CRISPR-TSKO : a technique for efficient mutagenesis in specific cell types, tissues, or organs in Arabidopsis

Detailed functional analyses of many fundamentally important plant genes via conventional loss-of-function approaches are impeded by the severe pleiotropic phenotypes resulting from these losses. In particular, mutations in genes that are required for basic cellular functions and/or reproduction often interfere with the generation of homozygous mutant plants, precluding further functional studies. To overcome this limitation, we devised a clustered regularly interspaced short palindromic repeats (CRISPR)-based tissue-specific knockout system, CRISPR-TSKO, enabling the generation of somatic mutations in particular plant cell types, tissues, and organs. In Arabidopsis (Arabidopsis thaliana), CRISPR-TSKO mutations in essential genes caused well-defined, localized phenotypes in the root cap, stomatal lineage, or entire lateral roots. The modular cloning system developed in this study allows for the efficient selection, identification, and functional analysis of mutant lines directly in the first transgenic generation. The efficacy of CRISPR-TSKO opens avenues for discovering and analyzing gene functions in the spatial and temporal contexts of plant life while avoiding the pleiotropic effects of system-wide losses of gene function

Permafrost Thaw and Liberation of Inorganic Nitrogen in Eastern Siberia

The currently observed climate warming will lead to widespread degradation of near-surface permafrost, which may release substantial amounts of inorganic nitrogen (N) into arctic ecosystems. We studied 11 soil profiles at three different sites in arctic eastern Siberia to assess the amount of inorganic N stored in arctic permafrost soils. We modelled the potential thickening of the active layer for these sites using the CryoGrid2 permafrost model and representative concentration pathways (RCPs) 4.5 (a stabilisation scenario) and 8.5 (a business as usual emission scenario, with increasing carbon emissions). The modelled increases in active-layer thickness (ALT) were used to estimate potential annual liberation of inorganic N from permafrost soils during the course of climate change. We observed significant stores of inorganic ammonium in permafrost, up to 40-fold higher than in the active layer. The modelled increase in ALT under the RCP8.5 scenario can result in substantial liberation of N, reaching values up to the order of magnitude of annual fixation of atmospheric N in arctic soils. However, the thaw-induced liberation of N represents only a small flux in comparison with the overall ecosystem N cycling

Literary-theoretical Transformations of Social Models

This study investigates transformations of classical antiquity oikonomia and chrematistics from the Middle Ages to the present-day.From an ancient- historical, philosophical, literary and cultural-science perspective, it reconstructs exemplary acquisitions and reinterpretations of economic knowledge. The study argues that the modern economy has benefited from transformation relationships with the oikonomia of classical antiquity, which exhibit no unambiguously economic, efficient and profit-maximising character. For this reason, in addition to actual historical aspects, our interest also includes issues relating to the poetology of economic knowledge, the metaphorology and scenaristics of the house, the theoretical, narrative and literary representation economies and the promotion of ‘economy’ to an ordering category per se

Long-term monitoring (1953–2019) of geomorphologically active sections of Little Ice Age lateral moraines in the context of changing meteorological conditions

We show a long-term erosion monitoring of several geomorphologically active gully systems on Little Ice Age lateral moraines in the European Central–Eastern Alps, covering a total time period from 1953 to 2019 and including several survey periods in order to identify corresponding morphodynamic trends. For the implementation, DEM (digital elevation model) of Differences (DoDs) were calculated, based on multitemporal high-resolution digital elevation models from historical aerial images (generated by structure from motion photogrammetry with multi-view stereo) and light detection and ranging from airborne platforms. Two approaches were implemented to achieve the corresponding objectives. First, by calculating linear regression models using the accumulated sediment yield and the corresponding catchment area (on a log–log scale), the range of the variability in the spatial distribution of erosion values within the sites. Second, we use volume calculations to determine the total and the mean sediment yield (as well as erosion rates) of the entire sites. Subsequently, both the sites and the different time periods of both approaches are compared. Based on the slopes of the calculated regression lines, it can be shown that the highest variability in the sediment yield at the sites occurs in the first time period (mainly 1950s to 1970s). This can be attributed to the fact that within some sites the sediment yield per square metre increases clearly more strongly (regression lines with slopes up to 1.5). In contrast, in the later time periods (1970s to mid-2000s and mid-2000s to 2017/2019), there is generally a decrease in 10 out of 12 cases (regression lines with slopes around 1). However, even at sites with an increase in the variability in the sediment yield over time, the earlier high variabilities are no longer reached. This means that the spatial pattern of erosion in the gully heads changes over time as it becomes more uniform. Furthermore, using sediment volume calculations and corresponding erosion rates, we show a generally decreasing trend in geomorphic activity (amount of sediment yield) between the different time periods in 10 out of 12 sites, while 2 sites show an opposite trend, where morphodynamics increase and remain at the same level. Finally, we summarise the results of long-term changes in the morphodynamics of geomorphologically active areas on lateral moraines by presenting the “sediment activity concept”, which, in contrast to theoretical models, is based on actually calculated erosion. The level of geomorphic activity depends strongly on the characteristics of the sites, such as size, slope length, and slope gradient, some of which are associated with deeply incised gullies. It is noticeable that especially areas with influence of dead ice over decades in the lower slope area show high geomorphic activity. Furthermore, we show that system internal factors, as well as the general paraglacial adjustment process, have a greater influence on long-term morphodynamics than changing external weather and climate conditions, which, however, had a slight impact mainly in the last, i.e. most recent, time period (mid-2000s to 2017/2019) and may have led to an increase in erosion at the sites

Permafrost thaw and release of inorganic nitrogen from polygonal tundra soils in eastern Siberia

The currently observed climate warming will lead to substantial permafrost degradation and mobilization of formerly freeze-locked matter. Based on recent findings, we assume that there are substantial stocks of inorganic nitrogen (N) within the perennially frozen ground of arctic ecosystems. We studied eleven soil profiles down to one meter depth below surface at three different sites in arctic eastern Siberia, covering polygonal tundra and river floodplains, to assess the amount of inorganic N stores in arctic permafrost-affected soils. Furthermore, we modeled the potential thickening of the seasonally unfrozen uppermost soil (active) layer for these sites, using the CryoGrid2 permafrost model and representation concentration pathway (RCP) 4.5 and 8.5 scenarios. The first scenario, RCP4.5, is a stabilization pathway that reaches plateau atmospheric carbon concentrations early in the 21st century; the second, RCP8.5, is a business as usual emission scenario with increasing carbon emissions. The modeled increases in active layer thickness (ALT) were used to estimate potential annual N mobilization from permafrost-affected soils in the course of climate-induced active-layer deepening. We observed significant stores of inorganic ammonium in the perennially frozen ground of all investigated soils, up to 40-fold higher than in the active layer. The modeled ALT increase until 2100 under the RCP8.5 scenario was between 19 ± 3 cm and 35 ± 6 cm, depending on the location. Under the RCP4.5 scenario, the ALT remained stable in all investigated soils. Our estimated mean annual N release under the RCP8.5 scenario is between 8 ± 3 mg m−2 and 81 ± 14 mg m−2 for the different locations, which reaches values up to the order of magnitude of annual fixation of atmospheric N in arctic soils. However, the thawing induced release of N represents only a small flux in comparison with the overall ecosystem N cycling

Exploring the shell-based taxonomy of the Sri Lankan land snail Corilla H. and A. Adams, 1855 (Pulmonata: Corillidae) using mitochondrial DNA

The land-snail genus Corilla is endemic to Sri Lanka and India’s Western Ghats. The ten extant Sri Lankan species belong to two distinct shell forms that are associated respectively with lowland and montane rainforest. We here present the first molecular phylogenetic analysis for Corilla. Our dataset includes nine nominal Sri Lankan species and is based on three mitochondrial genes (CO1, ND1 and 16S). Although the deeper nodes in the trees are not fully resolved, the results do suggest speciation in Corilla has involved repeated, ecologically-driven convergence in shell form. The mtDNA data agree with the current shell-based taxonomy for C. adamsi, C. beddomeae, C. carabinata, C. humberti and C. colletti, consistently supporting the first four as monophyletic, and supporting the last also as monophyletic in nearly all analyses. Corilla adamsi, C. beddomeae and C. colletti may each contain at least one additional, previously undescribed species. The relationship between northern and eastern C. odontophora couldn’t be reliably resolved, but our results suggest that they are distinct species and that there is further species-level or intraspecific (geographical) differentiation within eastern C. odontophora. The current, morphologically-defined species limits of the three remaining nominal species, C. gudei, C. erronea and C. fryae, are inconsistent with the mtDNA sequence data. Northern and southern C. gudei appear to be distinct species: the sister taxon of southern C. gudei is C. humberti, and most analyses showed that the sister taxon of northern C. gudei is the lowland C. carabinata. Corilla erronea and C. fryae constitute a well supported clade in which both nominal species are paraphyletic. While most intra-clade CO1 p-distances are moderate to relatively large, the phylogenetic structuring within the clade does not seem to correspond to any obvious morphological, elevational or geographical patterns. These results are difficult to interpret, and further detailed study is needed before the taxonomic status of C. erronea and C. fryae can be resolved

Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA

Correlations between charged particles in deep inelastic ep scattering have been studied in the Breit frame with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in terms of the angular separation between current-region particles within a cone centred around the virtual photon axis. Long-range correlations between the current and target regions have also been measured. The data support predictions for the scaling behaviour of the angular correlations at high Q2 and for anti-correlations between the current and target regions over a large range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations and Monte Carlo models correctly describe the trends of the data at high Q2, but show quantitative discrepancies. The data show differences between the correlations in deep inelastic scattering and e+e- annihilation.Comment: 26 pages including 10 figures (submitted to Eur. J. Phys. C

A highly polymorphic insertion in the Y-chromosome amelogenin gene can be used for evolutionary biology, population genetics and sexing in Cetacea and Artiodactyla

<p>Abstract</p> <p>Background</p> <p>The early radiation of the <it>Cetartiodactyla </it>is complex, and unambiguous molecular characters are needed to clarify the positions of hippotamuses, camels and pigs relative to the remaining taxa (<it>Cetacea </it>and <it>Ruminantia</it>). There is also a need for informative genealogic markers for Y-chromosome population genetics as well as a sexing method applicable to all species from this group. We therefore studied the sequence variation of a partial sequence of the evolutionary conserved amelogenin gene to assess its potential use in each of these fields.</p> <p>Results and discussion</p> <p>We report a large interstitial insertion in the Y amelogenin locus in most of the <it>Cetartiodactyla </it>lineages (cetaceans and ruminants). This sex-linked size polymorphism is the result of a 460–465 bp inserted element in intron 4 of the amelogenin gene of Ruminants and Cetaceans. Therefore, this polymorphism can easily be used in a sexing assay for these species.</p> <p>When taking into account this shared character in addition to nucleotide sequence, gene genealogy follows sex-chromosome divergence in <it>Cetartiodactyla </it>whereas it is more congruent with zoological history when ignoring these characters. This could be related to a loss of homology between chromosomal copies given the old age of the insertion.</p> <p>The 1 kbp <it>Amel-Y </it>amplified fragment is also characterized by high nucleotide diversity (64 polymorphic sites spanning over 1 kbp in seven haplotypes) which is greater than for other Y-chromosome sequence markers studied so far but less than the mitochondrial control region.</p> <p>Conclusion</p> <p>The gender-dependent polymorphism we have identified is relevant not only for phylogenic inference within the <it>Cetartiodactyla </it>but also for Y-chromosome based population genetics and gender determination in cetaceans and ruminants. One single protocol can therefore be used for studies in population and evolutionary genetics, reproductive biotechnologies, and forensic science.</p

Inhibition of phosphodiesterase‐4 promotes oligodendrocyte precursor cell differentiation and enhances CNS

The increasing effectiveness of new disease-modifying drugs that suppress disease activity in multiple sclerosis has opened up opportunities for regenerative medicines that enhance remyelination and potentially slow disease progression. Although several new targets for therapeutic enhancement of remyelination have emerged, few lend themselves readily to conventional drug development. Here, we used transcription profiling to identify mitogen-activated protein kinase (Mapk) signalling as an important regulator involved in the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes. We show in tissue culture that activation of Mapk signalling by elevation of intracellular levels of cyclic adenosine monophosphate (cAMP) using administration of either dibutyryl-cAMP or inhibitors of the cAMP-hydrolysing enzyme phosphodiesterase-4 (Pde4) enhances OPC differentiation. Finally, we demonstrate that systemic delivery of a Pde4 inhibitor leads to enhanced differentiation of OPCs within focal areas of toxin-induced demyelination and a consequent acceleration of remyelination. These data reveal a novel approach to therapeutic enhancement of remyelination amenable to pharmacological intervention and hence with significant potential for translation