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The phenotypic manifestations of increased expression of the Bap170 and e(y)3 (SAYP) genes in D. melanogaster were analyzed. Using the wing disc model, we show that moderate co-expression of Bap170 and e(y)3 genes in wing discs leads to abnormalities in wing veining. which was probably caused by suppression of EGFR/Ras/MAPK signaling pathways. Strong induction of co-expression of the above genes in wing discs leads to complete suppression of wing development in adults. Ubiquitous co-expression of Bap170 and e(y)3 is lethal at the 1st instar larval stage and leads to the formation of melanotic tumors. The above phenotypes are observed exclusively when Bap170 and e(y)3 are co-expressed. This evidence suggests a robust synergistic effect of the combined action of these genes, which is manifested in the hyperactivity of cell proliferation and differentiation. [ABSTRACT FROM AUTHOR]

This paper presents an attempt at the evaluation of the Alpine geoheritage of the Susa Valley (Piemonte region, NW Italy). The area is included in the project for the creation of the 'Cottian Alps Geopark', whose application to the European Geoparks Network is in progress. The Susa valley is a unique and great geological section showing all the structures and rocks involved in Alpine orogenesis. Moreover, it shows outstanding examples of interactions between human activities and processes of the physical environment. We considered these cultural landscapes as a heritage worthy to be known by people and to be exploited by geotourism activities. Therefore, we investigated the local geodiversity, assessed the geoheritage and identified the geosites characterised by a high potential for the enhancement of public understanding of geoscience and for recreational activities. In this paper, we describe the actions and methodologies carried on for creating geo-itineraries and for improving tourism activities and scientific knowledge. In particular, we focus attention on the Franks trail, a 60-km-long route crossing the Geopark territory, which follows the path blazed by Charlemagne in 773 AD as he attempted to avoid the Longobard army. The trail runs through many sites which tell about natural and cultural heritage. Our evaluation project makes the trail suitable as a 'cultural extension' of the 'Via GeoAlpina', an international project that aims to show the wonders of alpine geology and geomorphology. [ABSTRACT FROM AUTHOR]

The organization of chromosomes into euchromatin and heterochromatin is one of the most enigmatic aspects of genome evolution. For a long time, heterochromatin was considered to be a genomic wasteland, incompatible with gene expression. However, recent studies – primarily conducted in Drosophila melanogaster – have shown that this peculiar genomic component performs important cellular functions and carries essential genes. New research on the molecular organization, function and evolution of heterochromatin has been facilitated by the sequencing and annotation of heterochromatic DNA. About 450 predicted genes have been identified in the heterochromatin of D. melanogaster, indicating that the number of active genes is higher than had been suggested by genetic analysis. Most of the essential genes are still unknown at the molecular level, and a detailed functional analysis of the predicted genes is difficult owing to the lack of mutant alleles. Far from being a peculiarity of Drosophila, heterochromatic genes have also been found in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Oryza sativa and Arabidopsis thaliana, as well as in humans. The presence of expressed genes in heterochromatin seems paradoxical because they appear to function in an environment that has been considered incompatible with gene expression. In the future, genetic, functional genomic and proteomic analyses will offer powerful approaches with which to explore the functions of heterochromatic genes and to elucidate the mechanisms driving their expression.Heredity (2007) 98, 3–12. doi:10.1038/sj.hdy.6800877; published online 1 November 2006 [ABSTRACT FROM AUTHOR]

The conversion of pyruvoyl-H4-pterin to pyrimidodiazepine (PDA), which is an essential step in the biosynthesis of the red components of Drosophila eye pigments known as drosopterins, requires the products of the genes sepia and clot. While the product of sepia has been shown to correspond to the enzyme PDA-synthase, the role of clot remains unknown, although the clot 1 allele was one of the first eye-color mutants to be isolated in Drosophila melanogaster, and much genetic and biochemical data has become available since. Here we report the cloning of the clot gene, describe its molecular organization and characterize the sequence alterations associated with the alleles cl 1 and cl 2. The coding properties of the gene show that it encodes a protein related to the Glutaredoxin class of the Thioredoxin-like enzyme superfamily, conserved members of which are found in human, mouse and plants. We suggest that the Clot protein is an essential component of a glutathione redox system required for the final step in the biosynthetic pathway for drosopterins. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is a molecule involved in several signal transduction pathways leading either to proliferation or to cell death. Induction of ornithine decarboxylase (ODC), the key enzyme of polyamine biosynthesis, represents an early event preceding DNA synthesis. In some cell types increased ODC activity seems to be involved in cytotoxic response. We investigated the role of NO and ODC induction on the events linked to cell proliferation or to cell death in cultured chick embryo cardiomyocytes. Exposure of cardiomyocytes to tumor necrosis factor (TNF) and lipopolysaccharide (LPS) caused NO synthase (NOS) and ODC induction as well as increased incorporation of [3H]-thymidine. This last effect was blocked by a NOS inhibitor and was strongly reduced by difluoromethylornithine (DFMO), an irreversible inhibitor of ODC. Sodium nitroprusside (SNP), an exogenous NO donor, inhibited the increases of NOS and ODC activities and abolished the mitogenic effect of TNF and LPS. Moreover, SNP alone caused cell death in a dose dependent manner. The cytotoxicity of SNP was not affected by DFMO while it was prevented by antioxidants. The results suggest that different pathways would mediate the response of cardiomyocytes to NO: they can lead either to ODC induction and DNA synthesis when NO is formed through NOS induction or to growth inhibition and cell death, when NO is supplied as NO donor. Increased polyamine biosynthesis would mediate the proliferative response of NO, while the cytotoxicity of exogenous NO seems to involve some oxidative reactions and to depend on the balance between NO availability and cellular redox mechanisms. [ABSTRACT FROM AUTHOR]

The fusion process in heavy-ion systems is related to Coulomb scattering by using a simple physical picture underlying the modified SOD method. [ABSTRACT FROM AUTHOR]