First record of a tropical shallow water barnacle Tetraclita sp. (Cirripedia: Tetraclitoidea) from the middle Neogene of the Canary Islands

This paper describes the first record of the intertidal, tropical tetraclitoid barnacle Tetraclita sp. cf. T. stalactifera (Lamarck, 1818) from the middle Neogene of the Canary Islands. The barnacles were recovered as isolated plates from a bioclastic volcanic agglomerate. Associated fauna in- cludes patellid and neritid gastropods, and an oyster bank, which confirm a shallow-water litoral setting. Living Tetraclita stalactifera is recorded from tropical waters of the America, South Africa and the Arabian Sea; it is first recorded as fossil from Plio-Pleistocene of Curaçao (Caribbean Sea, Venezuela)

The Escherichia coli RnlA–RnlB toxin–antitoxin complex: production, characterization and crystallization

The Escherichia coli rnlAB operon encodes a toxin–antitoxin module that is involved in protection against infection by bacteriophage T4. The full-length RnlA–RnlB toxin–antitoxin complex as well as the toxin RnlA were purified to homogeneity and crystallized. When the affinity tag is placed on RnlA, RnlB is largely lost during purification and the resulting crystals exclusively comprise RnlA. A homogeneous preparation of RnlA–RnlB containing stoichiometric amounts of both proteins could only be obtained using a His tag placed C-terminal to RnlB. Native mass spectrometry and SAXS indicate a 1:1 stoichiometry for this RnlA–RnlB complex. Crystals of the RnlA–RnlB complex belonged to space group C2, with unit-cell parameters a = 243.32, b = 133.58, c = 55.64 Å, β = 95.11°, and diffracted to 2.6 Å resolution. The presence of both proteins in the crystals was confirmed and the asymmetric unit is likely to contain a heterotetramer with RnlA2:RnlB2 stoichiometry

Morpho-environmental characterization of the genus Baldellia Parl. (Alismataceae) in the Iberian Peninsula, Balearic islands and North Morocco

The genus Baldellia Parl. has always been a complex taxon. Three species and three subspecies have been proposed for the Iberian Peninsula. The morphological variation of this genus in the Iberian Peninsula, Balearic islands and northern Morocco, and its thermo-pluviometric and altitudinal correlation are the focus of this contribution. Twenty-eight morphological variables were examined and subjected to a multivariate statistical analysis. The three morphotypes observed (Form 1, which includes B. ranunculoides subsp. repens and B. alpestris; Form 2, which includes B. ranunculoides and Form 3 for the new combination B. ranunculoides subsp. ranunculoides var. tangerina (Pau) J. Rocha, A. Crespi, M. Garcia-Barriuso, R. Almeida, J. Honrado, comb. nova proposed here for the first time) seem to represent different reproductive strategies. Morphological variables related with the presence or absence of stolons and the architecture of the inflorescence; the size and number of fruits are the most discriminating variables. Form 1 represents the asexual morphotype; Forms 2 and 3 correspond to morphotypes for which sexual reproduction is preferential. The environmental approach revealed that the asexual form (Form 1) grows in temperate, in more humid conditions, and within a broad altitudinal range. In contrast, the two sexual forms are more common in warmer and drier conditions, and occur over a narrower interval of altitudes

A dual role in regulation and toxicity for the disordered N-terminus of the toxin GraT.

Bacterial toxin-antitoxin (TA) modules are tightly regulated to maintain growth in favorable conditions or growth arrest during stress. A typical regulatory strategy involves the antitoxin binding and repressing its own promoter while the toxin often acts as a co-repressor. Here we show that Pseudomonas putida graTA-encoded antitoxin GraA and toxin GraT differ from other TA proteins in the sense that not the antitoxin but the toxin possesses a flexible region. GraA auto-represses the graTA promoter: two GraA dimers bind cooperatively at opposite sides of the operator sequence. Contrary to other TA modules, GraT is a de-repressor of the graTA promoter as its N-terminal disordered segment prevents the binding of the GraT2A2 complex to the operator. Removal of this region restores operator binding and abrogates Gr aT toxicity. GraTA represents a TA module where a flexible region in the toxin rather than in the antitoxin controls operon expression and toxin activity

Phosphorylation decelerates conformational dynamics in bacterial translation elongation factors

Bacterial protein synthesis is intricately connected to metabolic rate. One of the ways in which bacteria respond to environmental stress is through posttranslational modifications of translation factors. Translation elongation factor Tu (EF-Tu) is methylated and phosphorylated in response to nutrient starvation upon entering stationary phase, and its phosphorylation is a crucial step in the pathway toward sporulation. We analyze how phosphorylation leads to inactivation of Escherichia coli EF-Tu. We provide structural and biophysical evidence that phosphorylation of EF-Tu at T382 acts as an efficient switch that turns off protein synthesis by decoupling nucleotide binding from the EF-Tu conformational cycle. Direct modifications of the EF-Tu switch I region or modifications in other regions stabilizing the β-hairpin state of switch I result in an effective allosteric trap that restricts the normal dynamics of EF-Tu and enables the evasion of the control exerted by nucleotides on G proteins. These results highlight stabilization of a phosphorylation-induced conformational trap as an essential mechanism for phosphoregulation of bacterial translation and metabolism. We propose that this mechanism may lead to the multisite phosphorylation state observed during dormancy and stationary phase

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

Kidney cancer mortality in Spain: geographic patterns and possible hypotheses

<p>Abstract</p> <p>Background</p> <p>Since the second half of the 1990s, kidney cancer mortality has tended to stabilize and decline in many European countries, due to the decrease in the prevalence of smokers. Nevertheless, incidence of kidney cancer is rising across the sexes in some of these countries, a trend which may possibly reflect the fact that improvements in diagnostic techniques are being outweighed by the increased prevalence of some of this tumor's risk factors. This study sought to: examine the geographic pattern of kidney cancer mortality in Spain; suggest possible hypotheses that would help explain these patterns; and enhance existing knowledge about the large proportion of kidney tumors whose cause remains unknown.</p> <p>Methods</p> <p>Smoothed municipal relative risks (RRs) for kidney cancer mortality were calculated in men and women, using the conditional autoregressive model proposed by Besag, York and Molliè. Maps were plotted depicting smoothed relative risk estimates, and the distribution of the posterior probability of RR>1 by sex.</p> <p>Results</p> <p>Municipal maps displayed a marked geographic pattern, with excess mortality in both sexes, mainly in towns along the Bay of Biscay, including areas of Asturias, the Basque Country and, to a lesser extent, Cantabria. Among women, the geographic pattern was strikingly singular, not in evidence for any other tumors, and marked by excess risk in towns situated in the Salamanca area and Extremaduran Autonomous Region. This difference would lead one to postulate the existence of different exposures of environmental origin in the various regions.</p> <p>Conclusion</p> <p>The reasons for this pattern of distribution are not clear, and it would thus be of interest if the effect of industrial emissions on this disease could be studied. The excess mortality observed among women in towns situated in areas with a high degree of natural radiation could reflect the influence of exposures which derive from the geologic composition of the terrain and then become manifest through the agency of drinking water.</p

THERMAP: a mid-infrared spectro-imager for space missions to small bodies in the inner solar system

We present THERMAP, a mid-infrared (8-16 μm) spectro-imager for space missions to small bodies in the inner solar system, developed in the framework of the MarcoPolo-R asteroid sample return mission. THERMAP is very well suited to characterize the surface thermal environment of a NEO and to map its surface composition. The instrument has two channels, one for imaging and one for spectroscopy: it is both a thermal camera with full 2D imaging capabilities and a slit spectrometer. THERMAP takes advantage of the recent technological developments of uncooled microbolometers detectors, sensitive in the mid-infrared spectral range. THERMAP can acquire thermal images (8-18 μm) of the surface and perform absolute temperature measurements with a precision better than 3.5 K above 200 K. THERMAP can acquire mid-infrared spectra (8-16 μm) of the surface with a spectral resolution Δλ of 0.3 μm. For surface temperatures above 350 K, spectra have a signal-to-noise ratio >60 in the spectral range 9-13 μm where most emission features occur

Reconstruction of the Core and Extended Regulons of Global Transcription Factors

The processes underlying the evolution of regulatory networks are unclear. To address this question, we used a comparative genomics approach that takes advantage of the large number of sequenced bacterial genomes to predict conserved and variable members of transcriptional regulatory networks across phylogenetically related organisms. Specifically, we developed a computational method to predict the conserved regulons of transcription factors across α-proteobacteria. We focused on the CRP/FNR super-family of transcription factors because it contains several well-characterized members, such as FNR, FixK, and DNR. While FNR, FixK, and DNR are each proposed to regulate different aspects of anaerobic metabolism, they are predicted to recognize very similar DNA target sequences, and they occur in various combinations among individual α-proteobacterial species. In this study, the composition of the respective FNR, FixK, or DNR conserved regulons across 87 α-proteobacterial species was predicted by comparing the phylogenetic profiles of the regulators with the profiles of putative target genes. The utility of our predictions was evaluated by experimentally characterizing the FnrL regulon (a FNR-type regulator) in the α-proteobacterium Rhodobacter sphaeroides. Our results show that this approach correctly predicted many regulon members, provided new insights into the biological functions of the respective regulons for these regulators, and suggested models for the evolution of the corresponding transcriptional networks. Our findings also predict that, at least for the FNR-type regulators, there is a core set of target genes conserved across many species. In addition, the members of the so-called extended regulons for the FNR-type regulators vary even among closely related species, possibly reflecting species-specific adaptation to environmental and other factors. The comparative genomics approach we developed is readily applicable to other regulatory networks