Transmission of migration propensity increases genetic divergence between populations

The advent of molecular genetics has brought invaluable information, which is now routinely used by anthropologists in their attempt to reconstruct our demographic past. Since mitochondrial DNA loci are much more similar between populations than are Y-chromosome loci, it is suggested that women had a much higher migration rate than men throughout history. Based on an examination of intergenerational migration patterns in three large demographic databases, we bring this inference into question. In some early Canadian settlements (St. Lawrence Valley and Saguenay), and in the former Krummh?rn region of northwest Germany, men whose fathers were migrants were more likely to migrate, while the migration probability of women was largely independent of that of their mothers. As a result, men's movements were less effective in preventing genetic differentiation between populations than women's movements. In order to account for the impact of transmission, we propose a slight modification of Wright's island model. We also address the relevance of this model at the regional scale, and we discuss the supporting historical and anthropological literature. We conclude that the widespread patrilocal rules of postmarital residence have generated both a higher female migration rate and a patrilineal dependency in the propensity to migrate.     

Matrilineal fertility inheritance detected in hunter-gatherer populations using the imbalance of gene genealogies

Fertility inheritance, a phenomenon in which an individual's number of offspring is positively correlated with his or her number of siblings, is a cultural process that can have a strong impact on genetic diversity. Until now, fertility inheritance has been detected primarily using genealogical databases. In this study, we develop a new method to infer fertility inheritance from genetic data in human populations. The method is based on the reconstruction of the gene genealogy of a sample of sequences from a given population and on the computation of the degree of imbalance in this genealogy. We show indeed that this level of imbalance increases with the level of fertility inheritance, and that other phenomena such as hidden population structure are unlikely to generate a signal of imbalance in the genealogy that would be confounded with fertility inheritance. By applying our method to mtDNA samples from 37 human populations, we show that matrilineal fertility inheritance is more frequent in hunter-gatherer populations than in food-producer populations. One possible explanation for this result is that in hunter-gatherer populations, individuals belonging to large kin networks may benefit from stronger social support and may be more likely to have a large number of offspring.     

Applications of highly sensitive phosphopeptide derivatization methods without the need for organic solvents

Detection and identification of phosphorylated amino acid residues is still one of the most challenging tasks in contemporary protein analysis. Especially serine- and threonine-phosphorylation is very often involved in the regulation of enzyme activities and regulates key functions in cellular processes.     

Morphology Dependence on Surface-Enhanced Raman Scattering Using Gold Nanorod Arrays Consisting of Agglomerated Nanoparticles

Plasmonics - Highly ordered arrays of vertically aligned Au nanorod arrays consisting of agglomerated nanoparticles are fabricated by porous anodic aluminum oxide (AAO) template-assisted...     

Metabolite profiling: development and application of an UHR-QTOF-MS(/MS) method approach for the assessment of metabolic changes in high fat diet fed mice

Introduction

The metabolic alterations accompanying the development of insulin resistance and type 2 diabetes mellitus (T2DM) are complex, not coherently understood and only partially represented by conventional clinical tests like the oral glucose tolerance test. Changes in plasma metabolite concentrations preceding insulin resistance or overt T2DM may help understand the etiology of metabolic disorders and they are potential predictive risk markers.

Objectives

Here, we describe a non-targeted metabolomics platform based on UPLC-UHR-QToF-MS(/MS) for the assessment of plasma non-polar metabolites.

Methods

This method was applied to a longitudinal mouse obesity study comparing mice on control and high fat diet (HFD), respectively. Plasma metabolites were assessed 2, 4, 8 and 16 weeks after initiation of feeding. Multivariate analysis of the metabolite dataset showed clear differentiation of the feeding groups after 8 weeks when the HFD-fed mice exhibited clear signs of insulin resistance.

Results

The discrimination of the groups was due to changes in various metabolic pathways including, among others, glycerophospholipid, sphingolipid and cholesterol metabolism.

Conclusion

From 81 compounds with a p-value lower than 0.05, a total of 19 metabolites could be putatively identified due to their accurate mass, isotope and fragmentation pattern. Thirteen of these observed metabolites are known key metabolites to diabetes or its secondary diseases like diabetic nephropathy and neuropathy (Meiss, Werner, John, Scheja, Herbach, Heeren, Fischer 2015). The compounds putatively identified here may provide valuable starting points for further investigations and developments of clinical diagnostics and prediagnostics for T2DM and related diseases.

     

Connectivity,persistence, and loss of high abundance areas of a recovering marine fish population in the Northwest Atlantic Ocean

In the early 1990s, the Northwest Atlantic Ocean underwent a fisheries‐driven ecosystem shift. Today, the iconic cod (Gadus morhua) remains at low levels, while Atlantic halibut (Hippoglossus hippoglossus) has been increasing since the mid‐2000s, concomitant with increasing interest from the fishing industry. Currently, our knowledge about halibut ecology is limited, and the lack of recovery in other collapsed groundfish populations has highlighted the danger of overfishing local concentrations. Here, we apply a Bayesian hierarchical spatiotemporal approach to model the spatial structure of juvenile Atlantic halibut over 36 years and three fisheries management regimes using three model parameters to characterize the resulting spatiotemporal abundance structure: persistence (similarity of spatial structure over time), connectivity (coherence of temporal pattern over space), and spatial variance (variation across the seascape). Two areas of high juvenile abundance persisted through three decades whereas two in the northeast are now diminished, despite the increased abundance and landings throughout the management units. The persistent areas overlap with full and seasonal area closures, which may act as refuges from fishing. Connectivity was estimated to be 250 km, an order of magnitude less than the distance assumed by the definition of the Canadian management units (~2,000 km). The underlying question of whether there are distinct populations within the southern stock unit cannot be answered with this model, but the smaller ~250 km scale of coherent temporal patterns suggests more complex population structure than previously thought, which should be taken into consideration by fishery management.     

Evolution of the biosynthesis of two hydroxyacetophenones in plants

Acetophenones are phenolic metabolites of plant species. A metabolic route for the biosynthesis and release of 2 defence‐related hydroxyacetophenones in white spruce (Picea glauca) was recently proposed to involve 3 phases: (a) biosynthesis of the acetophenone aglycons catalysed by a currently unknown set of enzymes, (b) formation and accumulation of the corresponding glycosides catalysed by a glucosyltransferase, and (c) release of the aglycons catalysed by a glucosylhydrolase (PgβGLU‐1). We tested if this biosynthetic model is conserved across Pinaceae and land plant species. We assayed and surveyed the literature and sequence databases for possible patterns of the presence of the acetophenone aglycons piceol and pungenol and their glucosides, as well as sequences and expression of Pgβglu‐1 orthologues. In the Pinaceae, the 3 phases of the biosynthetic model are present and differences in expression of Pgβglu‐1 gene orthologues explain some of the interspecific variation in hydroxyacetophenones. The phylogenetic signal in the metabolite phenotypes was low across species of 6 plant divisions. Putative orthologues of PgβGLU‐1 do not form a monophyletic group in species producing hydroxyacetophenones. The biosynthetic model for acetophenones appears to be conserved across Pinaceae, whereas convergent evolution has led to the production of acetophenone glucosides across land plants.     

Diurnal periodicity of assimilate transport shapes resource allocation and whole‐plant carbon balance

Whole‐plant carbon balance comprises diurnal fluctuations of photosynthetic carbon gain and respiratory losses, as well as partitioning of assimilates between phototrophic and heterotrophic organs. Because it is difficult to access, the root system is frequently neglected in growth models, or its metabolism is rated based on generalizations from other organs. Here, whole‐plant cuvettes were used for investigating total‐plant carbon exchange with the environment over full diurnal cycles. Dynamics of primary metabolism and diurnally resolved phloem exudation profiles, as proxy of assimilate transport, were combined to obtain a full picture of resource allocation. This uncovered a strong impact of periodicity of inter‐organ transport on the efficiency of carbon gain. While a sinusoidal fluctuation of the transport rate, with minor diel deflections, minimized respiratory losses in Arabidopsis wild‐type plants, triangular or rectangular patterns of transport, found in mutants defective in either starch or sucrose metabolism, increased root respiration at the end or beginning of the day, respectively. Power spectral density and cross‐correlation analysis revealed that only the rate of starch synthesis was strictly correlated to the rate of net photosynthesis in wild‐type, while in a sucrose‐phosphate synthase mutant (spsa1), this applied also to carboxylate synthesis, serving as an alternative carbon pool. In the starchless mutant of plastidial phospho‐gluco mutase (pgm), none of these rates, but concentrations of sucrose and glucose in the root, followed the pattern of photosynthesis, indicating direct transduction of shoot sugar levels to the root. The results demonstrate that starch metabolism alone is insufficient to buffer diurnal fluctuations of carbon exchange.     

Using gas mixtures of CO,CO2 and H2 as microbial substrates: the do's and don'ts of successful technology transfer from laboratory to production scale

The reduction of CO₂ emissions is a global effort which is not only supported by the society and politicians but also by the industry. Chemical producers worldwide follow the strategic goal to reduce CO₂ emissions by replacing existing fossil‐based production routes with sustainable alternatives. The smart use of CO and CO₂/H₂ mixtures even allows to produce important chemical building blocks consuming the said gases as substrates in carboxydotrophic fermentations with acetogenic bacteria. However, existing industrial infrastructure and market demands impose constraints on microbes, bioprocesses and products that require careful consideration to ensure technical and economic success. The mini review provides scientific and industrial facets finally to enable the successful implementation of gas fermentation technologies in the industrial scale.