Drosophila Histone Deacetylase-3 Controls Imaginal Disc Size through Suppression of Apoptosis

Histone deacetylases (HDACs) execute biological regulation through post-translational modification of chromatin and other cellular substrates. In humans, there are eleven HDACs, organized into three distinct subfamilies. This large number of HDACs raises questions about functional overlap and division of labor among paralogs. In vivo roles are simpler to address in Drosophila, where there are only five HDAC family members and only two are implicated in transcriptional control. Of these two, HDAC1 has been characterized genetically, but its most closely related paralog, HDAC3, has not. Here we describe the isolation and phenotypic characterization of hdac3 mutations. We find that both hdac3 and hdac1 mutations are dominant suppressors of position effect variegation, suggesting functional overlap in heterochromatin regulation. However, all five hdac3 loss-of-function alleles are recessive lethal during larval/pupal stages, indicating that HDAC3 is essential on its own for Drosophila development. The mutant larvae display small imaginal discs, which result from abnormally elevated levels of apoptosis. This cell death occurs as a cell-autonomous response to HDAC3 loss and is accompanied by increased expression of the pro-apoptotic gene, hid. In contrast, although HDAC1 mutants also display small imaginal discs, this appears to result from reduced proliferation rather than from elevated apoptosis. The connection between HDAC loss and apoptosis is important since HDAC inhibitors show anticancer activities in animal models through mechanisms involving apoptotic induction. However, the specific HDACs implicated in tumor cell killing have not been identified. Our results indicate that protein deacetylation by HDAC3 plays a key role in suppression of apoptosis in Drosophila imaginal tissue

Le preesistenze archeologiche. Il rilievo delle mura nascoste.

Lo studio è volto a ricostruire il tracciato della cinta muraria etrusca in corrispondenza del così detto Sopramuro, risultato della sistemazione medievale di questa zona urbana di Perugia. La muratura etrusca è stata intercettata in occasione i numerosi interventi condotti alla Soprintenenza per i Beni Archeologici dell'Umbria. I dati sono stati incrociati con i risultati delle ricerche georadar, videoendoscopio e laser scanner condotte dalla facoltà di ingegneria dell'Università degli Studi di Perugia.The study aims to reconstruct the path of the Etruscan walls at the so-called Sopramuro, the result of this arrangement medieval urban area of ​​Perugia. The Etruscan masonry was intercepted at the numerous interventions led to Soprintenenza for Archaeological Heritage of Umbria. The data were crossed with search results GPR, video endoscope and laser scanners conducted by the Faculty of Engineering of the University of Perugia

Enantioselective hydrolysis of epoxides: the employment of the soluble fraction from Vicia sativa seedlings

Biocatalytic hydrolysis of meso and racemic aryl- and alkyl-oxiranes was accomplished by employing the epoxide hydrolase activity of the soluble fraction of Vicia sativa seedlings. Whereas meso epoxides were not hydrolyzed by this fraction, racemic compounds were transformed into the corresponding diols by formal anti-stereoselective water attack. Both substrate and product enantioselectivity were strongly influenced by the chains length and the presence of a hydroxyl group. (C) 2001 Elsevier Science B.V. All rights reserved

Multicast Security and Reliable Transport of Rekey messages via satellite

The problems involved in multicast key distribution are discussed. Three protocols to accomplish such task are presented (one of them being designed by the authors) and their performances are compared

The dose of a putative ubiquitin-specific protease affects position-effect variegation in Drosophila melanogaster.

A dominant insertional P-element mutation enhances position-effect variegation in Drosophila melanogaster. The mutation is homozygous, viable, and fertile and maps at 64E on the third chromosome. The corresponding gene was cloned by transposon tagging. Insertion of the transposon upstream of the open reading frame correlates with a strong reduction of transcript level. A transgene was constructed with the cDNA and found to have the effect opposite from that of the mutation, namely, to suppress variegation. Sequencing of the cDNA reveals a large open reading frame encoding a putative ubiquitin-specific protease (Ubp). Ubiquitin marks various proteins, frequently for proteasome-dependent degradation. Ubps can cleave the ubiquitin part from these proteins. We discuss the link established here between a deubiquitinating enzyme and epigenetic silencing processes

The anomalous course of the microsomal transformation of the exo-2,3-epoxides of norbornene and norbornadiene. The possible involvement of a general acid activation during the enzymatic hydrolysis of these oxides

The enzymatic hydrolysis of exo-2,3-epoxy-norbornane (1) with a crude rabbit liver microsomal preparation occurred with a rearrangement and gave selectively (2 R,7S)-bicyclo[2.2.1]heptane-2,7-diol (3), enantiomeric excess (ee) 30 +/- 2%. The analogous exo-2,3-epoxy-5-norbornene (2) gave, under the same conditions, exclusively endo-6-hydroxymethylbicyclo-[3.1.0]hex-2-ene (4), arising from the microsomal catalyzed reduction of the first formed endo-6-formylbicyclo-[3.1.0]hex-2-ene (5). A mechanistic explanation for the observed products is proposed. (C) 2000 Elsevier Science B.V. All rights reserved

Social Innovation, Territorial Capital and LEADER Experiences in Andalusia (Spain) and in Molise (Italy)

Neo-endogenous approaches to local development in rural areas are today a question of important debate. In the implementation of rural development, it is very unlikely to find genuinely and exclusively endogenous policies. It is therefore advisable to set aside the overly simplistic distinction between exogenous and endogenous, and explore the outcomes of a hybrid version of these approaches, such as neo-endogenous development. This approach involves the active participation of local stakeholders, a process which, according to the literature, can be achieved via “social innovation”. Using in-depth interviews with stakeholders, the dynamics, actors and processes involved in social innovation are explored in two significant cases in Italy (Castel del Giudice) and Spain (Huéscar). These are remote, marginal municipalities with serious economic and social problems that have embarked on interesting paths towards development by harnessing both local territorial capital and external support