Genetic variations regulate alternative splicing in the 5' untranslated regions of the mouse glioma-associated oncogene 1, Gli1

<p>Abstract</p> <p>Background</p> <p>Alternative splicing is one of the key mechanisms that generate biological diversity. Even though alternative splicing also occurs in the 5' and 3' untranslated regions (UTRs) of mRNAs, the understanding of the significance and the regulation of these variations is rather limited.</p> <p>Results</p> <p>We investigated 5' UTR mRNA variants of the mouse Gli1 oncogene, which is the terminal transcriptional effector of the Hedgehog (HH) signaling pathway. In addition to identifying novel transcription start sites, we demonstrated that the expression ratio of the Gli1 splice variants in the 5' UTR is regulated by the genotype of the mouse strain analyzed. The GT allele, which contains the consensus intronic dinucleotides at the 5' splice site of intron 1B, favors exon 1B inclusion, while the GC allele, having a weaker 5' splice site sequence, promotes exon 1B skipping. Moreover, the alternative Gli1 5' UTRs had an impact on translational capacity, with the shorter and the exon 1B-skipped mRNA variants being most effective.</p> <p>Conclusions</p> <p>Our findings implicate novel, genome-based mechanisms as regulators of the terminal events in the mouse HH signaling cascade.</p

Future aspects of X-ray emission from crystal undulators at channeling of positrons

In connection with ideas to produce undulator-like radiation in the hundreds of keV up to the MeV region by means of positron and electron channeling, there is renewed interest to study various channeling phenomena also experimentally. With electrons experiments have been performed at the Mainz Microtron MAMI to explore channeling-radiation emission by a 4-period epitaxially grown strained layer Si1−xGex undulator with a period length of λu = 9.9 μm. Unfortunately, high-quality positron beams of sufficient intensity are not easily accessible. The only serious candidate in Europe seems to be the Beam Test Facility (BTF) at INFN/LNF, Frascati, Italy. Some requirements to extent BTF in a facility which is also well suited for positron channeling-radiation experiments will be outlined

Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR

Simulation results for future measurements of electromagnetic proton form factors at \PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel $\bar p p \to e^+ e^-$ is studied on the basis of two different but consistent procedures. The suppression of the main background channel, $\textit{i.e.}$ $\bar p p \to \pi^+ \pi^-$, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance

Susceptibility of carrion crows to experimental infection with lineage 1 and 2 West Nile viruses

West Nile virus (WNV) outbreaks in North America have been characterized by substantial die-offs of American crows (Corvus brachyrhynchos). In contrast, a low incidence of bird deaths has been observed during WNV epidemic activity in Europe. To examine the susceptibility of the western European counterpart of American crows, we inoculated carrion crows (Corvus corone) with WNV strains isolated in Greece (Gr-10), Italy (FIN and Ita09), and Hungary (578/10) and with the highly virulent North American genotype strain (NY99). We also inoculated American crows with a selection of these strains to examine the strains’ virulence in a highly susceptible bird species. Infection with all strains, except WNV FIN, resulted in high rates of death and high-level viremia in both bird species and virus dissemination to several organs. These results suggest that carrion crows are highly susceptible to WNV and may potentially be useful as part of dead bird surveillance for early warning of WNV activity in Europe

Mixed marriages and transnational families in the intercultural context : a case study of African-Spanish couples in Catalonia, Spain

Premi a l'excel·lència investigadora. Àmbit de les Ciències Socials. 2008One of the consequences of international migration and the permanent settlement of immigrants in southern EU countries is the growing number of inter-country marriages and the formation of transnational families. Using both quantitative and qualitative data, this article examines patterns of endogamy and exogamy (i.e. marriage within/outside a particular group or category) among African immigrants in Catalonia, focusing on bi-national Senegalese- and Gambian-Spanish couples. Socio-demographic profiles, transnationality, the dynamics of cultural change or retention, and the formation of transcultural identities are explored. The evidence presented suggests that social-class factors are more important than cultural origins in patterns of endogamy and exogamy, in the dynamics of living together and in the bringing-up of children of mixed unions. Such a conclusion negates culturalists' explanations of endogamy and exogamy while, at the same time, emphasising the role of social actors as active subjects in these processes. I further argue that mixed couples and their offspring deal-to a greater or lesser extent-with multiple localisations and cultural backgrounds (i.e. here and there), rather than experiencing a 'clash between two cultures'. Therefore, it would be a mistake to pretend that multicultural links do not exist and that they cannot be revitalised and functional. The paper starts and ends by addressing the complexities of processes of interculturalism, resisting an interpretation of hybridity and segregation as contradictory or exclusive realities

Predation success by a plant-ant indirectly favours the growth and fitness of its host myrmecophyte

Mutualisms, or interactions between species that lead to net fitness benefits for each species involved, are stable and ubiquitous in nature mostly due to "byproduct benefits" stemming from the intrinsic traits of one partner that generate an indirect and positive outcome for the other. Here we verify if myrmecotrophy (where plants obtain nutrients from the refuse of their associated ants) can explain the stability of the tripartite association between the myrmecophyte Hirtella physophora, the ant Allomerus decemarticulatus and an Ascomycota fungus. The plant shelters and provides the ants with extrafloral nectar. The ants protect the plant from herbivores and integrate the fungus into the construction of a trap that they use to capture prey; they also provide the fungus and their host plant with nutrients. During a 9-month field study, we over-provisioned experimental ant colonies with insects, enhancing colony fitness (i.e., more winged females were produced). The rate of partial castration of the host plant, previously demonstrated, was not influenced by the experiment. Experimental plants showed higher δ¹⁵N values (confirming myrmecotrophy), plus enhanced vegetative growth (e.g., more leaves produced increased the possibility of lodging ants in leaf pouches) and fitness (i.e., more fruits produced and more flowers that matured into fruit). This study highlights the importance of myrmecotrophy on host plant fitness and the stability of ant-myrmecophyte mutualisms

Informal Interference in the Judiciary in New Democracies: A Comparison of Six African and Latin American Cases

This paper assesses the extent to which elected power holders informally intervene in the judiciaries of new democracies, an acknowledged but under-researched topic in studies of judicial politics. The paper first develops an empirical strategy for the study of informal interference based on perceptions recorded in interviews, then applies the strategy to six third-wave democracies, three in Africa (Benin, Madagascar and Senegal) and three in Latin America (Argentina, Chile and Paraguay). It also examines how three conditioning factors affect the level of informal judicial interference: formal rules, previous democratic experience, and socioeconomic development. Our results show that countries with better performance in all these conditioning factors exhibit less informal interference than countries with poorer or mixed performance. The results stress the importance of systematically including informal politics in the study of judicial politics