481 research outputs found
Drawing as Architecture: Representational Space Architecturally Transformed
This project was motivated by the premise that a drawing could take on architectural meaning beyond its initial performance as a re-presentation of an architectural idea; in other words, the motivation was to create a drawing that was architecture. When the drawing is the research, however, the conclusions found are necessarily different from the earliest goals pursued. There comes an understanding that a drawing may never be literal architecture; although, the means by which the drawing is created might be architectural or, at the very least, speak to ideals which are fundamental to the creation, to the process, of architecture
Loss of Atrx Affects Trophoblast Development and the Pattern of X-Inactivation in Extraembryonic Tissues
ATRX is an X-encoded member of the SNF2 family of ATPase/helicase proteins thought to regulate gene expression by modifying chromatin at target loci. Mutations in ATRX provided the first example of a human genetic disease associated with defects in such proteins. To better understand the role of ATRX in development and the associated abnormalities in the ATR-X (alpha thalassemia mental retardation, X-linked) syndrome, we conditionally inactivated the homolog in mice, Atrx, at the 8- to 16-cell stage of development. The protein, Atrx, was ubiquitously expressed, and male embryos null for Atrx implanted and gastrulated normally but did not survive beyond 9.5 days postcoitus due to a defect in formation of the extraembryonic trophoblast, one of the first terminally differentiated lineages in the developing embryo. Carrier female mice that inherit a maternal null allele should be affected, since the paternal X chromosome is normally inactivated in extraembryonic tissues. Surprisingly, however, some carrier females established a normal placenta and appeared to escape the usual pattern of imprinted X-inactivation in these tissues. Together these findings demonstrate an unexpected, specific, and essential role for Atrx in the development of the murine trophoblast and present an example of escape from imprinted X chromosome inactivation
Identification and quantification of myo-inositol hexakisphosphate in complex biological and environmental matrices using ion chromatography and high-resolution mass spectrometry in comparison to 31P NMR spectroscopy
CAPRI and RASAL impose different modes of information processing on Ras due to contrasting temporal filtering of Ca(2+)
The versatility of Ca(2+) as a second messenger lies in the complex manner in which Ca(2+) signals are generated. How information contained within the Ca(2+) code is interpreted underlies cell function. Recently, we identified CAPRI and RASAL as related Ca(2+)-triggered Ras GTPase-activating proteins. RASAL tracks agonist-stimulated Ca(2+) oscillations by repetitively associating with the plasma membrane, yet CAPRI displays a long-lasting Ca(2+)-triggered translocation that is refractory to cytosolic Ca(2+) oscillations. CAPRI behavior is Ca(2+)- and C2 domain–dependent but sustained recruitment is predominantly Ca(2+) independent, necessitating integration of Ca(2+) by the C2 domains with agonist-evoked plasma membrane interaction sites for the pleckstrin homology domain. Using an assay to monitor Ras activity in real time, we correlate the spatial and temporal translocation of CAPRI with the deactivation of H-Ras. CAPRI seems to low-pass filter the Ca(2+) signal, converting different intensities of stimulation into different durations of Ras activity in contrast to the preservation of Ca(2+) frequency information by RASAL, suggesting sophisticated modes of Ca(2+)-regulated Ras deactivation
Mutation of the diamond-blackfan anemia gene Rps7 in mouse results in morphological and neuroanatomical phenotypes.
The ribosome is an evolutionarily conserved organelle essential for cellular function. Ribosome construction requires assembly of approximately 80 different ribosomal proteins (RPs) and four different species of rRNA. As RPs co-assemble into one multi-subunit complex, mutation of the genes that encode RPs might be expected to give rise to phenocopies, in which the same phenotype is associated with loss-of-function of each individual gene. However, a more complex picture is emerging in which, in addition to a group of shared phenotypes, diverse RP gene-specific phenotypes are observed. Here we report the first two mouse mutations (Rps7(Mtu) and Rps7(Zma)) of ribosomal protein S7 (Rps7), a gene that has been implicated in Diamond-Blackfan anemia. Rps7 disruption results in decreased body size, abnormal skeletal morphology, mid-ventral white spotting, and eye malformations. These phenotypes are reported in other murine RP mutants and, as demonstrated for some other RP mutations, are ameliorated by Trp53 deficiency. Interestingly, Rps7 mutants have additional overt malformations of the developing central nervous system and deficits in working memory, phenotypes that are not reported in murine or human RP gene mutants. Conversely, Rps7 mouse mutants show no anemia or hyperpigmentation, phenotypes associated with mutation of human RPS7 and other murine RPs, respectively. We provide two novel RP mouse models and expand the repertoire of potential phenotypes that should be examined in RP mutants to further explore the concept of RP gene-specific phenotypes
Genome-Wide ENU Mutagenesis in Combination with High Density SNP Analysis and Exome Sequencing Provides Rapid Identification of Novel Mouse Models of Developmental Disease
BACKGROUND Mice harbouring gene mutations that cause phenotypic abnormalities during organogenesis are invaluable tools for linking gene function to normal development and human disorders. To generate mouse models harbouring novel alleles that are involved in organogenesis we conducted a phenotype-driven, genome-wide mutagenesis screen in mice using the mutagen N-ethyl-N-nitrosourea (ENU). METHODOLOGY/PRINCIPAL FINDINGS ENU was injected into male C57BL/6 mice and the mutations transmitted through the germ-line. ENU-induced mutations were bred to homozygosity and G3 embryos screened at embryonic day (E) 13.5 and E18.5 for abnormalities in limb and craniofacial structures, skin, blood, vasculature, lungs, gut, kidneys, ureters and gonads. From 52 pedigrees screened 15 were detected with anomalies in one or more of the structures/organs screened. Using single nucleotide polymorphism (SNP)-based linkage analysis in conjunction with candidate gene or next-generation sequencing (NGS) we identified novel recessive alleles for Fras1, Ift140 and Lig1. CONCLUSIONS/SIGNIFICANCE In this study we have generated mouse models in which the anomalies closely mimic those seen in human disorders. The association between novel mutant alleles and phenotypes will lead to a better understanding of gene function in normal development and establish how their dysfunction causes human anomalies and disease.This work was enabled by the Australian Phenomics Network and partly supported by funding from the Australian Government’s National Collaborative Research Infrastructure Strategy, a Strategic Grant from the Faculty of Medicine, Nursing and Health Sciences at Monash University, and the Victorian Government’s Operational Infrastructure Support Program. IS acknowledges support through the NH&MRC R. Douglas Wright and ARC Future Fellowship schemes. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Risk in the "Red Zone": Outcomes for Children Admitted to Ebola Holding Units in Sierra Leone Without Ebola Virus Disease.
We collected data on 1054 children admitted to Ebola Holding Units in Sierra Leone and describe outcomes of 697/1054 children testing negative for Ebola virus disease (EVD) and accompanying caregivers. Case-fatality was 9%; 3/630 (0.5%) children discharged testing negative were readmitted EVD-positive. Nosocomial EVD transmission risk may be lower than feared
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