Different Lines Of Evidence Research Articles

The function and flexible use of a Neolithic microlithic assemblage from the Huihe dam site, Inner Mongolia: a quantifiable analysis of use-wear evidence

Microblade technology played a key role in the everyday lives of the occupants of Inner Mongolia during the Neolithic period. However, the functional aspect of the microblade assemblage and its role had not been widely studied. In order to better understand the occupants’ daily life and toolkit management within this context, the current study conducted use-wear analyses on a large sample of lithic tools from a Neolithic microlithic assemblage found at the Huihe dam site and then addressed the implication of the results by integrating different lines of evidence from morphological, technological, and functional aspects through quantifiable analysis. Our study supports the site as a base camp where a wide range of activities were carried out. The results of the study also showed that it is highly probable that the intensive and flexible use of the microblade assemblage contributed to a sustainable hunter-gatherer lifestyle over a long period.

Surprising similarities in model and observational aerosol radiative forcing estimates.

The radiative forcing from aerosols (particularly through their interaction with clouds) remains one of the most uncertain components of the human forcing of the climate. Observation-based studies have typically found a smaller aerosol effective radiative forcing than in model simulations and were given preferential weighting in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). With their own sources of uncertainty, it is not clear that observation-based estimates are more reliable. Understanding the source of the model and observational differences is thus vital to reduce uncertainty in the impact of aerosols on the climate.These reported discrepancies arise from the different methods of separating the components of aerosol forcing used in model and observational studies. Applying the observational decomposition to global climate model (GCM) output, the two different lines of evidence are surprisingly similar, with a much better agreement on the magnitude of aerosol impacts on cloud properties. Cloud adjustments remain a significant source of uncertainty, particularly for ice clouds. However, they are consistent with the uncertainty from observation-based methods, with the liquid water path adjustment usually enhancing the Twomey effect by less than 50%. Depending on different sets of assumptions, this work suggests that model and observation-based estimates could be more equally weighted in future synthesis studies.

Early Molecular Dialogue Between Legumes and Rhizobia: Why Are They So Important?

Legume-rhizobia symbiosis has a considerable ecological relevance because it replenishes the soil with fixed-nitrogen (e.g., ammonium) for other plants. Because of this benefit to the environment, the exploitation of the legume-rhizobia symbiosis can contribute to the development of the lower input, sustainable agriculture, thereby, reducing dependency on synthetic fertilizers. To achieve this goal, it is necessary to understand the different levels of regulation of this symbiosis to enhance its nitrogen-fixation efficiency. A different line of evidence attests to the relevance of early molecular events in the establishment of a successful symbiosis between legumes and rhizobia. In this chapter, we will review the early molecular signaling in the legume-rhizobia symbiosis. We will focus on the early molecular responses that are crucial for the recognition of the rhizobia as a potential symbiont.

GABRB2 in Neuropsychiatric Disorders: Genetic Associations and Functional Evidences

Background: The inhibitory GABAergic system has shown an association with multiple psychiatric disorders. The type A GABA receptors are an integral component of this system, and in recent years, evidence has accumulated to support an essential role in disease etiology for one of the receptor genes GABRB2 which encodes for the receptor β2 subunit. Objective: To summarize the different lines of evidence supporting the important role of GABRB2 in psychiatric disorders, with a particular focus on schizophrenia, and evaluate the recently-proposed GABRB2-origin of schizophrenia hypothesis. Results: In terms of genetics, Single Nucleotide Polymorphisms (SNPs) in GABRB2 have been associated with a number of psychiatric disorders, and some of the associations have remained significant following meta-analysis. Importantly, expression and alternative splicing of the gene was shown to be dependent on the genotypes of the associated SNPs, and receptors containing the long isoform displayed functional differences compared to those containing the short isoform. Moreover, differential epigenetic regulation and imprinting imbalance of the gene were observed in schizophrenic patients compared to healthy subjects. Finally, recent findings from a Gabrb2-knockout mouse model demonstrated that knockout of the gene alone was sufficient to induce a wide range of schizophrenia- like symptoms and comorbid phenotypes. Conclusion: The different lines of evidence coalesce to strongly support the recentlyproposed GABRB2-origin of schizophrenia hypothesis, and GABRB2 may also have a potential role in cognition, the dysfunction of which is common to many psychiatric disorders.

Too strict or too loose? Integrative taxonomic assessment of Bombus lapidarius complex (Hymenoptera: Apidae)

AbstractThe latest progress of the taxonomy is the use of integrative approach for species delimitation based on a multisource dataset. However, the taxonomic decision that should be made when convergence between the different lines of evidence is not observed remains debated. Here, we investigate the consequences of the application of an ‘integration by cumulation’ approach on the taxonomic statuses within the Bombus lapidarius complex when using an integrative taxonomic framework (i.e. nuclear and mitochondrial markers along with reproductive traits) compared with a strict ‘integration by congruence’ method. Our results show similar taxonomic conclusions whatever the decision‐making approach used except for one taxon. According to the differentiation observed in our integrative taxonomic framework, recent divergence time and other field observations for this taxon, we assume that a too strict decision‐making method could fail to detect recently diverged species. This is exemplified by the new species Bombus bisiculus sp. n. occurring in South Italy and Sicily.

Form and function of tentacles in pteriomorphian bivalves.

Tentacles are remarkable anatomical structures in invertebrates for their diversity of form and function. In bivalves, tentacular organs are commonly associated with protective, secretory, and sensory roles. However, anatomical details are available for only a few species, rendering the diversity and evolution of bivalve tentacles still obscure. In Pteriomorphia, a clade including oysters, scallops, pearl oysters, and relatives, tentacles are abundant and diverse. We investigated tentacle anatomy in the group to understand variation, infer functions, and investigate patterns in tentacle diversity. Six species from four pteriomorphian families (Ostreidae, Pinnidae, Pteriidae, and Spondylidae) were collected and thoroughly investigated with integrative microscopy techniques, including histology, scanning electron microscopy, and confocal microscopy. Tentacles can be classified as middle fold tentacles (MFT) and inner fold tentacles (IFT) according to their position with respect to the folds of the mantle margin. While MFT morphology indicates intense secretion of mucosubstances, no evidence for secretory activity was found for IFT. However, both tentacle types have appropriate ciliary distribution and length to promote mucus transportation for cleaning and lubrication. Protective and sensory functions are discussed based on different lines of evidence, including secretion, cilia distribution, musculature, and innervation. Our results support the homology of MFT and IFT only for Pterioidea and Ostreoidea, considering their morphology, the presence of ciliated receptors at the tips, and branched innervation pattern. This is in accordance with recent phylogenetic hypotheses that support the close relationship between these superfamilies. In contrast, major structural differences indicate that MFT and IFT are probably not homologous across all pteriomorphians. By applying integrative microscopy, we were able to reveal anatomical elements that are essential for the understanding of homology and function when dealing with such superficially similar structures.

The palaeobiology of belemnites - foundation for the interpretation of rostrum geochemistry.

Belemnites are an extinct group of Mesozoic coleoid cephalopods with a fossil record ranging from the early Late Triassic [about 240 million years ago (Mya)] to the Cretaceous/Palaeogene boundary (65 Mya). Belemnites were widely distributed, highly abundant and diverse, and an important component of Mesozoic marine food webs. Their internal shells, specifically their low-Mg calcite rostra, have been used as palaeoenvironmental carbonate archives for the last 70 years. This is primarily due to the assumption that the rostrum calcite formed in equilibrium with the oxygen isotope composition of ambient sea water. Of prime importance for the reliable interpretation of isotope data derived from these biogenic carbonates is a robust reconstruction of the palaeobiology of their producers. Here we provide a critical assessment of published reconstructions of belemnite soft-body organization and their lifestyle and habitats. Different lines of evidence, including sedimentological, geochemical, morphological, and biomechanical data, point towards an outer shelf habitat of belemnites, for some taxa also including the littoral area. Belemnite habitat temperatures, oxygen content, salinities, and life span are constrained based on observations of the ecology and life history of modern coleoids. Belemnite habitat depth might have been largely controlled by food and temperature, with a temperature optimum between 10°C and 30°C. The distribution of modern coleoids is for most species restricted to well-oxygenated water masses and a salinity between 27 and 37 psu. The trophic position of belemnites as both predators and prey is documented by unique fossil finds of stomach contents and soft tissue preservation, such as jaws, hooks, and ink sacs. Belemnites were medium-sized predators in the epipelagic zone (not deeper than ∼200 m) hunting for crustaceans, other cephalopods, and fishes. Taxa with elongated rostra probably were fast and highly manoeuvrable swimmers. Forms with conical rostra represent slow but highly manoeuvrable swimmers, and forms with depressed rostra likely had a bottom-related life habit. Predators of adult belemnites were sharks, bony fishes, and marine reptiles. Belemnites, like most of the modern coleoids, were relatively short lived, most likely living only for 1-2 years. Understanding the biomineralization of belemnite rostra is highly relevant for an improved interpretation of their geochemistry. Here we confirm that belemnite rostra are composed of low Mg-calcite fibres, but they do not contain distinct types of laminae. These fibres are composed of two distinct calcite phases. One phase is a filigree network of tetrahedral organic-rich calcite and the second phase is represented by organic-poor calcite.

New observations on high‐pressure phases in a shock melt vein in the Villalbeto de la Peña meteorite: Insights into the shock behavior of diopside

AbstractThe petrology and mineralogy of shock melt veins in the L6 ordinary chondrite host of Villalbeto de la Peña, a highly shocked, L chondrite polymict breccia, have been investigated in detail using scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and electron probe microanalysis. Entrained olivine, enstatite, diopside, and plagioclase are transformed into ringwoodite, low‐Ca majorite, high‐Ca majorite, and an assemblage of jadeite‐lingunite, respectively, in several shock melt veins and pockets. We have focused on the shock behavior of diopside in a particularly large shock melt vein (10 mm long and up to 4 mm wide) in order to provide additional insights into its high‐pressure polymorphic phase transformation mechanisms. We report the first evidence of diopside undergoing shock‐induced melting, and the occurrence of natural Ca‐majorite formed by solid‐state transformation from diopside. Magnesiowüstite has also been found as veins injected into diopside in the form of nanocrystalline grains that crystallized from a melt and also occurs interstitially between majorite‐pyrope grains in the melt‐vein matrix. In addition, we have observed compositional zoning in majorite‐pyrope grains in the matrix of the shock‐melt vein, which has not been described previously in any shocked meteorite. Collectively, all these different lines of evidence are suggestive of a major shock event with high cooling rates. The minimum peak shock conditions are difficult to constrain, because of the uncertainties in applying experimentally determined high‐pressure phase equilibria to complex natural systems. However, our results suggest that conditions between 16 and 28 GPa and 2000–2200 °C were reached.

Recent advances in amniote palaeocolour reconstruction and a framework for future research.

ABSTRACTPreserved melanin pigments have been discovered in fossilised integumentary appendages of several amniote lineages (fishes, frogs, snakes, marine reptiles, non‐avialan dinosaurs, birds, and mammals) excavated from lagerstätten across the globe. Melanisation is a leading factor in organic integument preservation in these fossils. Melanin in extant vertebrates is typically stored in rod‐ to sphere‐shaped, lysosome‐derived, membrane‐bound vesicles called melanosomes. Black, dark brown, and grey colours are produced by eumelanin, and reddish‐brown colours are produced by phaeomelanin. Specific morphotypes and nanostructural arrangements of melanosomes and their relation to the keratin matrix in integumentary appendages create the so‐called 'structural colours'. Reconstruction of colour patterns in ancient animals has opened an exciting new avenue for studying their life, behaviour and ecology. Modern relationships between the shape, arrangement, and size of avian melanosomes, melanin chemistry, and feather colour have been applied to reconstruct the hues and colour patterns of isolated feathers and plumages of the dinosaurs Anchiornis, Sinosauropteryx, and Microraptor in seminal papers that initiated the field of palaeocolour reconstruction. Since then, further research has identified countershading camouflage patterns, and informed subsequent predictions on the ecology and behaviour of these extinct animals. However, palaeocolour reconstruction remains a nascent field, and current approaches have considerable potential for further refinement, standardisation, and expansion. This includes detailed study of non‐melanic pigments that might be preserved in fossilised integuments. A common issue among existing palaeocolour studies is the lack of contextualisation of different lines of evidence and the wide variety of techniques currently employed. To that end, this review focused on fossil amniotes: (i) produces an overarching framework that appropriately reconstructs palaeocolour by accounting for the chemical signatures of various pigments, morphology and local arrangement of pigment‐bearing vesicles, pigment concentration, macroscopic colour patterns, and taphonomy; (ii) provides background context for the evolution of colour‐producing mechanisms; and (iii) encourages future efforts in palaeocolour reconstructions particularly of less‐studied groups such as non‐dinosaur archosaurs and non‐archosaur amniotes.

Arqueología del Bajo y Medio río Magdalena: apuntes sobre procesos de poblamiento prehispánico de las Tierras Bajas tropicales interandinas de Colombia

En este artículo se dan a conocer datos e interpretaciones arqueológicas basados en más de cincuenta años de investigaciones realizadas en el valle del Río Magdalena en Colombia. Nuestro objetivo es describir sus principales características fisiográficas, revelar cambios experimentados en el paisaje y plantear aspectos destacados de las estrategias adaptativas, modos de vida y organización social durante distintos periodos. Se priorizaron las dinámicas de cambio cultural en las tierras bajas de los sectores Bajo y Medio Magdalena, a partir de una síntesis sobre aspectos relacionados con la tecnología lítica y cerámica, las prácticas funerarias y la cronología en un marco temporal amplio desde el final del Pleistoceno al Holoceno tardío. Se trata de una reflexión que recoge resultados de estudios anteriores del autor y de quienes han contribuido al desarrollo de la arqueología del valle del Magdalena y se plantean preguntas de investigación a largo plazo, con la pretención de integrar distintas líneas de evidencia, en particular desde la geoarqueología, interrogándose sobre si es posible proponer modelos para adelantar explicaciones de la presencia o no, y el tipo de evidencias arqueológicas. Surgen consideraciones sobre la existencia ?dispersa? de vestigios de alta calidad tecnológica y estilística relacionados con asentamientos denominados ?formativos? o contextos ?clásicos?, caracterizados por conjuntos de cerámica y orfebrería sobresalientes, con cronologías entre 2800AP a 1400AP. Actualmente estas evidencias presentan discontinuidad en el paisaje a lo largo del valle. Al contrario, las relativamente menos elaboradas realizaciones tardías ?enmarcadas en el denominado ?Horizonte de Urnas Funerarias? del Magdalena?, muestran recurrencia en vegas, terrazas recientes y colinas, y demuestran ocupaciones en el último milenio AP, incluyendo los contactos con los europeos desde el Siglo XVI.

Species delimitation and phylogeography of Abies delavayi complex: Inferred from morphological, molecular, and climatic data

AbstractThe species delimitation within Abies delavayi complex, consisting of A. delavayi Franch., A. fabri (Mast.) Craib, A. nukiangensis W. C. Cheng & L. K. Fu, and A. delavayi subsp. fansipanensis (Q. P. Xiang, L. K. Fu & Nan Li) Rushforth, has been a subject of long‐term dispute. We combined different lines of evidence, including morphological characters, population‐based mitochondrial DNA and chloroplast DNA sequences, and plastome data to assess its species delimitation. These four independent datasets revealed a consistent result that the four taxa of A. delavayi complex were hardly separated and could be regarded as one species. Our results further suggested that these four taxa might have experienced rapid morphological diversification, following a common expansion triggered by climate oscillations during the Pleistocene. In addition, we surveyed the phylogeographical history of A. delavayi complex as a whole based on ecological niche models and molecular data. These results consistently revealed that this high‐mountain fir complex had experienced glacial expansion and interglacial contraction. Therefore, we propose that A. delavayi complex probably has undergone the phalanx expansion model in response to climate change during the Quaternary. Such expansion patterns demand consideration when establishing conservation strategies for threatened fir species.

Towards a better understanding of the association between motor skills and executive functions in 5- to 6-year-olds: The impact of motor task difficulty

Different lines of evidence suggest an association between motor skills and executive functions (EFs) in kindergarten children. Comparatively little is known about the specific nature of this relationship. In the present study, using a within-subjects design, a sample of 124 five- to six-year-old children completed 12 fine and gross motor tasks of varying nominal difficulty and three EFs tasks. We assumed that difficult motor tasks are less automated than easy motor tasks. Therefore, EFs should be involved more strongly in difficult compared to easy motor tasks. Firstly, results replicated the association between motor skills and EFs. Secondly, results provided a new and differentiated perspective on the evidence of this link. Performance on both easy and difficult fine motor tasks was significantly related to EFs. However, only performance on the difficult, but not on the easy gross motor tasks was significantly correlated with EFs. The findings demonstrate that the challenges and demands inherent in any motor task influence the magnitude of the motor–EFs link. That is, difficult (i.e., less automated) motor tasks require EFs more substantially than easy (i.e., more automated) motor tasks. Results will be discussed with regard to further candidate processes underlying the motor–EFs link.

Transforming landscapes: Modeling land-use patterns of environmental borderlands

How did socio-cultural transformation processes change land-use patterns? Throughout the last 50 years, outstanding comprehensive geographic, archaeobiological, and archaeological data have been produced for the area of Oldenburger Graben, Schleswig-Holstein, Germany. Based on this exceptional data set, we are able to study the land-use patterns for a period ranging from the Final Mesolithic until the Late Neolithic (4600–1700 BCE). By application of fuzzy modeling techniques, these patterns are investigated diachronically in order to assess the scale of transformations between the different archaeological phases. Based on nutrient requirements and proposed dietary composition estimates derived from empirical archaeobotanical, archaeozoological, and stable isotope data, the required extent of the areas for different land-use practices are modeled. This information is made spatially explicit using a fuzzy model that reconstructs areas of potential vegetation and land-use for each transformation phase. Pollen data are used to validate the type and extent of land-use categories. The model results are used to test hypotheses on the dynamics of socio-cultural transformations: can we observe a diversification of land-use patterns over time or does continuity of land-use practices prevail? By integrating the different lines of evidence within a spatially explicit modeling approach, we reach a new quality of data analysis with a high degree of contextualization. This allows testing of hypotheses about Neolithic transformation processes by an explicit adjustment of our model assumptions, variables, and parameters.

Behavioral adaptations of sandy beach macrofauna in face of climate change impacts: A conceptual framework

Sandy beaches are severely under-represented in the literature on climate-change ecology, yet different lines of evidence suggest that the macrofauna inhabiting these narrow and dynamic environments located at the land-sea interface is being reorganized under the influence of this large scale and long-lasting stressor. This is reflected in macrofaunal sensitivity to increasing sea surface temperature, sea-level rise, extreme events and erosion of the narrow physical habitat. However, evidence of behavioral responses by sandy beach macrofauna that are consistent with expectations under climate change is scarce and fragmentary. In this paper, specific hypotheses are formulated for how behavioral adaptations in sandy beach macrofauna are predicted to respond to climate change impacts. Firstly, a conceptual framework and an overview of macrofauna behavioral adaptation features are provided. Secondly, the effects of main climate change drivers on sandy beaches are summarized. Thirdly, a conceptual framework is developed giving behavioral adaptations of sandy beach macrofauna under climate change pressure. The degree to which observations on behavioral adaptations of beach animals conform to expectations under specific climate change drivers (sea level rise, sea surface temperature, winds and storminess, rainfall, acidification and eutrophication) is explored. Taking into account the empirical evidence and the theoretical framework detailed in the paper, emergent hypotheses/predictions are proposed. Climate change drivers are expected to impact habitat features and consequently the behavioral expression of macrofauna as active responses to habitat changes. Behavioral adaptations are expected to be impaired, more variable or disrupted, thus decreasing fitness, causing local population extirpations and potentially triggering a range of cascading effects of ecological change in the beach ecosystem. Biodiversity loss will be the outcome of the negative pressures driven by climate change. The specificity of sandy beaches as narrow ecotones between sea and land may be lost under climate change pressure, adversely affecting fine-tuned macrofaunal adaptations and therefore ecosystem functioning. Strictly adapted endemic sandy beach fauna will be especially subjected to local extirpations, while species with a large reaction norm (i.e. phenotypic and behavioral plasticity) may face changes by dispersal and exploitation of new niches. Under climate change impacts, biodiversity loss is predicted, which would hamper beach ecosystem resilience. The limits to which sandy beach macrofauna responds and can behaviorally adapt to environmental change are worthy of exploration, in view of the increasing influence of the long-lasting climate driven stressors threatening these ecosystems at risk.

Neurobiological effects of aerobic exercise, with a focus on patients with schizophrenia.

Schizophrenia is a severe neuropsychiatric disease that is associated with neurobiological alterations in multiple brain regions and peripheral organs. Negative symptoms and cognitive deficits are present in about half of patients and are difficult to treat, leading to an unfavorable functional outcome. To investigate the impact of aerobic exercise on various neurobiological parameters, we conducted a narrative review. Add-on aerobic exercise was shown to be effective in improving negative and general symptoms, cognition, global functioning, and quality of life in schizophrenia patients. Based on findings in healthy individuals and animal models, this qualitative review gives an overview of different lines of evidence on how aerobic exercise impacts brain structure and function and molecular mechanisms in patients with schizophrenia and how its effects could be related to clinical and functional outcomes. Structural magnetic resonance imaging studies showed a volume increase in the hippocampus and cortical regions in schizophrenia patients and healthy controls after endurance training. However, results are inconsistent and individual risk factors may influence neuroplastic processes. Animal studies indicate that alterations in epigenetic mechanisms and synaptic plasticity are possible underlying mechanisms, but that differentiation of glial cells, angiogenesis, and possibly neurogenesis may also be involved. Clinical and animal studies also revealed effects of aerobic exercise on the hypothalamus-pituitary-adrenal axis, growth factors, and immune-related mechanisms. Some findings indicate effects on neurotransmitters and the endocannabinoid system. Further research is required to clarify how individual risk factors in schizophrenia patients mediate or moderate the neurobiological effects of exercise on brain and cognition. Altogether, aerobic exercise is a promising candidate in the search for pathophysiology-based add-on interventions in schizophrenia.

Environmental cadmium exposure and pancreatic cancer: Evidence from case control, animal and in vitro studies

Although profoundly studied, etiology of pancreatic cancer (PC) is still rather scarce. Some of established risk factors of PC are connected to an increased cadmium (Cd) body burden. Hence, the aim of this study was to investigate the role of this environmental pollutant in PC development by conducting human observational, experimental and in vitro studies.The case-control study included 31 patients with a histologically based diagnosis of exocrine PC subjected to radical surgical intervention as cases and 29 accidental fatalities or subjects who died of a nonmalignant illness as controls. Animal study included two treated groups of Wistar rats (15 and 30 mg Cd/kg b.w) and untreated control group, sacrificed 24 h after single oral exposure. In in vitro study pancreas hTERT-HPNE and AsPC-1 cells were exposed to different Cd concentrations corresponding to levels measured in human cancerous pancreatic tissue.Cd content in cancer tissue significantly differed from the content in healthy controls. Odds ratio levels for PC development were 2.79 (95% CI 0.91–8.50) and 3.44 (95% CI 1.19–9.95) in the third and fourth quartiles of Cd distribution, respectively. Animal study confirmed Cd deposition in pancreatic tissue. In vitro studies revealed that Cd produces disturbances in intrinsic pathway of apoptotic activity and the elevation in oxidative stress in pancreatic cells.This study presents three different lines of evidence pointing towards Cd as an agent responsible for the development of PC.

A new widespread subclass of carbonic anhydrase in marine phytoplankton

Most aquatic photoautotrophs depend on CO2-concentrating mechanisms (CCMs) to maintain productivity at ambient concentrations of CO2, and carbonic anhydrase (CA) plays a key role in these processes. Here we present different lines of evidence showing that the protein LCIP63, identified in the marine diatom Thalassiosira pseudonana, is a CA. However, sequence analysis showed that it has a low identity with any known CA and therefore belongs to a new subclass that we designate as iota-CA. Moreover, LCIP63 unusually prefers Mn2+ to Zn2+ as a cofactor, which is potentially of ecological relevance since Mn2+ is more abundant than Zn2+ in the ocean. LCIP63 is located in the chloroplast and only expressed at low concentrations of CO2. When overexpressed using biolistic transformation, the rate of photosynthesis at limiting concentrations of dissolved inorganic carbon increased, confirming its role in the CCM. LCIP63 homologs are present in the five other sequenced diatoms and in other algae, bacteria, and archaea. Thus LCIP63 is phylogenetically widespread but overlooked. Analysis of the Tara Oceans database confirmed this and showed that LCIP63 is widely distributed in marine environments and is therefore likely to play an important role in global biogeochemical carbon cycling.

Pleistocene extinctions as drivers of biogeographical patterns on the easternmost Canary Islands

AbstractSubtropical islands are often viewed as refuges where Quaternary climatic shifts driving global episodes of extinction were buffered. Island biodiversity, however, may have been impacted by climatic fluctuations at local scales, particularly in spatially heterogeneous island systems. In this study, we generated a conceptual framework for predicting the potential impact of Pleistocene extinctions on the biogeographical pattern of the Canarian spermatophyte flora, with a focus on the easternmost Canarian islands (ECI). Then, we performed an exhaustive bibliographic revision (270 studies) to examine whether taxonomic, phylogenetic and phylogeographical data support our predictions. Although molecular information is limited for many lineages, the available data suggest that the majority of extant ECI plant taxa may be the result of relatively recent (<1 Ma) dispersal from surrounding insular and mainland areas. Different lines of evidence are compatible with the idea of a Pleistocene period of frequent lineage extirpation on ECI. Extinction may thus have provided new ecological opportunities for recent (re)colonization, with some cases of recent establishment mediated by facilitation. Considering background extinction on ECI, we describe five general patterns of colonization for Canarian plant lineages. In addition to factors related to island ontogeny and long‐distance dispersal, we suggest that Pleistocene extinctions may have significantly contributed to extant biogeographical patterns in the Canarian archipelago, such as the biased distribution ranges of island plants and the low endemic richness on ECI. This new scenario provides testable hypotheses for future studies dealing with the phylogeography, taxonomy and conservation of terrestrial biodiversity on the Canarian islands, and possibly, on other near‐shore islands.

Genetic Aspects of Latent Autoimmune Diabetes in Adults: A Mini-Review.

Diabetes is a multifactorial disease, caused by a complex interplay between environmental and genetic risk factors. Genetic determinants of particularly Type 1 Diabetes (T1D) and Type 2 Diabetes (T2D) have been studied extensively, whereas well-powered studies of Latent Autoimmune Diabetes in Adults (LADA) are lacking. So far available studies support a clear genetic overlap between LADA and T1D, however, with smaller effect sizes of the T1D-risk variants in LADA as compared to T1D. A genetic overlap between LADA and T2D is less clear. However, recent studies, including large numbers of LADA patients, provide different lines of evidence to support a genetic overlap between T2D and LADA. The genetic predisposition to LADA is yet to be explored in a study design, like a genome- wide association study, which allows for analyses of the genetic predisposition independently of prior hypothesis about potential candidate genes. This type of study may facilitate the discovery of risk variants associated with LADA independently of T1D and T2D, and is central in order to determine if LADA should be considered as an independent diabetic subtype. Extended knowledge about the genetic predisposition to LADA may also facilitate stratification of the heterogeneous group of LADA patients, which may assist the choice of treatment. This mini-review summarizes current knowledge of the genetics of LADA, and discusses the perspectives for future studies.

A comparative study of the proteome regulated by the Rpb4 and Rpb7 subunits of RNA polymerase II in fission yeast

RNA polymerase II is a conserved multi-subunit enzyme made up of twelve different subunits. Two of these subunits, Rpb4 and Rpb7, have been shown to perform functions in both transcription as well as outside of transcription in Saccharomyces cerevisiae. However, our knowledge about the roles of these subunits in Schizosaccharomyces pombe and higher eukaryotes is still limited. Moreover, both Rpb4 and Rpb7 are indispensable for viability of S. pombe and higher eukaryotes, in comparison to S. cerevisiae where deletion of only Rpb7 results in lethality. Therefore in this study, we used S. pombe strains expressing reduced levels of these subunits to determine their impact on the S. pombe proteome employing i–TRAQ based proteomics approach. Furthermore, proteomic profiling was carried out at two different time points to gain a temporal insight into the processes regulated by Rpb4 and Rpb7. The results showed that reduced levels of either Rpb4 or Rpb7 affected the expression of proteins involved in metabolism and ribosome biogenesis at both the time points. Our polysomal profiling experiments further revealed a role of these subunits in translation. Taken together, our results suggest a key role of Rpb4 and Rpb7 subunits in ribosome biogenesis and protein translation in S. pombe. SignificanceRpb4 and Rpb7 subunits of RNA polymerase II are known for their diverse roles in regulating transcription, mRNA export, mRNA decay, stress response and translation in S. cerevisiae. However, their roles in other organisms are yet to be characterized in detail. Different lines of evidence also suggest that these subunits may function independently as well as a complex in budding yeast. Therefore, in the present study we employed a genome-wide quantitative proteomics-based approach to gain deeper insights into their cellular roles, and to examine if they regulate similar or different biological pathways in fission yeast. Our results provide evidence that they are both involved in primarily regulating metabolic pathways and ribosome biogenesis and also, play a role in protein translation in S. pombe.