Diversity of Entamoeba spp. in African great apes and humans: an insight from Illumina MiSeq high-throughput sequencing

Understanding the complex Entamoeba communities in the mammalian intestine has been, to date, complicated by the lack of a suitable approach for molecular detection of multiple variants co-occurring in mixed infections. Here, we report on the application of a high throughput sequencing approach based on partial 18S rDNA using the Illumina MiSeq platform. We describe, to our knowledge, for the first time, the Entamoeba communities in humans, free-ranging western lowland gorillas and central chimpanzees living in the Dja Faunal Reserve in Cameroon. We detected 36 Entamoeba haplotypes belonging to six haplotype clusters, containing haplotypes possessing high and low host specificity. Most of the detected haplotypes belonged to commensal Entamoeba, however, the pathogenic species (Entamoeba histolytica and Entamoeba nuttalli) were also detected. We observed that some Entamoeba haplotypes are shared between humans and other hosts, indicating their zoonotic potential. The findings are important not only for understanding the epidemiology of amoebiasis in humans in rural African localities, but also in the context of wild great ape conservation.     

Production of 1,2‐propanediol in photoautotrophic Synechocystis is linked to glycogen turn‐over

We utilized a photoautotrophic organism to synthesize 1,2‐propanediol from carbon dioxide and water fueled by light. A synthetic pathway comprising mgsA (methylglyoxal synthase), yqhD (aldehyde reductase), and adh (alcohol dehydrogenase) was inserted into Synechocystis sp. PCC6803 to convert dihydroxyacetone phosphate to methylglyoxal, which is subsequently reduced to acetol and then to 1,2‐propanediol. 1,2‐propanediol could be successfully produced by Synechocystis, at an approximate rate of 55 μmol h^?1 g_CDW^?1. Surprisingly, maximal productivity was observed in the stationary phase. The production of 1,2‐propanediol was clearly coupled to the turn‐over of intracellular glycogen. Upon depletion of the glycogen pool, product formation stopped. Reducing the carbon flux to glycogen significantly decreased final product titers. Optimization of cultivation conditions allowed final product titers of almost 1 g L^?1 (12 mM), which belongs to the highest values published so far for photoautotrophic production of this compound.

     

Opioid and Notch signaling pathways are reciprocally regulated through miR- 29a and miR-212 expression

Background

The abuse of opioids, such as morphine and phentanyl or other drugs as heroin is a social and health problem that affects an increasing number of people each year. The activation of the mu opioid receptor triggers several molecular changes that alter the expression of diverse genes, including miRNAs. The dysregulation of these molecules could explain some of the developmental alterations that are induced after drug intake. In addition, the Notch signaling cascade has also been related to alterations on these processes.

Effects of the Serotonin 5-HT<Subscript>1A</Subscript> Receptor Biased Agonists,F13714 and F15599, on Striatal Neurotransmitter Levels Following <Emphasis Type="SmallCaps">l</Emphasis>-DOPA Administration in Hemi-Parkinsonian Rats

Peak-dose dyskinesia is associated with the dramatic increase in striatal dopamine levels that follows l-DOPA administration. The ‘false neurotransmitter’ hypothesis postulates that the latter is likely due to an aberrant processing of l-DOPA by serotonergic neurons. In keeping with this hypothesis, two highly selective ‘biased agonists’ of 5-HT_1A receptors—namely F13714 and F15599 (NLX-101)—were recently shown to exhibit exceptionally potent anti-dyskinetic activity without impairing l-DOPA therapeutic properties despite their differential targeting of 5-HT_1A receptor sub-populations. In this study, we investigated whether these two compounds dampened peak l-DOPA-induced dopamine microdialysate levels in the striatum of hemi-parkinsonian rats. Acute administration of either F13714 (0.04 and 0.16 mg/kg i.p.) or F15599 (0.16 and 0.64 mg/kg, i.p.) blunted l-DOPA (2 mg/kg)-induced increases in dopamine microdialysate levels in the denervated striatum (following unilateral injection of 6-OHDA into the medial forebrain bundle). No significant changes were observed on the intact side of the brain. Concurrently, both drugs profoundly reduced striatal serotonin levels on both sides of the brain. In addition, F13714 and F15599, in the presence of l-DOPA, produced a dose-dependent increase in glutamate levels, but this effect was restricted to later time points. These finding support the interpretation that F13714 and F15599 mediate their anti-dyskinetic effects by blunting of the peak in dopamine levels via activation of somatodendritic serotonin 5-HT_1A receptors and the consequent inhibition of serotonergic neurons. This study adds to the growing body of evidence supporting the development of a potent 5-HT_1A receptor agonist for treatment of peak-dose dyskinesia.     

Associations between chronotype,sleep disturbances and seasonality with fatigue and inflammatory bowel disease symptoms

Growing number of studies suggests link between circadian rhythms and inflammatory bowel diseases (IBD) manifestation. We hypothesize that: 1) IBD are associated with increased eveningness and sleep disturbances; 2) eveningness and sleep disturbances are related to more severe IBD symptoms. In total, 129 participants were enrolled to this study, divided into three groups: 34 Crohn’s disease (CD) patients, 38 ulcerative colitis (UC) patients and 57 healthy controls (HC) group. They all fulfilled a questionnaire, consisting of the Composite Scale of Morningness (CSM), Seasonal Pattern Assessment Questionnaire (SPAQ), Pittsburgh Sleep Quality Index, Inflammatory Bowel Disease Questionnaire (IBDQ) and Multidimensional Fatigue Inventory (MFI). Multiple regression models controlled for age and sex revealed that in CD group higher eveningness measured with CSM was associated with higher general fatigue, physical fatigue, mental fatigue and reduced motivation measured by MFI. Lower CSM morning affect is associated with greater general fatigue, physical fatigue and more reduced activity. Greater seasonality scores are associated with increased physical fatigue and more reduced activity and motivation. Lower sleep quality measured with PSQI is associated with higher physical fatigue and more reduced activity. Correlational analysis revealed that higher seasonality and lower sleep quality are associated with increased systemic and bowel symptoms and decreased emotional and social functions measured with IBDQ. In UC group, eveningness is associated with greater general fatigue, physical fatigue and more reduced activity. Higher CSM morning affect is associated with decreased general fatigue, physical fatigue and less reduced activity. Higher CSM circadian preference scores are associated with decreased general and physical fatigue, and less reduced activity. Increased seasonality is associated with more physical fatigue. Lower sleep quality is associated with greater general and physical fatigue. To our best knowledge this is the first study evaluating associations between chronotype and sleep disturbances with IBD symptoms. We have found that chronotype preferences, whose role in IBD has been until now overlooked, may be one of the important factors contributing to fatigue in this clinical group.     

Trends in sightings and population structure of white sharks, <Emphasis Type="Italic">Carcharodon carcharias,</Emphasis> at Seal Island,False Bay,South Africa,and the emigration of subadult female sharks approaching maturity

A long-term sightings and photographic identification (photo-ID) database documented the inter-annual and monthly trends in white shark (Carcharodon carcharias) sightings, sex ratios and life-history stages at Seal Island, False Bay, South Africa, over the period 2004–2012. A total of 1105 sightings were recorded during 171 scientific surveys incorporating 577 h of observation (annual mean 64.10 h, range 23.71–178.69 h). The mean annual sighting rate was 1.87 (range 0.90–3.19) sharks per hour and sighting rates declined over the nine-year study period. It is unknown whether the decline resulted from an actual population decline, or was due to changes in shark distribution or environmental conditions, but it highlights the need for ongoing monitoring at this site. The overall sex ratio was 1.0: 1.0: 2.3 for male: female: unsexed sharks, respectively. Of the 1105 sightings, 39% (n = 433) were photo-ID’d, representing 303 individual sharks (112: 111: 80, male: female: unsexed) and 130 resightings. Of the 303 photo-ID’d sharks, 71% were sighted in a single year only, indicative of transient behaviour. Of the 29% of sharks that were resighted in more than one year, 65% were resighted in the following year, indicating site fidelity to Seal Island, whereas 35% skipped one or more years between encounters, indicative of a temporary absence. The majority (60%) of the photo-ID’d sharks were immature, 32% were subadult and only 8% were mature. No young-of-the-year sharks and few adults were recorded, indicating that Seal Island is not an adult aggregation site, nor a pupping or nursery area, but rather is best described as a seasonal feeding ground. Large females were rarely resighted again after they approached length-at-maturity (≥450 cm TL), whereas some adult males were recorded consistently across years. The emigration of subadult female sharks approaching maturity from Seal Island, combined with the small number of mature sharks of both sexes reported from any South African location, indicate that adult aggregation sites, and thus areas of reproductive importance, still remain unknown.     

The cholangiocyte primary cilium in health and disease

Cholangiocytes, like most cells, express primary cilia extending from their membranes. These organelles function as antennae which detect stimuli from bile and transmit the information into cells regulating several signaling pathways involved in secretion, proliferation and apoptosis. The ability of primary cilia to detect different signals is provided by ciliary associated proteins which are expressed in its membrane. Defects in the structure and/or function of these organelles lead to cholangiociliopathies that result in cholangiocyte hyperproliferation, altered fluid secretion and absorption. Since primary cilia dysfunction has been observed in several epithelial tumors, including cholangiocarcinoma (CCA), primary cilia have been proposed as tumor suppressor organelles. In addition, the loss of cilia is associated with dysregulation of several molecular pathways resulting in CCA development and progression. Thus, restoration of the primary cilia may be a potential therapeutic approach for several ciliopathies and CCA.     

Patterns and drivers of aquatic invertebrate diversity across an arid biome

Managing and restoring faunal diversity across large areas requires an understanding of the roles of connectivity and dispersal in driving community patterns. We sought to determine the influence of connectivity, water regime, water source, geographical location, and dispersal traits on patterns of aquatic invertebrate diversity across a continent‐wide arid biome. We compiled data on freshwater invertebrate assemblages from sites spanning the breadth of arid Australia. Univariate analyses (analysis of variance and rarefaction) revealed that alpha and gamma diversity across sites decreased as latitude increased. Multivariate analyses (ordination and analysis of similarity) revealed that community composition had considerable fidelity to geographic regions. Hydrological connectivity was strongly associated with riverine community composition although water rarely flowed (often less than annually). Hydrologically isolated sites (springs and rockholes) supported communities that were markedly dissimilar to hydrologically connected sites, and to each other. We investigated the influence of dispersal on diversity patterns by examining distance decay relationships for each of four dispersal trait groups (obligate aquatic and passive, weak, and strong aerial dispersers) on the basis of geodesic (shortest path) distances between pairs of sites and Mantel tests. We did not detect clear differences between dispersal traits and distance decay relationships at the continental scale, even for the two groups with the lowest dispersal ability (obligate aquatics and passive dispersers). Our results suggest that the loss of hydrological connectivity from water developments in arid lands (for example, the impoundment of intermittent rivers) is likely to affect macroinvertebrates. However, the exact flow mechanisms underlying such changes remain to be determined.