Thrombin-like serine proteases in Cerasted venoms (Cerasted cerastes and Cerastes vipera)

Cerastes cerastes and Cerastes vipera snake venoms are rich of thrombin-like, serine-protease polypeptides. Many proteins have been isolated, purified and characterized from these vipers. These proteins act in various way on blood coagulation pathway and platelet function.     

Characterization of a model cyanobacterium Synechocystis sp. PCC 6803 autotrophic growth in a flat‐panel photobioreactor

We characterized the photoautotrophic growth of glucose‐tolerant Synechocystis sp. PCC 6803 in a flat‐panel photobioreactor running on a semicontinuous regime under various lights, temperatures, and influx carbon dioxide concentrations. The maximum reached growth rate was 0.135 h^?1, which corresponds to a doubling time of 5.13 h—a growth speed never reported for Synechocystis before. Saturating red light intensity for the strain was 220–360 μmol(photons) m^?2 s^?1, and we did not observe any photoinhibition up to 660 μmol(photons) m^?2 s^?1. Synechocystis was able to grow under red light only; however, photons of wavelengths 405–585 and 670–700 nm further improved its growth. Optimal growth temperature was 35°C. Below 32°C, the growth rates decreased linearly with temperature coefficient (Q₁₀) 1.70. Semicontinuous cultivation is known to be efficient for growth characterization and optimization. However, the assumption of correct growth rates calculation—culture exponential growth—is often not fulfilled. The semicontinuous setup in this study was operated as a turbidostat. Accurate online OD measurements with high time‐resolution allowed fast and reliable growth rates determination. Repeating diluting frequencies (up to 18 dilutions per day) were essential for rapid growth stability evaluation. The presented setup provides improvement to previously published semicontinuous characterization strategies by decreasing experimental time requirements and maintaining the culture in exponential growth phase throughout the entire characterization procedure.     

Risk Factors for Sporadic Non-Pregnancy Associated Listeriosis in Germany—Immunocompromised Patients and Frequently Consumed Ready-To-Eat Products

Non-pregnancy associated (N-PA) listeriosis, caused by Listeria monocytogenes, is a rare but severe disease, and is predominantly food-borne. Most cases appear sporadic and their infection vehicle remains unknown. Incidence has increased since 2008 in Germany. We aimed to identify underlying conditions and foods associated with sporadic N-PA listeriosis in Germany. We performed a nationwide case-control study from March 2012-December 2013. Cases were sporadic N-PA listeriosis patients notified to public health. Control subjects were age (40–65 years, 66–75 years, ≥76 years) frequency-matched persons from a nationwide random telephone sample. A structured questionnaire collected information on underlying diseases, therapies and >60 food items. We conducted multivariable logistic regression analysis, adjusting for host factors identified by causal diagram theory, and calculated population attributable fractions. We enrolled 109 cases and 1982 controls. Cases’ median age was 69 years, 55% were male, 44% received immunosuppressive therapy within 3 months prior to illness onset; a further 28% had at least one immunocompromising disease. In multivariable analysis, immunosuppressive therapy (OR 8.8, 95%CI 4.9–15.6), immunocompromising disease (OR 2.7; 95%CI 1.4–5.2), gastric acid suppression (OR 3.0; 95%CI 1.4–6.3), the consumption of cold cooked sausages (OR 2.6; 95%CI 1.6–4.4), the preferred consumption of packaged cheese (OR 2.1; 95%CI 1.3–3.5) and pre-sliced cheese (OR 2.2; 95%CI 1.3–3.7) were significantly associated with N-PA listeriosis. These foods accounted for 59% of all cases. Typical high risk foods, e.g. cold seafood, certain types of cheeses, tended to be negatively associated with disease. In conclusion, immunosuppressive therapy and frequently consumed ready-to-eat foods are the main risk factors for sporadic N-PA listeriosis in Germany. To reduce their risk, immunocompromised persons should consume the identified foods well before the ‘use-by’ date. The microbiological criteria for Listeria monocytogenes in ready-to-eat foods may insufficiently protect persons who are markedly immunocompromised.     

Spectral information as an orientation cue in dung beetles

During the day, a non-uniform distribution of long and short wavelength light generates a colour gradient across the sky. This gradient could be used as a compass cue, particularly by animals such as dung beetles that rely primarily on celestial cues for orientation. Here, we tested if dung beetles can use spectral cues for orientation by presenting them with monochromatic (green and UV) light spots in an indoor arena. Beetles kept their original bearing when presented with a single light cue, green or UV, or when presented with both light cues set 180° apart. When either the UV or the green light was turned off after the beetles had set their bearing in the presence of both cues, they were still able to maintain their original bearing to the remaining light. However, if the beetles were presented with two identical green light spots set 180° apart, their ability to maintain their original bearing was impaired. In summary, our data show that ball-rolling beetles could potentially use the celestial chromatic gradient as a reference for orientation.     

In Depth Characterization of Repetitive DNA in 23 Plant Genomes Reveals Sources of Genome Size Variation in the Legume Tribe Fabeae

The differential accumulation and elimination of repetitive DNA are key drivers of genome size variation in flowering plants, yet there have been few studies which have analysed how different types of repeats in related species contribute to genome size evolution within a phylogenetic context. This question is addressed here by conducting large-scale comparative analysis of repeats in 23 species from four genera of the monophyletic legume tribe Fabeae, representing a 7.6-fold variation in genome size. Phylogenetic analysis and genome size reconstruction revealed that this diversity arose from genome size expansions and contractions in different lineages during the evolution of Fabeae. Employing a combination of low-pass genome sequencing with novel bioinformatic approaches resulted in identification and quantification of repeats making up 55–83% of the investigated genomes. In turn, this enabled an analysis of how each major repeat type contributed to the genome size variation encountered. Differential accumulation of repetitive DNA was found to account for 85% of the genome size differences between the species, and most (57%) of this variation was found to be driven by a single lineage of Ty3/gypsy LTR-retrotransposons, the Ogre elements. Although the amounts of several other lineages of LTR-retrotransposons and the total amount of satellite DNA were also positively correlated with genome size, their contributions to genome size variation were much smaller (up to 6%). Repeat analysis within a phylogenetic framework also revealed profound differences in the extent of sequence conservation between different repeat types across Fabeae. In addition to these findings, the study has provided a proof of concept for the approach combining recent developments in sequencing and bioinformatics to perform comparative analyses of repetitive DNAs in a large number of non-model species without the need to assemble their genomes.     

Deoxyribonucleases (DNases) in the cortex and endosome from the marine sponge <Emphasis Type="Italic">Tethya aurantium</Emphasis>

The presence and activity of deoxyribonucleases in the cortex and endosome sections from a sponge, the sea orange Tethya aurantium, were investigated. The maximal enzyme activity in sponge homogenate was detected at pH 4.27, pH 7.0 and pH 8.5–8.75. Among different specimens, several distinct patterns of neutral DNase isozymes were observed in the cortex section. In each investigated specimen the highest neutral DNase activity belonged to high molecular weight proteins (up to75 kDa). The acid DNases showed a low level of enzyme activity. In the endosome section the acid DNase activity was up to ten times higher than in the cortex and the presence of DNase II-like protein was detected. Neutral DNase, which expressed the highest enzyme activity in all the investigated specimens, has a molecular weight of 20 kDa and belongs to the DNase I-like family. The results indicate that the activity of neutral and acid DNases is related to sponge sections and their biological functions. The cortex, as the sponge section that communicates with the environment, expresses high interindividual variability and heterogeneity of neutral DNases, while the endosome section, where the intracellular digestion is localized, is a site of high acid DNase activity.     

Cervical collagen and biomechanical strength in non-pregnant women with a history of cervical insufficiency

Background  

It has been suggested that cervical insufficiency (CI) is characterized by a "muscular cervix" with low collagen and high smooth muscle concentrations also in the non-pregnant state. Therefore, the aim of this study was to investigate the biomechanical properties, collagen concentration, smooth muscle cell density, and collagen fiber orientation in cervical biopsies from non-pregnant women with a history of CI.     

Secretion of antidiuretic hormone and renal function during the awakening of Jaculus orientalis from hibernation

Chemical analysis of kidney tissue from jerboa (Jaculus orientalis) during hibernation shows that the cortico-papillary gradient of Na+ ions is strongly reduced, whereas that of urea is completely suppressed. During the spontaneous rise in body temperature which occurs as the animal comes out of hibernation, the accumulation of Na+ in the papilla then in the medullary zones begins to increase from 25-30 degrees C body temperature, before the appearance of a urea gradient. This confirms the hypothesis that urea accumulation in the kidney medulla is coupled to active transport of sodium. This active transport may be partially dependent upon circulating ADH, circulating levels of which increase with increasing body temperature. Glomerular filtration in normothermic jaculus orientalis is 696 +/- 155 microliter . min-1 and urinary flow is relatively low in this desert species at 1.12 +/- 0.18 microliter . min-1. During hibernation at a body temperature between 7 and 8 degrees C glomerular filtration and urinary flow are not measurable. Glomerular filtration appears (51 microliter . min-1 at 26 degrees C) and increases at a temperature range where systemic blood pressure has already attained a normal level. This indicates that the reestablishment of glomerular filtration may be linked to intra-renal vasomotor events as is suggested by measurement of plasma renin activity during the coming out of hibernation.     

Incidences de la restriction calorique et du Nickel sur l’aromatase testiculaire du rat

This study was designed to determine whether intermittent fasting induces malnutrition that, according to many authors, accentuates the cytotoxic effects of environmental pollutants, or caloric restriction that reduces these effects. Ninety six male Wistar rats (180g) were divided into two groups: one group was fed daily (N) and the other group was fed every second day (J) for one month. At the end of one month, each group was then divided into two subgroups, one subgroup received an injection of 0.9% NaCI (groups NO and JO), the other subgroup received an injection of 4 mg/kg NiCI^b2 (groups NNi and JNi). Intermittent fasting was continued in parallel to treatment for 1, 3, 5 and 10 days. Under these experimental conditions, nickel increased testicular aromatase activity and altered total RNA, while no alteration of these biomarkers was observed with intermittent fasting. The combination of these two factors, nickel and intermittent fasting, did not amplify these effects. In contrast, protection of RNA by intermittent fasting was observed, especially overexpression of aromatase mRNA.