored reporter demonstrated that Notch‐activated stem cells rapidly generate monoclonal glands, suggesting a competitive advantage over unmanipulated stem cells. Notch activation was associated with increased mTOR signaling, and mTORC1 inhibition normalized NICD‐induced increases in proliferation and gland fission. Chronic Notch activation induced undifferentiated, hyper‐proliferative polyps, suggesting that aberrant activation of Notch in gastric stem cells may contribute to gastric tumorigenesis.SynopsisThe Notch signaling pathway is required to maintain LGR5+ antral stem cells and epithelial cell homeostasis.Gastric antral stem cells display active Notch1 receptor signaling.Global Notch inhibition reduces stem and progenitor cell proliferation and increases differentiation of all lineages.Notch activation in LGR5+ stem cells increases stem and progenitor cell proliferation and inhibits differentiation.Notch activation enhances antral stem cell function, leading to tissue expansion via gland fission and tumor formation.The Notch signaling pathway is required to maintain LGR5+ antral stem cells and epithelial cell homeostasis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115949/1/embj201490583-sup-0002-EVFigs.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115949/2/embj201490583.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115949/3/embj201490583.reviewer_comments.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115949/4/embj201490583-sup-0001-Appendix.pd