Gata6 Promotes GLI3 Repressor Activities in the Limb

Gli3 is a major regulator of Hedgehog signaling during limb development. In the anterior mesenchyme, GLI3 is proteolytically processed into GLI3R, a truncated repressor form that inhibits Hedgehog signaling. Although numerous studies have identified mechanisms that regulate Gli3 function in vitro, it is not completely understood how Gli3 function is regulated in vivo. In this study, we show a novel mechanism of regulation of GLI3R activities in limb buds by Gata6, a member of the GATA transcription factor family. We show that conditional inactivation of Gata6 prior to limb outgrowth by the Tcre deleter causes preaxial polydactyly, the formation of an anterior extra digit, in hindlimbs. A recent study suggested that Gata6 represses Shh transcription in hindlimb buds. However, we found that ectopic Hedgehog signaling precedes ectopic Shh expression. In conjunction, we observed Gata6 and Gli3 genetically interact, and compound heterozygous mutants develop preaxial polydactyly without ectopic Shh expression, indicating an additional prior mechanism to prevent polydactyly. These results support the idea that Gata6 possesses dual roles during limb development: enhancement of Gli3 repressor function to repress Hedgehog signaling in the anterior limb bud, and negative regulation of Shh expression. Our in vitro and in vivo studies identified that GATA6 physically interacts with GLI3R to facilitate nuclear localization of GLI3R and repressor activities of GLI3R. Both the genetic and biochemical data elucidates a novel mechanism by Gata6 to regulate GLI3R activities in the anterior limb progenitor cells to prevent polydactyly and attain proper development of the mammalian autopod

Sp8 exhibits reciprocal induction with Fgf8 but has an opposing effect on anterior-posterior cortical area patterning

Telencephalic patterning centers, defined by the discrete expression domains of distinct morphogens, Fgfs in the commissural plate (CoP), Wnts and Bmps in the cortical hem, and a ventral domain of Sonic hedgehog (Shh), are postulated to establish during development the initial patterning of the telencepahlon, including the neocortex. We show that the expression patterns of Sp5, Sp8, and Sp9, members of the Sp8-like family that are homologues of Drosophila buttonhead, correlate during early embryonic development with these three telencephalic patterning centers. To study potential functional relationships, we focused on Sp8, because it is transiently expressed in the CoP coincident with the expression of Fgf8, a morphogen implicated in area patterning of the neocortex. We also show that Sp8 is expressed in cortical progenitors in a high to low anterior-medial to posterior-lateral gradient across the ventricular zone. We used in utero electroporation of full-length and chimeric expression constructs to perform gain-of-function and loss-of-function studies of interactions between Sp8 and Fgf8 and their roles in cortical area patterning. We show that Fgf8 and Sp8 exhibit reciprocal induction in vivo in the embryonic telencephalon. Sp8 also induces downstream targets of Fgf8, including ETS transcription factors. In vitro assays show that Sp8 binds Fgf8 regulatory elements and is a direct transcriptional activator of Fgf8. We also show that Sp8 induction of Fgf8 is repressed by Emx2 in vitro, suggesting a mechanism to limit Fgf8 expression to the CoP. In vivo expression of a dominant negative Sp8 in the CoP indicates that Sp8 maintains expression of Fgf8 and also its effect on area patterning. Ectopic expression of Sp8 in anterior or posterior cortical poles induces significant anterior or posterior shifts in area patterning, respectively, paralleled by changes in expression of gene markers of positional identity. These effects of Sp8 on area patterning oppose those induced by ectopic expression of Fgf8, suggesting that in parallel to regulating Fgf8 expression, Sp8 also activates a distinct signaling pathway for cortical area patterning. In summary, Sp8 and Fgf8 robustly induce one another, and may act to balance the anterior-posterior area patterning of the cortex

Establishing teachers\u27personnel management system : Analyzing personnel exchanges between prefectural schools and boards of education

This paper clarifies the process in which the personnel exchanges between prefectural schools and boards of education are established, on the topic of Shimane Prefecture and Shizuoka Prefecture. In the former researches on teacher personnel affairs, only the relation between personnel exchange and promotion to the managerial position were pointed out. However, about the process until this relation is established as a career pattern, verification works were inadequate. By the investigation of this paper, the process that personnel exchanges were related with promotions to the managerial position of schools became clear. It was discovered that personnel exchanges were established as one of the personnel management systems of teachers by using two strategies. One is the strategy of promoting the teachers who experienced personnel exchange earlier than inexperienced teachers. Another is the strategy of promoting the teachers who experienced personnel exchange more mostly than the teachers who has not experienced. Although the latter was adopted only with the time whose number of schools increases, since the former is employable over a long period of time, its influence is more strong

The Factors that Influences the Personnel Management in Public Schools : Paying Attention to Environmental Restrictions and Strategies

This paper explains what kind of factors affect teachers\u27personnel management in public schools. Analyses in this paper are performed from both quantitative investigation and qualitative investigation. Concretely, econometric analysis was performed using the data obtained by question paper for prefectural personnel specializing in personnel affairs, and the case studies for one prefecture and one city were also performed. In these investigations, each prefecture has different geographical conditions and teachers\u27age composition, so they establish and employ the rules based on these conditions and their strategies of personnel management. And as the results of investigations, following points became clear. At first, these conditions and strategies determine the global image of teachers\u27personnel management. Moreover, in the second, in teachers\u27personnel management, the optimal arrangement in narrow areas and the optimal arrangement in large areas are not necessarily in agreement. These situations are seen also in other organizations, such as companies

<ORIGINAL>Combined Effects of Erbium : YAG laser and Fluoride Application on Acid Resistance of Tooth dentin in vitro

This study examined the inhibition of dentin demineralization in initial caries with Er : YAG laser irradiation only and laser irradiation combined with fluoride application. Dentin blocks were prepared from the roots of bovine incisors and pretreated with one of the following five procedures : A) untreated, B) Er : YAG laser irradiation for 5min at 50mJ/pulse, C) APF gel application for 5min, D) Er : YAG laser followed by APF application for 5min,and E) APF treatment for 5min followed by Er : YAG laser irradiation. Subsequently the samples were demineralized in a 0.1M lactic acid gel (pH5.0) containing 6wt% CMC at 37℃ for 2 weeks. The mineral distributions in the dentin surfaces were assessed quantitatively by transversal microradiography (TMR) and videodensitometry. The mineral parameter values were not significantly different for samples with and without laser treatment at p=0.05, as tested by paired t-tests. The present results suggest that the progress of demineralization in dentin lesions is not effectively inhibited by the single treatment with laser irradiation. Combined Er : YAG laser and APF treated samples had the highest acid resistance with significantly lower lesion depth (ld) and mineral loss (ΔZ) values lower even than the APF treated samples

Treatment with flunitrazepam of continuous spikes and waves during slow wave sleep (CSWS) in children

SummaryWe describe our treatment of two boys with continuous spikes and waves during slow wave sleep (CSWS). One of the boys was suffering from non-convulsive status epilepticus and the other from conscious disturbance with automatism. Their ictal EEG readings showed continuous diffuse spike and wave complexes, which were considered to show electrical status. The boys were diagnosed as having CSWS, and were later diagnosed with Landau–Kleffner syndrome (LKS). EEG readings returned to normal on intravenous injection of flunitazepam (FZP) at a dose of 0.02mg/kg, suggesting that FZP is an effective treatment for CSWS

Tuba8 Drives Differentiation of Cortical Radial Glia into Apical Intermediate Progenitors by Tuning Modifications of Tubulin C Termini

Most adult neurons and glia originate from radial glial progenitors (RGs), a type of stem cell typically extending from the apical to the basal side of the developing cortex. Precise regulation of the choice between RG self-renewal and differentiation is critical for normal development, but the mechanisms underlying this transition remain elusive. We show that the non-canonical tubulin Tuba8, transiently expressed in cortical progenitors, drives differentiation of RGs into apical intermediate progenitors, a more restricted progenitor type lacking attachment to the basal lamina. This effect depends on the unique C-terminal sequence of Tuba8 that antagonizes tubulin tyrosination and Δ2 cleavage, two post-translational modifications (PTMs) essential for RG fiber maintenance and the switch between direct and indirect neurogenesis and ultimately distinct neuronal lineage outcomes. Our work uncovers an instructive role of a developmentally regulated tubulin isotype in progenitor differentiation and provides new insights into biological functions of the cellular tubulin PTM “code.” Radial glial progenitors of the developing mouse cortex differentiate into a more restricted progenitor type, apical intermediate progenitors. Ramos et al. find that Tuba8 drives this differentiation by tuning tyrosination and Δ2 cleavage, post-translational modifications of tubulin C termini, highlighting the functional significance of the “tubulin code” in cortical progenitor differentiation.Fil: Ramos, Susana I.. King's College London; Reino UnidoFil: Makeyev, Eugene V.. King's College London; Reino UnidoFil: Salierno, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Kodama, Takashi. University Johns Hopkins; Estados UnidosFil: Kawakami, Yasuhiko. University Johns Hopkins; Estados UnidosFil: Sahara, Setsuko. King's College London; Reino Unid

Designer TGFβ Superfamily Ligands with Diversified Functionality

Transforming Growth Factor – beta (TGFβ) superfamily ligands, including Activins, Growth and Differentiation Factors (GDFs), and Bone Morphogenetic Proteins (BMPs), are excellent targets for protein-based therapeutics because of their pervasiveness in numerous developmental and cellular processes. We developed a strategy termed RASCH (Random Assembly of Segmental Chimera and Heteromer), to engineer chemically-refoldable TGFβ superfamily ligands with unique signaling properties. One of these engineered ligands, AB208, created from Activin-βA and BMP-2 sequences, exhibits the refolding characteristics of BMP-2 while possessing Activin-like signaling attributes. Further, we find several additional ligands, AB204, AB211, and AB215, which initiate the intracellular Smad1-mediated signaling pathways more strongly than BMP-2 but show no sensitivity to the natural BMP antagonist Noggin unlike natural BMP-2. In another design, incorporation of a short N-terminal segment from BMP-2 was sufficient to enable chemical refolding of BMP-9, without which was never produced nor refolded. Our studies show that the RASCH strategy enables us to expand the functional repertoire of TGFβ superfamily ligands through development of novel chimeric TGFβ ligands with diverse biological and clinical values

Tbx2 and Tbx3 Regulate the Dynamics of Cell Proliferation during Heart Remodeling

BACKGROUND: The heart forms from a linear tube that is subject to complex remodeling during embryonic development. Hallmarks of this remodeling are the looping of the heart tube and the regionalization into chamber and non-chamber myocardium. Cardiomyocytes in the future chamber myocardium acquire different cellular and physiological characteristics through activation of a chamber-specific genetic program, which is in part mediated by T-box genes. METHODOLOGY/PRINCIPAL FINDING: We characterize two new zebrafish T-box transcription factors, tbx3b and tbx2a, and analyze their role during the development of the atrioventricular canal. Loss- and gain-of-function analyses demonstrate that tbx3b and tbx2a are necessary to repress the chamber-genetic program in the non-chamber myocardium. We also show that tbx3b and tbx2a are required to control cell proliferation in the atrioventricular canal and that misregulation of cell proliferation in the heart tube influences looping. Furthermore, we characterize the heart phenotype of a novel Tbx3 mutation in mice and show that both the control of cell proliferation and the repression of chamber-specific genetic program in the non-chamber myocardium are conserved roles of Tbx3 in this species. CONCLUSIONS/SIGNIFICANCE: Taken together, our results uncover an evolutionarily conserved role of Tbx2/3 transcription factors during remodeling of the heart myocardium and highlight the importance of controlling cell proliferation as a driving force of morphogenesis