The regulation of Hox gene expression during animal development

Hox genes encode a family of transcriptional regulators that elicit distinct developmental programmes along the head-to-tail axis of animals. The specific regional functions of individual Hox genes largely reflect their restricted expression patterns, the disruption of which can lead to developmental defects and disease. Here, we examine the spectrum of molecular mechanisms controlling Hox gene expression in model vertebrates and invertebrates and find that a diverse range of mechanisms, including nuclear dynamics, RNA processing, microRNA and translational regulation, all concur to control Hox gene outputs. We propose that this complex multi-tiered regulation might contribute to the robustness of Hox expression during development

A Hox gene mutation that triggers Nonsense-mediated RNA decay and affects alternative splicing during Drosophila development

Nonsense mutations are usually assumed to affect protein function by generating truncated protein products. Nonetheless, it is now clear that these mutations affect not just protein synthesis but also messenger RNA stability. The surveillance mechanism responsible for the detection and degradation of 'nonsense' RNA messages is termed nonsense-mediated RNA decay (NMD). Essential biochemical components of the NMD machinery have been defined in several species. Here we identify the Drosophila orthologue of one of these factors, Upf1, and document its expression during embryogenesis. To test whether NMD acts during Drosophila development, we make use of a mutation that introduces a stop codon into a variably spliced exon of the Hox gene Ultrabithorax (Ubx). Using real-time quantitative RT-PCR we demonstrate that Ubx transcripts containing the premature stop codon are expressed at lower levels than their wild type counterpart. Unexpectedly, we also find that the same mutation significantly increases the levels of a Ubx splicing isoform that lacks the exon containing the premature termination codon. These findings indicate that NMD is operational during Drosophila development and suggest that nonsense mutations may affect development by altering the spectrum of splicing products formed, as well as by reducing or eliminating protein synthesis

Regional wage convergence in Spain : 1850-1930

Real wages PPP adjusted are used to analyse labour market integration in Spain. In contrast to earlier research analysing migration and nominal wages rates, our research seems to indicate that a well-integrated labour market had emerged in Spain by 1914 and substantial wage convergence happened from 1850 to 1914 with low rates of interna l migration. The shock of World War I and the subsequent globalisation backlash appear to disrupt this integrated market provoking a spectacular increase in wage differentials across regions and provinces. However, real wage convergence across Spanish provinces resumed powerfully over 1920s, this time accompanied by high internal migrations

Multi-ion sensing of dipolar noise sources in ion traps

Trapped-ion quantum platforms are subject to `anomalous' heating due to interactions with electric-field noise sources of nature not yet completely known. There is ample experimental evidence that this noise originates at the surfaces of the trap electrodes, and models assuming fluctuating point-like dipoles are consistent with observations, but the exact microscopic mechanisms behind anomalous heating remain undetermined. Here we show how a two-ion probe displays a transition in its dissipation properties, enabling experimental access to the mean orientation of the dipoles and the spatial extent of dipole-dipole correlations. This information can be used to test the validity of candidate microscopic models, which predict correlation lengths spanning several orders of mag- nitude. Furthermore, we propose an experiment to measure these effects with currently-available traps and techniques

Regional wage convergence in Spain : 1850-1930.

Real wages PPP adjusted are used to analyse labour market integration in Spain. In contrast to earlier research analysing migration and nominal wages rates, our research seems to indicate that a well-integrated labour market had emerged in Spain by 1914 and substantial wage convergence happened from 1850 to 1914 with low rates of interna l migration. The shock of World War I and the subsequent globalisation backlash appear to disrupt this integrated market provoking a spectacular increase in wage differentials across regions and provinces. However, real wage convergence across Spanish provinces resumed powerfully over 1920s, this time accompanied by high internal migrations.