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It remains largely unclear how thymocytes translate relative differences in T cell receptor (TCR) signal strength into distinct developmental programs that drive the cell fate decisions towards conventional (Tconv) or regulatory T cells (Treg). Following TCR activation, intracellular calcium (Ca2+) is the most important second messenger, for which the potassium channel K2P18.1 is a relevant regulator. Here, we identify K2P18.1 as a central translator of the TCR signal into the thymus-derived Treg (tTreg) selection process. TCR signal was coupled to NF-κB-mediated K2P18.1 upregulation in tTreg progenitors. K2P18.1 provided the driving force for sustained Ca2+ influx that facilitated NF-κB- and NFAT-dependent expression of FoxP3, the master transcription factor for Treg development and function. Loss of K2P18.1 ion-current function induced a mild lymphoproliferative phenotype in mice, with reduced Treg numbers that led to aggravated experimental autoimmune encephalomyelitis, while a gain-of-function mutation in K2P18.1 resulted in increased Treg numbers in mice. Our findings in human thymus, recent thymic emigrants and multiple sclerosis patients with a dominant-negative missense K2P18.1 variant that is associated with poor clinical outcomes indicate that K2P18.1 also plays a role in human Treg development. Pharmacological modulation of K2P18.1 specifically modulated Treg numbers in vitro and in vivo. Finally, we identified nitroxoline as a K2P18.1 activator that led to rapid and reversible Treg increase in patients with urinary tract infections. Conclusively, our findings reveal how K2P18.1 translates TCR signals into thymic T cell fate decisions and Treg development, and provide a basis for the therapeutic utilization of Treg in several human disorders.

The cleptoparasitic beeAmmobates (Ammobates) roggeveldin. sp. is described from a female specimen collected in western South Africa. This is only the second species of the genus recorded from sub-Saharan Africa. Une nouvelle espèce d’abeille d’Afrique subsaharienne du genreAmmobatesLatreille, 1809 (Hymenoptera : Apidae) Une nouvelle espèce du genre cleptoparasiteAmmobates,Ammobates (Ammobates) roggeveldin. sp., est décrite à partir d’un spécimen femelle collecté en Afrique du Sud occidentale. C’est seulement la deuxième espèce de ce genre rapportée pour l’Afrique subsaharienne.&nbsp

At low temperature many insects lose extracellular ion homeostasis and the capacity to mitigate homeostatic imbalance determines their cold tolerance. Extracellular homeostasis is ensured by the osmoregulatory organs and recent research has emphasized key roles for the Malpighian tubules and hindgut in modulating insect cold tolerance. Here, we review the effects of low temperature on transport capacity of osmoregulatory organs and outline physiological processes leading from cold exposure to disruption of ion homeostasis and cold-injury in insects. We show how cold adaptation and cold acclimation are associated with physiological modifications to transport capacity in Malpighian tubules and hindgut. These responses mitigate loss of homeostasis and we highlight how further study of molecular and cellular mechanisms are critical to fully appreciate the adaptations that facilitate insect cold tolerance.

Oligodendroglial progenitor cells (OPC) are highly proliferative and migratory bipolar cells, which differentiate into complex myelin forming and axon ensheathing mature oligodendrocytes during myelination. Recent studies indicate that the oligodendroglial cell population is heterogeneous on transcriptional and functional level depending on the location in the CNS. Here, we compared intrinsic properties of OPC from spinal cord and brain on functional and transcriptional level. Spinal cord OPC demonstrated increased migration as well as differentiation capacity. Moreover, transcriptome analysis revealed differential expression of several genes between both OPC populations. In spinal cord OPC we confirmed upregulation of SKAP2, a cytoplasmatic adaptor protein known for its implication in cytoskeletal remodelling and migration in other cell types. Recent findings suggest that actin dynamics determine not only oligodendroglial migration, but also differentiation: Whereas actin polymerization is important for process extension, actin destabilization and depolymerization is required for myelin sheath formation. Downregulation or complete lack of SKAP2 in OPC resulted in reduced migration and impaired morphological maturation in oligodendrocytes. In contrast, overexpression of SKAP2 as well as constitutively active SKAP2 increased OPC migration suggesting that SKAP2 function is dependent on activation by phosphorylation. Furthermore, lack of SKAP2 enhanced the positive effect on OPC migration after integrin activation suggesting that SKAP2 acts as modulator of integrin dependent migration. In summary, we demonstrate the presence of intrinsic differences between spinal cord and brain OPC and identified SKAP2 as a new regulator of oligodendroglial migration and sheath formation.Significance statementOPC play an important role in many still incurable diseases, such as multiple sclerosis, leukodystrophies or neurodegenerative diseases. Their heterogeneity in different CNS regions has recently been identified. Here, we observed increased migration and differentiation capabilities of OPC isolated from the spinal cord compared to brain OPC and confirmed differences in the transcriptome between these two cell populations. Furthermore, we identified SKAP2 as potential modulator of actin dynamics in oligodendrocytes. Whereas knockdown or lack of SKAP2 impairs migration and myelin sheath formation in mouse and human oligodendrocytes, overexpression of wildtype or constitutively active SKAP2 enhances the migratory capacity of murine oligodendrocytes. In summary, we present SKAP2 as modulator of cytoskeletal dynamics regulating OPC migration, differentiation and myelin sheath formation.

Summary Limited access to human oligodendrocytes impairs better understanding of oligodendrocyte pathology in myelin diseases. Here, we describe a method to robustly convert human fibroblasts directly into oligodendrocyte-like cells (dc-hiOLs), which allows evaluation of remyelination-promoting compounds and disease modeling. Ectopic expression of SOX10, OLIG2, and NKX6.2 in human fibroblasts results in rapid generation of O4+ cells, which further differentiate into MBP+ mature oligodendrocyte-like cells within 16 days. dc-hiOLs undergo chromatin remodeling to express oligodendrocyte markers, ensheath axons, and nanofibers in vitro, respond to promyelination compound treatment, and recapitulate in vitro oligodendroglial pathologies associated with Pelizaeus-Merzbacher leukodystrophy related to PLP1 mutations. Furthermore, DNA methylome analysis provides evidence that the CpG methylation pattern significantly differs between dc-hiOLs derived from fibroblasts of young and old donors, indicating the maintenance of the source cells’ “age.” In summary, dc-hiOLs represent a reproducible technology that could contribute to personalized medicine in the field of myelin diseases., Graphical abstract, Highlights • SOX10, OLIG2, and NKX6.2 directly convert human fibroblasts into dc-hiOLs in 16 days • dc-hiOLs express key oligodendrocyte markers • dc-hiOLs preserve the epigenetic age of donor cells • dc-hiOLs from PMD patients show maturation deficit and vulnerability to cell death, In this article, Kuhlmann and colleagues show that human fibroblasts can be directly converted into oligodendrocyte-like cells (dc-hiOLs) upon overexpression of SOX10, OLIG2, and NKX6.2. dc-hiOLs undergo chromatin remodeling to activate oligodendrocyte-related genes, perform ensheathment in vitro, and maintain the epigenetic age of donor cells. The applicability of dc-hiOLs in promyelination compound screening and disease-modeling studies is demonstrated.

Bees (Anthophila) represent a critical taxon for the ecosystem service of pollination and hence have received great scientific attention. The more than 20,000 known species of bees are grouped in seven families. Yet, the relationships between bee families are not entirely clear, and specifically, the position of Melittidae and their monophyly has been discussed in the past. Here, we present the most comprehensive mitogenomic phylogeny of bees including five members of Melittidae from two sub- families and three tribes. Our results suggest monophyly of the family Melittidae and further support their basal position. The data also support the two subfamilies, but are not in line with current assignment of tribes. Our results show, despite advancement with transcriptomic and whole genomic data, the value of mitochondrial data for the reconstruction of phylogenies.

Background The efficient and robust statistical analysis of the shape of plant organs of different cultivars is an important investigation issue in plant breeding and enables a robust cultivar description within the breeding progress. Laserscanning is a highly accurate and high resolution technique to acquire the 3D shape of plant surfaces. The computation of a shape based principal component analysis (PCA) built on concepts from continuum mechanics has proven to be an effective tool for a qualitative and quantitative shape examination. Results The shape based PCA was used for a statistical analysis of 140 sugar beet roots of different cultivars. The calculation of the mean sugar beet root shape and the description of the main variations was possible. Furthermore, unknown and individual tap roots could be attributed to their cultivar by means of a robust classification tool based on the PCA results. Conclusion The method demonstrates that it is possible to identify principal modes of root shape variations automatically and to quantify associated variances out of laserscanned 3D sugar beet tap root models. The introduced approach is not limited to the 3D shape description by laser scanning. A transfer to 3D MRI or radar data is also conceivable.

Species richness is the most commonly used metric to quantify biodiversity. However, examining dark diversity, the group of missing species which can potentially inhabit a site, can provide a more thorough understanding of the processes influencing observed biodiversity and help evaluate the restoration potential of local habitats. So far, dark diversity has mainly been studied for specific habitats or large‐scale landscapes, while less attention has been given to variation across broad environmental gradients or as a result of local conditions and biotic interactions. In this study, we investigate the importance of local environmental conditions in determining dark diversity and observed richness in plant communities across broad environmental gradients. Using the ecospace concept, we investigate how these biodiversity measures relate to abiotic gradients (defined as position), availability of biotic resources (defined as expansion), spatiotemporal extent of habitats (defined as continuity), and species interactions through competition. Position variables were important for both observed diversity and dark diversity, some with quadratic relationships, for example, plant richness showing a unimodal response to soil fertility corresponding to the intermediate productivity hypothesis. Interspecific competition represented by community mean Grime C had a negative effect on plant species richness. Besides position‐related variables, organic carbon was the most important variable for dark diversity, indicating that in late‐succession habitats such as forests and shrubs, dark diversity is generally low. The importance of highly competitive species indicates that intermediate disturbance, such as grazing, may facilitate higher species richness and lower dark diversity., Dark diversity, the group of missing species that can potentially inhabit a site, is strongly related to abiotic conditions or habitat types. Dark diversity is positively correlated with competition estimated using community mean Grime C and negatively correlated with soil organic carbon indicating that dark diversity increases at sites dominated by few, but abundant competitive species, but is reduced in undisturbed sites with long‐term stability.

Proshchalykin, M. Yu., Kuhlmann, M. (2020): NEW DATA ON BEES OF THE GENUS COLLETES LATREILLE (HYMENOPTERA: COLLETIDAE) FROM RUSSIA. Far Eastern Entomologist 406: 21-26, DOI: 10.25221/fee.406.3, URL: http://dx.doi.org/10.25221/fee.406.3

In soluble methane monooxygenase enzymes (sMMO), dioxygen (O2) is activated at a diiron(II) center to form an oxodiiron(IV) intermediate Q that performs the challenging oxidation of methane to meth...

The association of antimicrobial resistance (AMR) with climatic factors gained higher attention since resistance increased with increasing local temperatures in the USA. We aimed to investigate whether the explanatory strength of climatic factors holds true in a region encompassing diverse healthcare systems, like Europe. In particular, we determined whether exposure to temporal climate warming is associated with an increase in AMR prevalence for clinically relevant pathogens. A 30-country cross-sectional study was conducted. The six-year prevalence of carbapenem-resistant Pseudomonas aeruginosa (CRPA), Klebsiella pneumoniae (CRKP), Multiresistant Escherichia coli (MREC), and Methicillin-resistant Staphylococcus aureus (MRSA) was determined based on > 900 k clinical isolates. Bi- and multivariate analysis were performed to identify associations with climatic variables using healthcare and socio-economic confounders. CRPA was significantly associated with the warm-season change in temperature, which, alongside corruption perception, explained 78% of total CRPA variance. Accordingly, a 0.5 °C increase of year-wise temperature change (exposition) resulted in a 1.02-fold increase (p = 0.035) in CRPA prevalence (outcome). For a given country, exposition status doubled the odds of outcome attainment compared to non-exposition (OR = 2.03, 95%-CI [1.03–3.99]). Moreover, we found significant associations of CRKP, MREC, and MRSA with the warm-season mean temperature, which had a higher contribution to MRSA variance explanation than outpatient antimicrobial drug use. We identified a novel association between AMR and climatic factors in Europe, which reveals two aspects: climatic factors significantly contribute to the explanation of AMR in different types of healthcare systems, while climate change (i.e. warming) might increase AMR transmission, in particular CRPA.

Context Patients with classic congenital adrenal hyperplasia (CAH) often do not achieve their full growth potential. Adrenarche may accelerate bone maturation and thereby result in decreased growth in CAH. Objective The study aimed to analyze the impact of growth during adrenarche on final height of adequately treated classic CAH patients. Methods This retrospective, multicenter study (4 academic pediatric endocrinology centers) included 41 patients with classical CAH, born 1990-2012. We assessed skeletal maturation (bone age), growth velocity, and (projected) adult height outcomes, and analyzed potential influencing factors, such as sex, genotype, and glucocorticoid therapy. Results Patients with classic CAH were shorter than peers (−0.4 SDS ± 0.8 SD) and their parents (corrected final height −0.6 SDS ± 1.0 SD). Analysis of growth during adrenarche revealed 2 different growth patterns: patients with accelerating bone age (49%), and patients with nonaccelerating bone age relative to chronological age (BA-CA). Patients with accelerating BA-CA were taller than the normal population during adrenarche years (P = 0.001) and were predicted to achieve lower adult height SDS (−0.9 SDS [95% CI, −1.3; −0.5]) than nonaccelerating patients when assessed during adrenarche (0.2 SDS [95% CI, −0.3; 0.8]). Final adult height was similarly reduced in both accelerating and nonaccelerating BA-CA groups (−0.4 SDS [95% CI, −0.9; 0.1] vs −0.3 SDS [95% CI, [−0.8; 0.1]). Conclusion Patients with and without significant bone age advancement, and thus differing height prediction during adrenarche, showed similar (predicted) final height when reassessed during pubertal years. Bone age alone should not be used during adrenarche as clinical marker for metabolic control in CAH treatment.

Increasing goose population sizes gives rise to conflicts with human socioeconomic interests and in some circumstances conservation interests. Grazing by high abundances of geese in grasslands is postulated to lead to a very short and homogeneous sward height negatively affecting cover for breeding meadow birds and impacting survival of nests and chicks. We studied the effects of spring grazing barnacle geese Branta leucopsis and brent geese Branta bernicla on occupancy of extensively farmed freshwater grasslands by nesting and brood‐rearing waders on the island Mandø in the Danish Wadden Sea. We hypothesized that goose grazing would lead to a shorter grass sward, negatively affecting the field occupancy by territorial/nesting and chick‐rearing waders, particularly species preferring taller vegetation. Goose grazing led to a short grass sward (, Grazing by high abundances of geese in grasslands is postulated to lead to a very short and homogeneous sward height negatively affecting cover for breeding meadow birds and ultimately impacting survival of nests and chicks. Despite very intensive goose grazing in spring, our field study could not detect any negative effect on the field occupancy by nesting nor chick‐rearing waders.

MS-derived oligodendrocytes conserve their ability to fully interact with axons and glial cells in vivo., Remyelination failure in multiple sclerosis (MS) is associated with a migration/differentiation block of oligodendroglia. The reason for this block is highly debated. It could result from disease-related extrinsic or intrinsic regulators in oligodendroglial biology. To avoid confounding immune-mediated extrinsic effect, we used an immune-deficient mouse model to compare induced pluripotent stem cell–derived oligodendroglia from MS and healthy donors following engraftment in the developing CNS. We show that the MS-progeny behaves and differentiates into oligodendrocytes to the same extent as controls. They generate equal amounts of myelin, with bona fide nodes of Ranvier, and promote equal restoration of their host slow conduction. MS-progeny expressed oligodendrocyte- and astrocyte-specific connexins and established functional connections with donor and host glia. Thus, MS oligodendroglia, regardless of major immune manipulators, are intrinsically capable of myelination and making functional axo-glia/glia-glia connections, reinforcing the view that the MS oligodendrocyte differentiation block is not from major intrinsic oligodendroglial deficits.

G-protein-coupled receptors (GPCRs), especially chemokine receptors, play a central role in the regulation of T cell migration. Various GPCRs are upregulated in activated CD4 T cells, including P2Y10, a putative lysophospholipid receptor that is officially still considered an orphan GPCR, i.e., a receptor with unknown endogenous ligand. Here we show that in mice lacking P2Y10 in the CD4 T cell compartment, the severity of experimental autoimmune encephalomyelitis and cutaneous contact hypersensitivity is reduced. P2Y10-deficient CD4 T cells show normal activation, proliferation and differentiation, but reduced chemokine-induced migration, polarization, and RhoA activation upon in vitro stimulation. Mechanistically, CD4 T cells release the putative P2Y10 ligands lysophosphatidylserine and ATP upon chemokine exposure, and these mediators induce P2Y10-dependent RhoA activation in an autocrine/paracrine fashion. ATP degradation impairs RhoA activation and migration in control CD4 T cells, but not in P2Y10-deficient CD4 T cells. Importantly, the P2Y10 pathway appears to be conserved in human T cells. Taken together, P2Y10 mediates RhoA activation in CD4 T cells in response to auto-/paracrine-acting mediators such as LysoPS and ATP, thereby facilitating chemokine-induced migration and, consecutively, T cell-mediated diseases., P2Y10 is a G-protein-coupled receptor that is expressed in CD4 T cells. Here authors show that its ligands, lysophosphatidylserine and ATP, are induced in T cells upon chemokine stimulation and regulate RhoA activation and migration through an autocrine/paracrine loop.

The impact of pollinator community diversity on trait matching in plant-pollinator interactions is poorly studied, even though many mutualisms involve multiple interaction partners. We studied 10 communities in which one to three species of oil-collecting

Illuminating the mechanisms of inflorescence architecture of grain crops that feed our world may strengthen the goal towards sustainable agriculture. Lateral spikelet development of barley (Hordeum vulgare L.) is such an example of a floral architectural trait regulated by VRS1 (Vulgare Row-type Spike 1 or Six-rowed Spike 1, syn. HvHOX1). Its lateral spikelet-specific expression and the quantitative nature of suppressing spikelet development were previously shown in barley. However, the mechanistic function of this gene and its paralog HvHOX2 on spikelet development is still fragmentary.Here, we show that these duplicated transcription factors (TFs) have contrasting nucleotide diversity in various barley genotypes and several Hordeum species. Despite this difference, both proteins retain their basic properties of the homeodomain leucine zipper class I family of TFs. During spikelet development, these genes exhibit similar spatiotemporal expression patterns yet with anticyclic expression levels. A gene co-expression network analysis suggested that both have an ancestral relationship but their functions appear antagonistic to each other, i.e., HvHOX1 suppresses whereas HvHOX2 rather promotes spikelet development. Our transgenic promoter-swap analysis showed that HvHOX2 can restore suppressed lateral spikelets when expression levels are increased; however, at its low endogenous expression level, HvHOX2 appears dispensable for spikelet development. Collectively, this study proposes that the dosage of the two antagonistic TFs, HvHOX1 and HvHOX2, influence spikelet development in barley.

The spotted wing drosophila (SWD), Drosophila suzukii, is a major invasive fruit pest. There is strong consensus that low temperature is among the main drivers of SWD population distribution, and the invasion success of SWD is also linked to its thermal plasticity. Most studies on ectotherm cold tolerance focus on exposure to a single stressful temperature but here we investigated how cold stress intensity affected survival duration across a broad range of low temperatures (−7 to +3 °C). The analysis of Lt50 at different stressful temperatures (Thermal Death Time curve - TDT) is based on the suggestion that cold injury accumulation rate increases exponentially with the intensity of thermal stress. In accordance with the hypothesis, Lt50 of SWD decreased exponentially with temperature. Further, comparison of TDT curves from flies acclimated to 15, 19 and 23 °C, respectively, showed an almost full compensation with acclimation such that the temperature required to induce mortality over a fixed time decreased almost 1 °C per °C lowering of acclimation temperature. Importantly, this change in cold tolerance with acclimation was uniform across the range of moderate to intense cold stress exposures examined. To understand if cold stress at moderate and intense exposures affects the same physiological systems we examined how physiological markers/symptoms of chill injury developed at different intensities of the cold stress. Specifically, hsp23 expression and extracellular [K+] were measured in flies exposed to different intensities of cold stress (−6, −2 and +2 °C) and at various time points corresponding to the same progression of injury (equivalent to 1/3, 2/3 or 3/3 of Lt50). The different cold stress intensities all triggered hsp23 expression following 2 h of recovery, but patterns of expression differed. At the most intense cold stress (−6 and −2 °C) a gradual increase with time was found. In contrast, at +2 °C an initial increase was followed by a dissipating expression. A gradual perturbation of ion balance (hyperkalemia) was also found at all three cold stress intensities examined, with only slight dissimilarities between treatment temperatures. Despite some differences between the three cold intensities examined, the results generally support the hypothesis that intense and moderate cold stress induces the same physiological perturbation. This suggests that cold stress experienced during natural fluctuating conditions is additive and the results also illustrate that the rate of injury accumulation increases dramatically (exponentially) with decreasing temperature (increasing stress).

Multiple sclerosis (MS) is the most frequent demyelinating disease in young adults and despite significant advances in immunotherapy, disease progression still cannot be prevented. Promotion of remyelination, an endogenous repair mechanism resulting in the formation of new myelin sheaths around demyelinated axons, represents a promising new treatment approach. However, remyelination frequently fails in MS lesions, which can in part be attributed to impaired differentiation of oligodendroglial progenitor cells into mature, myelinating oligodendrocytes. The reasons for impaired oligodendroglial differentiation and defective remyelination in MS are currently unknown. To determine whether intrinsic oligodendroglial factors contribute to impaired remyelination in relapsing–remitting MS (RRMS), we compared induced pluripotent stem cell-derived oligodendrocytes (hiOL) from RRMS patients and controls, among them two monozygous twin pairs discordant for MS. We found that hiOL from RRMS patients and controls were virtually indistinguishable with respect to remyelination-associated functions and proteomic composition. However, while analyzing the effect of extrinsic factors we discovered that supernatants of activated peripheral blood mononuclear cells (PBMCs) significantly inhibit oligodendroglial differentiation. In particular, we identified CD4+ T cells as mediators of impaired oligodendroglial differentiation; at least partly due to interferon-gamma secretion. Additionally, we observed that blocked oligodendroglial differentiation induced by PBMC supernatants could not be restored by application of oligodendroglial differentiation promoting drugs, whereas treatment of PBMCs with the immunomodulatory drug teriflunomide prior to supernatant collection partly rescued oligodendroglial differentiation. In summary, these data indicate that the oligodendroglial differentiation block is not due to intrinsic oligodendroglial factors but rather caused by the inflammatory environment in RRMS lesions which underlines the need for drug screening approaches taking the inflammatory environment into account. Combined, these findings may contribute to the development of new remyelination promoting strategies. Electronic supplementary material The online version of this article (10.1007/s00401-020-02217-8) contains supplementary material, which is available to authorized users.

Oligodendrocytes are extensively coupled to astrocytes, a phenomenon ensuring glial homeostasis and maintenance of central nervous system myelin. Molecular disruption of this communication occurs in demyelinating diseases such as multiple sclerosis. Less is known about the vulnerability and reconstruction of the panglial network during adult demyelination‐remyelination. Here, we took advantage of lysolcithin‐induced demyelination to investigate the expression dynamics of the oligodendrocyte specific connexin 47 (Cx47) and to some extent that of astrocyte Cx43, and whether this dynamic could be modulated by grafted induced pluripotent stem cell (iPSC)‐neural progeny. Our data show that disruption of Cx43‐Cx47 mediated hetero‐cellular gap‐junction intercellular communication following demyelination is larger in size than demyelination. Loss of Cx47 expression is timely rescued during remyelination and accelerated by the grafted neural precursors. Moreover, mouse and human iPSC‐derived oligodendrocytes express Cx47, which co‐labels with astrocyte Cx43, indicating their integration into the panglial network. These data suggest that in rodents, full lesion repair following transplantation occurs by panglial reconstruction in addition to remyelination. Targeting panglial elements by cell therapy or pharmacological compounds may help accelerating or stabilizing re/myelination in myelin disorders., Main Points Loss of oligodendrocyte Cx47 expression caused by lysolecithin‐induced demyelination is timely rescued during remyelination.Panglial repair correlates with remyelination and is accelerated by the grafted iPSC‐neural precursor cells.

Cleavage of double-stranded RNA is described as an evolutionary conserved host defense mechanism against viral infection. Small RNAs are the product and triggers of post transcriptional gene silencing events. Up until now, the relevance of this mechanism for SARS-CoV-2-directed immune responses remains elusive. Herein, we used high throughput sequencing to profile the plasma of active and convalescent COVID-19 patients for the presence of small circulating RNAs. The existence of SARS-CoV-2 derived small RNAs in plasma samples of mild and severe COVID-19 cases is described. Clusters of high siRNA abundance were discovered, homologous to the nsp2 3′-end and nsp4 virus sequence. Four virus-derived small RNA sequences have the size of human miRNAs, and a target search revealed candidate genes associated with ageusia and long COVID symptoms. These virus-derived small RNAs were detectable also after recovery from the disease. The additional analysis of circulating human miRNAs revealed differentially abundant miRNAs, discriminating mild from severe cases. A total of 29 miRNAs were reduced or absent in severe cases. Several of these are associated with JAK-STAT response and cytokine storm.

The subfamily Drusinae (Limnephilidae, Trichoptera) comprises a range of species exhibiting differently shaped head capsules in their larval stages. These correspond to evolutionary lineages pursuing different larval feeding ecologies, each of which uses a different hydraulic niche: scraping grazers and omnivorous shredders sharing rounded head capsules and filtering carnivores with indented and corrugated head capsules. In this study, we assess whether changes in head capsule morphology are reflected by changes in internal anatomy of Drusinae heads. To this end, internal and external head morphology was visualized using µCT methods and histological sections in three Drusinae species – Drusus bosnicus, D. franzi and D. discolor – representing the three evolutionary lineages. Our results indicate that Drusinae head musculature is highly conserved across the evolutionary lineages with only minute changes between taxa. Conversely, the tentorium is reduced in D. discolor, the species with the most aberrant head capsule investigated here. Integrating previous research on Drusinae head anatomy, we propose a fundamental Drusinae blueprint comprising 29 cephalic muscles and discuss significance of larval head capsule corrugation in Trichoptera.

Iron–sulfur (Fe–S) centers are versatile building blocks in biological electron transfer chains because their redox potentials may cover a wide potential range depending on the type of the cluster and the specific protein environment. Resonance Raman (RR) spectroscopy is widely used to analyze structural properties of such cofactors, but it remains still a challenge to disentangle the overlapping signals of metalloproteins carrying several Fe–S centers. In this work, we combined RR spectroscopy with protein engineering and X‐ray crystallography to address this issue on the basis of the oxygen‐tolerant membrane‐bound hydrogenase from Ralstonia eutropha that catalyzes the reversible conversion of hydrogen into protons and electrons. Besides the NiFe‐active site, this enzyme harbors three different Fe–S clusters constituting an electron relay with a distal [4Fe–4S], a medial [3Fe–4S], and an unusual proximal [4Fe–3S] cluster that may carry a hydroxyl ligand in the superoxidized state. RR spectra were measured from protein crystals by varying the crystal orientation with respect to the electric field vector of the incident laser to achieve a preferential RR enhancement for individual Fe–S clusters. In addition to spectral discrimination by selective reduction of the proximal cluster, protein engineering allowed for transforming the proximal and medial cluster into standard cubane‐type [4Fe–4S] centers in the C19G/C120G and P242C variants, respectively. The latter variant was structurally characterized for the first time in this work. Altogether, the entirety of the RR data provided the basis for identifying the vibrational modes characteristic of the various cluster states in this “model” enzyme as a prerequisite for future studies of complex (FeS)‐based electron transfer chains., ​

Plant-pollinator interactions are often highly specialised, which may be a consequence of co-evolution. Yet when plants and pollinators co-evolve, it is not clear if this will also result in frequent cospeciation. Here, we investigate the mutual evolutionary history of South African oil-collecting Rediviva bees and their Diascia host plants, in which the elongated forelegs of female Rediviva have been suggested to coevolve with the oil-producing spurs of their Diascia hosts. After controlling for phylogenetic nonindependence, we found Rediviva foreleg length to be significantly correlated with Diascia spur length, suggestive of co-evolution. However, as trait correlation could also be due to pollinator shifts, we tested if cospeciation or pollinator shifts have dominated the evolution of Rediviva-Diascia interactions by analysing phylogenies in a cophylogenetic framework. Distance-based cophylogenetic analyses (PARAFIT, PACo) indicated significant congruence of the two phylogenies under most conditions. Yet, we found that phylogenetic relatedness was correlated with ecological similarity (the spectrum of partners that each taxon interacted with) only for Diascia but not for Rediviva, suggesting that phylogenetic congruence might be due to phylogenetic tracking by Diascia of Rediviva rather than strict (reciprocal) co-evolution. Furthermore, event-based reconciliation using a parsimony approach (CORE-PA) on average revealed only 11-13 cospeciation events but 58-80 pollinator shifts. Probabilistic cophylogenetic analyses (COALA) supported this trend (8-29 cospeciations vs. 40 pollinator shifts). Our study suggests that diversification of Diascia has been largely driven by Rediviva (phylogenetic tracking, pollinator shifts) but not vice versa. Moreover, our data suggest that, even in co-evolving mutualisms, cospeciation events might occur only infrequently.

When insects are cooled, they initially lose their ability to perform coordinated movements at their critical thermal minima (CTmin). At a slightly lower temperature, they enter a state of complete paralysis (chill coma onset temperature - CCO) and if they are returned to permissive temperatures they regain function after a recovery period which is termed chill coma recovery time (CCRT). These three phenotypes (CTmin, CCO, and CCRT) are all popular measures of insect cold tolerance and it is therefore important to characterize the physiological processes that are responsible for these phenotypes. In the present study we measured extracellular field potentials in the central nervous system (CNS) and muscle membrane potential (Vm) during cooling and recovery in three Drosophila species that have different cold tolerances. With these measurements we assess the role of the CNS and muscle Vm in setting the lower thermal limits (CTmin and CCO) and in delaying chill coma recovery (CCRT). The experiments suggest that entry into chill coma is primarily caused by the onset of a spreading depolarization in the CNS for all three species. In the two most cold-sensitive species we observed that the loss of CNS function was followed closely by a depolarization of muscle Vm which is known to compromise muscle function. When flies are returned to benign temperature after a cold exposure we observe a rapid recovery of CNS function, but functional recovery was delayed by a slower recovery of muscle polarization. Thus, we demonstrate the primacy of different physiological systems (CNS vs. muscle) as determinants of the most commonly used cold tolerance measures for insects (CTmin vs. CCRT).

1. Species of Drosophilidae are frequently used as model organisms, but their relationships with the environment, particularly in immature stages, remain poorly known. 2. This is the most comprehensive survey to date of fruit‐breeding drosophilids and their hosts in the Neotropics. Drosophilid host‐utilisation patterns were analysed as to geographic origin (native versus exotic) and level of specialisation. 3. The 180 species of plants recorded as drosophilid hosts are distributed across the main Angiosperm lineages and fleshy‐fruited orders; plant families that hosted the greatest number of drosophilid species were Arecaceae, Moraceae, and Myrtaceae. The 100 nominal drosophilid species recorded breeding in fruits belong to just over one‐third of Neotropical genera; most species (91) belong to Drosophila . Drosophilid species with the greatest resource breadth were Drosophila simulans , Drosophila nebulosa , and Zaprionus indianus. 4. Exotic drosophilids breed in more plant species than Neotropical drosophilids and use exotic hosts more frequently, possibly because they are generalists that have survived the trial of introduction and establishment in the Neotropics. Native drosophilids are more variable in resource breadth and sometimes adopt exotic hosts. 5. Amongst the 49 drosophilids with enough records for analysis (> 4), 48 were categorised as generalists. One possible explanation for such overwhelming generalism is the high diversity of Neotropical habitat or hosts. A second, non‐exclusive explanation, suggested by recent studies and empirically supported by the absence of host specialisation found in this study, is that drosophilids could be selective of the dominant yeasts and bacteria in host tissue, and not of the hosts themselves.

Summary Reliably generating rice varieties with low glycaemic index (GI) is an important nutritional intervention given the high rates of Type II diabetes incidences in Asia where rice is staple diet. We integrated a genome‐wide association study (GWAS) with a transcriptome‐wide association study (TWAS) to determine the genetic basis of the GI in rice. GWAS utilized 305 re‐sequenced diverse indica panel comprising ~2.4 million single nucleotide polymorphisms (SNPs) enriched in genic regions. A novel association signal was detected at a synonymous SNP in exon 2 of LOC_Os05g03600 for intermediate‐to‐high GI phenotypic variation. Another major hotspot region was predicted for contributing intermediate‐to‐high GI variation, involves 26 genes on chromosome 6 (GI6.1). These set of genes included GBSSI, two hydrolase genes, genes involved in signalling and chromatin modification. The TWAS and methylome sequencing data revealed cis‐acting functionally relevant genetic variants with differential methylation patterns in the hot spot GI6.1 region, narrowing the target to 13 genes. Conversely, the promoter region of GBSSI and its alternative splicing allele (G allele of Wx a) explained the intermediate‐to‐high GI variation. A SNP (C˃T) at exon‐10 was also highlighted in the preceding analyses to influence final viscosity (FV), which is independent of amylose content/GI . The low GI line with GC haplotype confirmed soft texture, while other two low GI lines with GT haplotype were characterized as hard and cohesive. The low GI lines were further confirmed through clinical in vivo studies. Gene regulatory network analysis highlighted the role of the non‐starch polysaccharide pathway in lowering GI.

In multiple sclerosis, demyelination occurs as a consequence of chronic autoimmunity in the central nervous system causing progressive neurological impairment in patients. After a demyelinating event, new myelin sheaths are formed by adult oligodendroglial progenitor cells; a process called remyelination. However, remyelination often fails in multiple sclerosis due to insufficient recruitment and differentiation of oligodendroglial precursor cells. A pivotal role for the two-pore-domain potassium (K2P ) channel, TASK1, has already been proven for an animal model of multiple sclerosis. However, the mechanisms underlying the TASK1-mediated effects are still elusive. Here, we tested the role of TASK1 channels in oligodendroglial differentiation and remyelination after cuprizone-induced demyelination in male mice. We found TASK1 channels to be functionally expressed on primary murine and human, pluripotent stem cell-derived oligodendrocytes. Lack of TASK1 channels resulted in an increase of mature oligodendrocytes in vitro as well as a higher number of mature oligodendrocytes and accelerated developmental myelination in vivo. Mechanistically, Task1-deficient cells revealed a higher amount of phosphorylated WNK1, a kinase known to be involved in the downstream signaling of the myelination regulator LINGO-1. Furthermore, we analyzed the effect of genetic TASK1 ablation or pharmacological TASK1 inhibition on disease-related remyelination. Neither channel inhibition nor lack of TASK1 channels promoted remyelination after pathological demyelination. In summary, we conclude that functional TASK1 channels participate in the modulation of differentiating oligodendroglial cells in a previously unknown manner. However, while being involved in developmental myelination our data suggest that TASK1 channels have no major effect on remyelination.

Broadly neutralizing antibodies (bNAbs) are among the most promising strategies to achieve long-term control of HIV-1 in the absence of combination antiretroviral therapy. Passive administration of such antibodies in patients efficiently decreases HIV-1 viremia, but is limited by the serum half-life of the protein. Here, we investigated whether antibody-secreting hematopoietic cells could overcome this problem. We genetically modified human CD34(+) hematopoietic stem and progenitor cells (HSPCs) to secrete bNAbs and transplanted them into immunodeficient mice. We found that the gene-modified cells engraft and stably secrete antibodies in the peripheral blood of the animals for the 9 months of the study. Antibodies were predominantly expressed by human HSPC-derived T- and B cells. Importantly, we found that secreted PGT128 was able to delay HIV-1 viremia in vivo and also prevent a decline in CD4(+) cells. Gene-modified cells were maintained in bone marrow and were also detected in spleen, thymus, lymph nodes, and gut-associated lymphoid tissue. These data indicate that the bNAb secretion from HSPC-derived cells in mice is functional and can affect viral infection and CD4(+) cell maintenance. This study paves the way for potential applications to other diseases requiring long-lasting protein or antibody delivery.

Neuroinflammation and oligodendroglial cytoplasmic α‐synuclein (α‐syn) inclusions (GCIs) are important neuropathological characteristics of multiple system atrophy (MSA). GCIs are known to interfere with oligodendroglial maturation and consequently result in myelin loss. The neuroinflammatory phenotype in the context of MSA, however, remains poorly understood. Here, we demonstrate MSA‐associated neuroinflammation being restricted to myeloid cells and tightly linked to oligodendroglial α‐syncleinopathy. In human putaminal post‐mortem tissue of MSA patients, neuroinflammation was observed in white matter regions only. This locally restricted neuroinflammation coincided with elevated numbers of α‐syn inclusions, while gray matter with less α‐synucleinopathy remained unaffected. In order to analyze the temporal pattern of neuroinflammation, a transgenic mouse model overexpressing human α‐syn under the control of an oligodendrocyte‐specific myelin basic protein (MBP) promoter (MBP29‐hα‐syn mice) was assessed in a pre‐symptomatic and symptomatic disease stage. Strikingly, we detected an increased neuroinflammation in regions with a high α‐syn load, the corpus callosum and the striatum, of MBP29‐hα‐syn mice, already at a pre‐symptomatic stage. Furthermore, this inflammatory response was restricted to myeloid cells being highly proliferative and showing an activated, phagocytic phenotype. In contrast, severe astrogliosis was observed only in gray matter regions of MSA patients as well as MBP29‐hα‐syn mice. To further characterize the influence of oligodendrocytes on initiation of the myeloid immune response, we performed RNA sequencing analysis of α‐syn overexpressing primary oligodendrocytes. A distinct gene expression profile including upregulation of cytokines important for myeloid cell attraction and proliferation was detected in α‐syn overexpressing oligodendrocytes. Additionally, microdissected tissue of MBP29‐hα‐syn mice exhibited a similar cellular gene expression profile in white matter regions even pre‐symptomatically. Collectively, these results imply an early crosstalk between neuroinflammation and oligodendrocytes containing α‐syn inclusions leading to an immune response locally restricted to white matter regions in MSA.

The bone morphogenetic protein (BMP) type I receptors ALK2 and ALK3 are essential for expression of hepcidin, a key iron regulatory hormone. In mice, hepatocyte-specific Alk2 deficiency leads to moderate iron overload with periportal liver iron accumulation, while hepatocyte-specific Alk3 deficiency leads to severe iron overload with centrilobular liver iron accumulation and a more marked reduction of basal hepcidin levels. The objective of this study was to investigate whether the two receptors have additive roles in hepcidin regulation. Iron overload in mice with hepatocyte-specific Alk2 and Alk3 (Alk2/3) deficiency was characterized and compared to hepatocyte-specific Alk3 deficient mice. Co-immunoprecipitation studies were performed to detect the formation of ALK2 and ALK3 homodimer and heterodimer complexes in vitro in the presence and absence of ligands. The iron overload phenotype of hepatocyte-specific Alk2/3-deficient mice was more severe than that of hepatocyte-specific Alk3-deficient mice. In vitro co-immunoprecipitation studies in Huh7 cells showed that ALK3 can homodimerize in absence of BMP2 or BMP6. In contrast, ALK2 did not homodimerize in either the presence or absence of BMP ligands. However, ALK2 did form heterodimers with ALK3 in the presence of BMP2 or BMP6. ALK3-ALK3 and ALK2-ALK3 receptor complexes induced hepcidin expression in Huh7 cells. Our data indicate that: (I) ALK2 and ALK3 have additive functions in vivo, as Alk2/3 deficiency leads to a greater degree of iron overload than Alk3 deficiency; (II) ALK3, but not ALK2, undergoes ligand-independent homodimerization; (III) the formation of ALK2-ALK3 heterodimers is ligand-dependent and (IV) both receptor complexes functionally induce hepcidin expression in vitro.

I used 20 years of sampling data to describe the dynamics of the invasion of the rusty crayfish, Faxonius rusticus (Girard, 1852), of two stream systems in New York state (USA) and compare this invasion to invasions of this species of lakes elsewhere in North America. Rusty crayfish typically increased rapidly in abundance while displacing native crayfishes, becoming > 90% of crayfish captured in an average of 9 years. As in lakes, overall crayfish abundance increased as the invasion progressed. The F. rusticus population spread at a median rate of 3 km yr–1 upstream and 8.1 km yr–1 downstream. The hypothesis that an Allee effect would occur at the invasion front was not supported, since the rate of change of F. rusticus abundance did not increase as the invasion progressed. Qualitatively, the dynamics of F. rusticus’s invasion of streams are similar to previous findings for lakes, suggesting that the main processes affecting the invasions are similar.

Bacterial protein degradation is a regulated process aided by protease adaptors that alter specificity of energy-dependent proteases. In Caulobacter crescentus, cell cycle–dependent protein degradation depends on a hierarchy of adaptors, such as the dimeric RcdA adaptor, which binds multiple cargo and delivers substrates to the ClpXP protease. RcdA itself is degraded in the absence of cargo, and how RcdA recognizes its targets is unknown. Here, we show that RcdA dimerization and cargo binding compete for a common interface. Cargo binding separates RcdA dimers, and a monomeric variant of RcdA fails to be degraded, suggesting that RcdA degradation is a result of self-delivery. Based on HDX-MS studies showing that different cargo rely on different regions of the dimerization interface, we generate RcdA variants that are selective for specific cargo and show cellular defects consistent with changes in selectivity. Finally, we show that masking of cargo binding by dimerization also limits substrate delivery to restrain overly prolific degradation. Using the same interface for dimerization and cargo binding offers an ability to limit excess protease adaptors by self-degradation while providing a capacity for binding a range of substrates.

ObjectiveTo determine whether B-cell presence in brainstem and white matter (WM) lesions is associated with poorer pathological and clinical characteristics in advanced MS autopsy cases.MethodsAutopsy tissue of 140 MS and 24 control cases and biopsy tissue of 24 patients with MS were examined for CD20+ B cells and CD138+ plasma cells. The presence of these cells was compared with pathological and clinical characteristics. In corresponding CSF and plasma, immunoglobulin (Ig) G ratio and oligoclonal band (OCB) patterns were determined. In a clinical cohort of 73 patients, the presence of OCBs was determined during follow-up and compared to status at diagnosis.ResultsIn 34% of active and 71% of mixed active/inactive lesions, B cells were absent, which correlated with less pronounced meningeal B-cell infiltration (p < 0.0001). The absence of B cells and plasma cells in brainstem and WM lesions was associated with a longer disease duration (p = 0.001), less frequent secondary progressive MS compared with relapsing and primary progressive MS (p < 0.0001 and p = 0.046, respectively), a lower proportion of mixed active/inactive lesions (p = 0.01), and less often perivascular T-cell clustering (p < 0.0001). Moreover, a lower CSF IgG ratio (p = 0.006) and more frequent absence of OCBs (p < 0.0001) were noted. In a clinical cohort, numbers of patients without OCBs in CSF were increased at follow-up (27.4%).ConclusionsThe absence of B cells is associated with a favorable clinical and pathological profile. This finding may reflect extremes of a continuum of genetic or environmental constitution, but also a regression of WM humoral immunopathology in the natural course of advanced MS.

Most species of the Colletes succinctus group sensu Noskiewicz, 1936 are taxonomically uncertain. This study has chosen an integrative approach, including pollen analysis, morphology, male genitalia, morphometry, cuticle sculpture and DNA-barcoding (CO1) to investigate the five species that were reported from Austria. It includes a detailed analysis of the male genitalia and the first description of the C. pannonicus male. A syntype male from the island of Crete was designated as the lectotype of Colletes succinctus brevigena Noskiewicz, 1936 to fix the species identity. New distinguishing characters were found: in females the shape of the dorsal end of the fovea facialis and, in both sexes, the structure of maxillary palpi, as well as the different puncturation on the mesopleura. Unknown structures on sterna and genitalia of the males proved to be reliable morphological characters. An identification key is provided for all studied species. Morphometry of females did not allow a clear distinction of species. CO1 sequencing confirmed previous studies that only C. collaris clearly deviates from the other species, including C. pannonicus that was analysed for the first time. Pollen analysis showed polylectic, as well as oligolectic, pollen-collecting behaviour. The collected pollen of C. pannonicus confirmed the field observations that this species is strictly oligolectic on Tripolium pannonicum. Due to pronounced intraspecific variation, it is assumed that the species of the C. succinctus group are either species in statu nascendi or very young species. Therefore, it remains important to include ecological data in species identification.

An estimated 50% decline in Taiga Bean Geese A. fabalis between the mid-1990s and 2015 contrasted increasing numbers of Tundra Bean Goose A. serrirostris wintering in Western Europe at the same time. Seber dead-recovery analysis of metal-ringed individuals used to investigate year- and age effects on survival estimates from historical ringing data of both taxa caught in The Netherlands 1964–1987 generated annual survival rates of 0.716 (0.013 SE) and 0.803 (0.007) for A. fabalis and 0.824 (0.006) and 0.831 (0.005) for A. serrirostris for first-winter and adults, respectively.

Tumor budding is a long-established independent adverse prognostic marker in colorectal cancer, yet methods for its assessment have varied widely. In an effort to standardize its reporting, a group of experts met in Bern, Switzerland, in 2016 to reach consensus on a single, international, evidence-based method for tumor budding assessment and reporting (International Tumor Budding Consensus Conference [ITBCC]). Tumor budding assessment using the ITBCC criteria has been validated in large cohorts of cancer patients and incorporated into several international colorectal cancer pathology and clinical guidelines. With the wider reporting of tumor budding, new issues have emerged that require further clarification. To better inform researchers and health-care professionals on these issues, an international group of experts in gastrointestinal pathology participated in a modified Delphi process to generate consensus and highlight areas requiring further research. This effort serves to re-affirm the importance of tumor budding in colorectal cancer and support its continued use in routine clinical practice. Supplementary Information The online version contains supplementary material available at 10.1007/s00428-021-03059-9.

Supplemental Digital Content is available in the text., Rationale: Fibrosis promotes the maintenance of atrial fibrillation (AF), making it resistant to therapy. Improved understanding of the molecular mechanisms leading to atrial fibrosis will open new pathways toward effective antifibrotic therapies. Objective: This study aims to decipher the mechanistic interplay between PLK2 (polo-like kinase 2) and the profibrotic cytokine OPN (osteopontin) in the pathogenesis of atrial fibrosis and AF. Methods and Results: Atrial PLK2 mRNA expression was 10-fold higher in human fibroblasts than in cardiomyocytes. Compared with sinus rhythm, right atrial appendages and isolated right atrial fibroblasts from patients with AF showed downregulation of PLK2 mRNA and protein, along with increased PLK2 promotor methylation. Genetic deletion as well as pharmacological inhibition of PLK2 induced profibrotic phenotype conversion in cardiac fibroblasts and led to a striking de novo secretion of OPN. Accordingly, PLK2-deficient (PLK2 knockout) mice showed cardiac fibrosis and were prone to experimentally induced AF. In line with these findings, OPN plasma levels were significantly higher only in patients with AF with atrial low-voltage zones (surrogates of fibrosis) compared with sinus rhythm controls. Mechanistically, we identified ERK1/2 as the relevant downstream mediator of PLK2 leading to increased OPN expression. Finally, oral treatment with the clinically available drug mesalazine, known to inhibit ERK1/2, prevented cardiac OPN overexpression and reversed the pathological PLK2 knockout phenotype in PLK2 knockout mice. Conclusions: Abnormal PLK2/ERK1/2/OPN axis function critically contributes to AF-related atrial fibrosis, suggesting reinforcing PLK2 activity and/or OPN inhibition as innovative targets to prevent fibrosis progression in AF. Mesalazine derivatives may be used as lead compounds for the development of novel anti-AF agents targeting fibrosis.

The adult brain retains endogenous neural stem/precursors cells (eNPCs) in two major neurogenic niches, the subgranular zone (SGZ) in the hippocampus and the subventricular zone (SVZ). While in humans and rodents the SGZ contributes to memory functions by generating new neurons that integrate into hippocampal circuitry, the role of eNPCs of the SVZ is less clear. SVZ-eNPCs contribute to the generation of new neurons fated to the olfactory bulb (OB) in rodents but not in humans where they are thought to contribute to striatal neurogenesis as a result of tissue damage.Here, we show in mice and humans a novel non-neurogenic physiological role of adult SVZ-eNPCs in supporting cognitive functions by regulating striatal neuronal activity. We first provide evidence that GABAergic transmission between parvalbumin-expressing fast-spiking interneurons (FSIs) and medium spiny neurons (MSNs) is tuned by SVZ-eNPCs via secretion of Insulin-Like Growth Factor Binding Protein Like 1 (IGFBPL-1) that, in turn, regulates the Insulin-Like Growth Factor (IGF-1) signalling cascade. Consistently, selective ablation of SVZ-eNPCs and in vivo disruption of the IGF-signalling determine the impairment of intrastriatal coherence. A finding associated with a higher failure rate of GABAergic transmission mediated by FSIs and with striatum-related behavioural dysfunctions impairing decision making. Human validation studies revealed IGFBPL-1 expression in the SVZ and in foetal and induced-pluripotent stem cell-derived NPCs as well as a strong correlation in neurological patients between SVZ pathological damage, reduction of striatum volume and impairment of information processing speed.All in all, our results highlight a novel non-neurogenic homeostatic role exerted by SVZ-eNPCs on striatal GABAergic neurons that might contribute to cognitive processes involving decisions-making tasks.

Background Cartilage shortage is a major problem in facial reconstructive surgery. Prior studies have shown that decellularized porcine nasal septal cartilage (DPNC) seeded with primary human nasal chondrocytes enabled cartilage regeneration and showed potential as a replacement material for nasal cartilage. Since adipose tissue-derived stem cells (ASCs) are easily accessible and almost abundantly available, they appear to be a promising alternative to limited chondrocytes making the combination of DPNC and ASCs a feasible approach towards clinical translation. Thus, this study was intended to investigate the interactions between ASCs and DPNC in an in vitro model. Methods DPNCs were seeded and 3D-cultured with primary human ASCs that were priorly characterized with trilineage differentiation and flow cytometry. Cell vitality and proliferation were evaluated by Live-Dead, alamarBlue, and PicoGreen assays. Chondrogenic differentiation was examined by DMMB assay and cryosectioning-based histology. Cell invasion within DPNC was visualized and quantified by fluorescent histology (DAPI, Phalloidin). Results ASCs showed good adherence to DPNC and Live-Dead assay proved their viability over 2 weeks. AlamarBlueassay showed an increase in metabolic activity compared to 2D cultures, and PicoGreen assay demonstrated an increase of cell number within DPNC over time. Biochemical assays and histology added evidence of chondrogenic differentiation of 3D-cultured ASCs under the influence of chondrogenic induction medium. Fluorescent image analysis showed a significant increase of cell-occupied areas of scaffolds over time (P Conclusions DPNC scaffolds provided a suitable environment for ASCs that allowed good cell vitality, high proliferation, and chondrogenic differentiation. Thus, the use of ASCs and DPNC yields a promising alternative to the use of primary human chondrocytes. For facial cartilage tissue engineering, we regard ASCs as an attractive alternative to human nasal chondrocytes due to their better accessibility and availability. Further research will be necessary to determine long-term effects and in vivo outcomes of ASCs and DPNC in cartilage regeneration of the face.

There is a growing appreciation that insect distribution and abundance are associated with the limits of thermal tolerance, but the physiology underlying thermal tolerance remains poorly understood. Many insects, like the migratory locust (Locusta migratoria), suffer a loss of ion and water balance leading to hyperkalaemia (high extracellular [K+]) in the cold that indirectly causes cell death. Cells can die in several ways under stress, and how they die is of critical importance to identifying and understanding the nature of thermal adaptation. Whether apoptotic or necrotic cell death pathways are responsible for low-temperature injury is unclear. Here, we use a caspase-3 specific assay to indirectly quantify apoptotic cell death in three locust tissues (muscle, nerves and midgut) following prolonged chilling and recovery from an injury-inducing cold exposure. Furthermore, we obtain matching measurements of injury, extracellular [K+] and muscle caspase-3 activity in individual locusts to gain further insight into the mechanistic nature of chilling injury. We found a significant increase in muscle caspase-3 activity, but no such increase was observed in either nervous or gut tissue from the same animals, suggesting that chill injury primarily relates to muscle cell death. Levels of chilling injury measured at the whole animal level, however, were strongly correlated with the degree of haemolymph hyperkalaemia, and not apoptosis. These results support the notion that cold-induced ion balance disruption triggers cell death but also that apoptosis is not the main form of cell damage driving low-temperature injury.

Morocco is a well known hot-spot of biodiversity in the Mediterranean basin. While some taxa like vascular plants are relatively well recorded, important groups of pollinators like bees are still understudied. This article presents an updated checklist of the bee species of Morocco and includes a summary of global and regional distribution of each species. A total of 961 species belonging to six bee families and 68 genera are recorded: Andrenidae (8 genera, 217 species); Apidae (15 genera, 241 species); Colletidae (2 genera, 74 species), Halictidae (12 genera, 144 species), Megachilidae (28 genera, 271 species) and Melittidae (3 genera, 14 species). Among them, 67 species are recorded for the first time in Morocco. Around 70% of the bee fauna of Morocco consists of widespread Palaearctic species. Only 18% of Moroccan species recorded are restricted to North Africa and 8% are Moroccan single-country endemics (81 species). Afrotropical elements in the Moroccan fauna are few, with only 3% of Morocco species co-occuring in that region. This checklist is intended to stimulate new regional research on bees including their taxonomy and biogeography. As many groups of bees have been understudied, discovery of new species for science and new records for the country can be expected. Additional research including inventorying, monitoring, and integrative taxonomic studies are needed to develop a comprehensive strategy for bee conservation in Morocco.