Hippo signaling instructs ectopic but not normal organ growth.

The Hippo signaling pathway is widely considered a master regulator of organ growth because of the prominent overgrowth phenotypes caused by experimental manipulation of its activity. Contrary to this model, we show here that removing Hippo transcriptional output did not impair the ability of the mouse liver and Drosophila eyes to grow to their normal size. Moreover, the transcriptional activity of the Hippo pathway effectors Yap/Taz/Yki did not correlate with cell proliferation, and hyperactivation of these effectors induced gene expression programs that did not recapitulate normal development. Concordantly, a functional screen in Drosophila identified several Hippo pathway target genes that were required for ectopic overgrowth but not normal growth. Thus, Hippo signaling does not instruct normal growth, and the Hippo-induced overgrowth phenotypes are caused by the activation of abnormal genetic programs.

Functionality based method for simultaneous isolation of rodent hepatic sinusoidal cells.

Chronic liver disease is the result of long term exposure to viruses or toxins such as alcohol, fat and drugs, and forms the basis for the development of liver fibrosis and primary liver cancer. In vitro and in vivo models are key to study the pathways involved in chronic liver disease and for the development of therapeutics. 3D co-culture systems are becoming the in vitro standard, which requires freshly isolated primary hepatic cells. We developed a novel isolation method to simultaneously isolate liver sinusoidal endothelial cells (LSECs), Kupffer cells (KCs) and hepatic stellate cells (HSCs). The method exploits the scavenging activity of LSECs, the phagocytic capacity of KCs and the retinoid content of HSCs in vivo to enable direct processing by fluorescence-activated cell sorting without additional antibody binding and washing steps. UFACS3, for UV-FACS-based isolation of 3 non-parenchymal liver cell types, yields functional and pure LSECs (98 ± 1%), KCs (98 ± 1%) and HSCs (97 ± 3%), with less hands-on time from healthy and diseased rodent livers. This novel approach allows a fast and effective combined isolation of sinusoidal cells for further analysis.

Production of biodiesel from microalgae through biological carbon capture: a review.

Gradual increase in concentration of carbon dioxide (CO2) in the atmosphere due to the various anthropogenic interventions leading to significant alteration in the global carbon cycle has been a subject of worldwide attention and matter of potential research over the last few decades. In these alarming scenario microalgae seems to be an attractive medium for capturing the excess CO2 present in the atmosphere generated from different sources such as power plants, automobiles, volcanic eruption, decomposition of organic matters and forest fires. This captured CO2 through microalgae could be used as potential carbon source to produce lipids for the generation of biofuel for replacing petroleum-derived transport fuel without affecting the supply of food and crops. This comprehensive review strives to provide a systematic account of recent developments in the field of biological carbon capture through microalgae for its utilization towards the generation of biodiesel highlighting the significance of certain key parameters such as selection of efficient strain, microalgal metabolism, cultivation systems (open and closed) and biomass production along with the national and international biodiesel specifications and properties. The potential use of photobioreactors for biodiesel production under the influence of various factors viz., light intensity, pH, time, temperature, CO2 concentration and flow rate has been discussed. The review also provides an economic overview and future outlook on biodiesel production from microalgae.

An evolutionary shift in the regulation of the Hippo pathway between mice and flies.

The Hippo pathway plays a key role in controlling organ growth in many animal species and its deregulation is associated with different types of cancer. Understanding the regulation of the Hippo pathway and discovering upstream regulators is thus a major quest. Interestingly, while the core of the Hippo pathway contains a highly conserved kinase cascade, different components have been identified as upstream regulators in Drosophila and vertebrates. However, whether the regulation of the Hippo pathway is indeed different between Drosophila and vertebrates or whether these differences are due to our limited analysis of these components in different organisms is not known. Here we show that the mouse Fat4 cadherin, the ortholog of the Hippo pathway regulator Fat in Drosophila, does not apparently regulate the Hippo pathway in the murine liver. In fact, we uncovered an evolutionary shift in many of the known upstream regulators at the base of the arthropod lineage. In this evolutionary transition, Fat and the adaptor protein Expanded gained novel domains that connected them to the Hippo pathway, whereas the cell-adhesion receptor Echinoid evolved as a new protein. Subsequently, the junctional adaptor protein Angiomotin (Amot) was lost and the downstream effector Yap lost its PDZ-binding motif that interacts with cell junction proteins. We conclude that fundamental differences exist in the upstream regulatory mechanisms of Hippo signaling between Drosophila and vertebrates.

[The social dimension of tuberculosis in the City of Munich]. / Die soziale Dimension der Tuberkulose in der Stadt München.

Germany is a low-incidence country for tuberculosis, but there is no time for complacency. With an annual incidence of 10 per 100,000 population the City of Munich counts twice as many cases of tuberculosis compared to the national average. Reasons for the concentration of tuberculosis in big cities include the high proportion of migrants from countries with high prevalence of tuberculosis and from socioeconomically disadvantaged populations. Munich's population is growing fast and is expected to exceed 1.5 million in the near future. Migrants looking for employment now come predominantly from Romania, Bulgaria and Poland. The proportion of foreign born patients with tuberculosis increased over the last ten years from 49 to 80 %. Asylum seekers and migrants need special attention from the public tuberculosis services. The proportion of tuberculosis patients with social problems increased from 37 to 55 % over the last 6 years. Demands for medical and social support have increased and the case management is increasingly complex. In 2011 the ambulatory treatment of 6 immigrants was supervised by the public health services in Munich. Increasingly, uninsured patients from southeastern states of the European Union need medical treatment. In Europe the overall number of tuberculosis cases is decreasing. The proportion of multidrug-resistant (MDR) tuberculosis in Eastern Europe is alarming. 15 of worldwide 27 countries with the highest MDR load are located in the European Region. In Munich the number of MDR cases is still low at 1-4 cases each year. But duration, cost and side effects of therapy are strong barriers to treatment success. All patients have the right to get adequate diagnostic work-up and effective treatment no matter in which country they reside. To realize this request with cross-border control and care, is a big challenge to the public health service in a global perspective.

A non-cell-autonomous tumor suppressor role for Stat in eliminating oncogenic scribble cells.

Elucidating signaling events between tumor cells and their microenvironment is a major challenge in understanding cancer development. Drosophila melanogaster has emerged as an important tool for dissecting the genetic circuits tumors depend on because their imaginal discs, simple epithelia present in the larva, can be genetically manipulated to serve as models to study cancer mechanisms. Imaginal disc cells mutant for the tumor-suppressor gene scribble (scrib) lose apical-basal polarity and have the potential to form large neoplastic tumors. Interestingly, when scrib mutant (scrib(-)) cells are surrounded by normal cells the scrib(-) population is eliminated. However, the signals and mechanisms that cause the elimination of clones of scrib(-) cells are poorly understood. Here, we analyzed the role of Stat, a component of the JAK/STAT signaling pathway, in tissues with clones of scrib(-) cells. We found that Stat activity is required in normal cells for the elimination of neighboring scrib(-) cells. Importantly, these competitive defects of stat mutant cells are not simply due to defects in cell proliferation because even stat(-) cells manipulated to hyperproliferate are unable to eliminate scrib(-) cells. These data identify Stat activity as a critical determinant of whether or not a tissue can eliminate abnormal cells and provide an important step forward in understanding the complex network of signals operating in and around tumorigenic cells.

Health status and behaviors among adults residing in rural Dominican Republic.

INTRODUCTION: The rapidly increasing burden of chronic diseases linked to adequacy of healthcare services and individual health behaviors is a key determinant of global public health. Given demographic aging and the accompanying health transition, chronic diseases in low and middle income communities of the Dominican Republic are likely to increase significantly. The objective of this article was to report on efforts in surveillance of health conditions and behaviors in underserved rural Dominican communities. METHODS: A modified 30 item, language-sensitive health survey was randomly administered to 117 adult participants (18 years and older) during a health fair held at three rural villages from March to April 2009 in the rural San Cristobál region of the Dominican Republic. Descriptive analyses of select health conditions and behavior variables from all completed surveys were tabulated. RESULTS: Adult participant ages ranged from 18 to 79 years (mean ± standard deviation; 34.0 ± 2.1), height from 1.4 to 2.0 m (1.7 ± 0.1), weight from 41.8 to 100.0 kg (66.2 ± 1.7) and BMI from 15.2 to 46.2 (24.2 ± 0.7). Overall, 69.2% of the sample self-reported their general health status to be fair to poor. The top three chronic diseases included: high blood pressure (35.8%), diabetes (15.0%), and asthma (14.2%). In all, 33.4% reported current smoker status and 61.7% were classified as heavy alcohol drinkers. CONCLUSION: Considerable variation was found in the self-report of health conditions and behavioral characteristics among those individuals that attended the health fair. Documenting these important health indicators in the rural communities has the potential to inform the development of surveillance activities and prevention efforts for future health education interventions.

Drosophila in cancer research: to boldly go where no one has gone before.

Transformation and metastasis are complex processes that depend on integration of effects from multiple mutations. Modeling this complexity requires manipulating multiple genes in particular sub-populations of cells in vivo. This is technically challenging in mammalian model systems and has limited the rate of progress in understanding the effects of the complex aberrations present in cancer cells. In contrast, powerful genetic methods in the fruit fly Drosophila allow efficient generation and analysis of complex genotypes in defined cell populations. These methods are already fruitful in exploring the interactions among cancer mutations, and between cell populations that mimic the tumor microenvironment. In this issue of Oncogene, Willecke et al. (2011) describe the implementation of a novel genetic screen in Drosophila to identify genes required for tumor growth in vivo. This report illustrates the power of using Drosophila to perform systematic genome-wide genetic screens in complex genetic backgrounds and for the resulting data to inform our understanding of transformation and metastasis in human systems.

Color properties and structural phase transition in penta- and hexacoordinate isothiocyanato Ni(II) compounds.

We investigated the optical properties of (NBu(4))(3)[Ni(NCS)(5)], a pentacoordinate Ni compound, and compared the results with the more traditional hexacoordinate analogue (NEt(4))(4)[Ni(NCS)(6)]. On the basis of our complementary electronic structure calculations, the color properties of this high spin complex can be understood in terms of excitations between strongly hybridized orbitals with significant Ni d and ligand character. Variable temperature vibrational studies show mode softening with decreasing temperature and splitting near 200 K, trends that we attribute to improved low temperature intermolecular interactions and a weak structural phase transition, respectively.

Binding of the Vestigial co-factor switches the DNA-target selectivity of the Scalloped selector protein.

The formation and identity of organs and appendages are regulated by specific selector genes that encode transcription factors that regulate potentially large sets of target genes. The DNA-binding domains of selector proteins often exhibit relatively low DNA-binding specificity in vitro. It is not understood how the target selectivity of most selector proteins is determined in vivo. The Scalloped selector protein controls wing development in Drosophila by regulating the expression of numerous target genes and forming a complex with the Vestigial protein. We show that binding of Vestigial to Scalloped switches the DNA-binding selectivity of Scalloped. Two conserved domains of the Vestigial protein that are not required for Scalloped binding in solution are required for the formation of the heterotetrameric Vestigial-Scalloped complex on DNA. We suggest that Vestigial affects the conformation of Scalloped to create a wing cell-specific DNA-binding selectivity. The modification of selector protein DNA-binding specificity by co-factors appears to be a general mechanism for regulating their target selectivity in vivo.

Expression of the blistered/DSRF gene is controlled by different morphogens during Drosophila trachea and wing development.

The Drosophila serum response factor (DSRF) is expressed in the precursors of the terminal tracheal cells and in the future intervein territories of the third instar wing imaginal disc. Dissection of the DSRF regulatory region reveals that a single enhancer element, which is under the control of the fibroblast growth factor (FGF)-receptor signalling pathway, is sufficient to induce DSRF expression in the terminal tracheal cells. In contrast, two separate enhancers direct expression in distinct intervein sectors of the wing imaginal disc. One element is active in the central intervein sector and is induced by the Hedgehog signalling pathway. The other element is under the control of Decapentaplegic and is active in two separate territories, which roughly correspond to the intervein sectors flanking the central sector. Hence, each of the three characterized enhancers constitutes a molecular link between a specific territory induced by a morphogen signal and the localized expression of a gene required for the final differentiation of this territory.

Ectopic gene expression and homeotic transformations in arthropods using recombinant Sindbis viruses.

BACKGROUND: The morphological diversity of arthropods makes them attractive subjects for studying the evolution of developmental mechanisms. Comparative analyses suggest that arthropod diversity has arisen largely as a result of changes in expression patterns of genes that control development. Direct analysis of how a particular gene functions in a given species during development is hindered by the lack of broadly applicable techniques for manipulating gene expression. RESULTS: We report that the Arbovirus Sindbis can be used to deliver high levels of gene expression in vivo in a number of non-host arthropod species without causing cytopathic effects in infected cells or impairing development. Using recombinant Sindbis virus, we investigated the function of the homeotic gene Ultrabithorax in the development of butterfly wings and beetle embryos. Ectopic Ultrabithorax expression in butterfly forewing imaginal discs was sufficient to cause the transformation of characteristic forewing properties in the adult, including scale morphology and pigmentation, to those of the hindwing. Expression of Ultrabithorax in beetle embryos outside of its endogenous expression domain affected normal development of the body wall cuticle and appendages. CONCLUSIONS: The homeotic genes have long been thought to play an important role in the diversification of arthropod appendages. Using recombinant Sindbis virus, we were able to investigate homeotic gene function in non-model arthropod species. We found that Ultrabithorax is sufficient to confer hindwing identity in butterflies and alter normal development of anterior structures in beetles. Recombinant Sindbis virus has broad potential as a tool for analyzing how the function of developmental genes has changed during the diversification of arthropods.

twin of eyeless, a second Pax-6 gene of Drosophila, acts upstream of eyeless in the control of eye development.

The Drosophila Pax-6 gene eyeless (ey) plays a key role in eye development. Here we show tht Drosophila contains a second Pax-6 gene, twin of eyeless (toy), due to a duplication during insect evolution. Toy is more similar to vertebrate Pax-6 proteins than Ey with regard to overall sequence conservation, DNA-binding function, and early expression in the embryo, toy and ey share a similar expression pattern in the developing visual system, and targeted expression of Toy, like Ey, induces the formation of ectopic eyes. Genetic and biochemical evidence indicates, however, that Toy functions upstream of ey by directly regulating the eye-specific enhancer of ey. Toy is therefore required for initiation of ey expression in the embryo and acts through Ey to activate the eye developmental program.

Ultrabithorax function in butterfly wings and the evolution of insect wing patterns.

BACKGROUND: . The morphological and functional evolution of appendages has played a critical role in animal evolution, but the developmental genetic mechanisms underlying appendage diversity are not understood. Given that homologous appendage development is controlled by the same Hox gene in different organisms, and that Hox genes are transcription factors, diversity may evolve from changes in the regulation of Hox target genes. Two impediments to understanding the role of Hox genes in morphological evolution have been the limited number of organisms in which Hox gene function can be studied and the paucity of known Hox-regulated target genes. We have therefore analyzed a butterfly homeotic mutant 'Hindsight', in which portions of the ventral hindwing pattern are transformed to ventral forewing identity, and we have compared the regulation of target genes by the Ultrabithorax (Ubx) gene product in Lepidopteran and Dipteran hindwings. RESULTS: . We show that Ubx gene expression is lost from patches of cells in developing Hindsight hindwings, correlating with changes in wing pigmentation, color pattern elements, and scale morphology. We use this mutant to study how regulation of target genes by Ubx protein differs between species. We find that several Ubx-regulated genes in the Drosophila haltere are not repressed by Ubx in butterfly hindwings, but that Distal-less (Dll) expression is regulated by Ubx in a unique manner in butterflies. CONCLUSIONS: . The morphological diversification of insect hindwings has involved the acquisition of different sets of target genes by Ubx in different lineages. Changes in Hox-regulated target gene sets are, in general, likely to underlie the morphological divergence of homologous structures between animals.

Signaling by the TGF-beta homolog decapentaplegic functions reiteratively within the network of genes controlling retinal cell fate determination in Drosophila.

Retinal cell fate determination in Drosophila is controlled by an interactive network of genes, including eyeless, eyes absent, sine oculis and dachshund. We have investigated the role of the TGF-beta homolog decapentaplegic in this pathway. We demonstrate that, during eye development, while eyeless transcription does not depend on decapentaplegic activity, the expression of eyes absent, sine oculis and dachshund are greatly reduced in a decapentaplegic mutant background. We also show that decapentaplegic signaling acts synergistically with and at multiple levels of the retinal determination network to induce eyes absent, sine oculis and dachshund expression and ectopic eye formation. These results suggest a mechanism by which a general patterning signal such as Decapentaplegic cooperates reiteratively with tissue-specific factors to determine distinct cell fates during development.

The Vestigial and Scalloped proteins act together to directly regulate wing-specific gene expression in Drosophila.

A small number of major regulatory (selector) genes have been identified in animals that control the development of particular organs or complex structures. In Drosophila, the vestigial gene is required for wing formation and is able to induce wing-like outgrowths on other structures. However, the molecular function of the nuclear Vestigial protein, which bears no informative similarities to other proteins, was unknown. Here, we show that Vestigial requires the function of the Scalloped protein, a member of the TEA family of transcriptional regulators, to directly activate the expression of genes involved in wing morphogenesis. Genetic and molecular analyses reveal that Vestigial regulates wing identity by forming a complex with the Scalloped protein that binds sequence specifically to essential sites in wing-specific enhancers. These enhancers also require the direct inputs of signaling pathways, and the response of an enhancer can be switched to another pathway through changes in signal-transducer binding sites. Combinatorial regulation by selector proteins and signal transducers is likely to be a general feature of the tissue-specific control of gene expression during organogenesis.

Eyeless initiates the expression of both sine oculis and eyes absent during Drosophila compound eye development.

The Drosophila Pax-6 gene eyeless acts high up in the genetic hierarchy involved in compound eye development and can direct the formation of extra eyes in ectopic locations. Here we identify sine oculis and eyes absent as two mediators of the eye-inducing activity of eyeless. We show that eyeless induces and requires the expression of both genes independently during extra eye development. During normal eye development, eyeless is expressed earlier than and is required for the expression of sine oculis and eyes absent, but not vice versa. Based on the results presented here and those of others, we propose a model in which eyeless induces the initial expression of both sine oculis and eyes absent in the eye disc. sine oculis and eyes absent then appear to participate in a positive feedback loop that regulates the expression of all three genes. In contrast to the regulatory interactions that occur in the developing eye disc, we also show that in the embryonic head, sine oculis acts in parallel to eyeless and twin of eyeless, a second Pax-6 gene from Drosophila. Recent studies in vertebrate systems indicate that the epistatic relationships among the corresponding vertebrate homologs are very similar to those observed in Drosophila.

Ultrabithorax regulates genes at several levels of the wing-patterning hierarchy to shape the development of the Drosophila haltere.

Arthropods and vertebrates are constructed of many serially homologous structures whose individual patterns are regulated by Hox genes. The Hox-regulated target genes and developmental pathways that determine the morphological differences between any homologous structures are not known. The differentiation of the Drosophila haltere from the wing through the action of the Ultrabithorax (Ubx) gene is a classic example of Hox regulation of serial homology, although no Ubx-regulated genes in the haltere have been identified previously. Here, we show that Ubx represses the expression of the Wingless (Wg) signaling protein and a subset of Wg- and Decapentaplegic-activated genes such as spalt-related, vestigial, Serum Response Factor, and achaete-scute, whose products regulate morphological features that differ between the wing and haltere. In addition, we found that some genes in the same developmental pathway are independently regulated by Ubx. Our results suggest that Ubx, and Hox genes in general, independently and selectively regulate genes that act at many levels of regulatory hierarchies to shape the differential development of serially homologous structures.