Normal radial migration and lamination are maintained in dyslexia-susceptibility candidate gene homolog Kiaa0319 knockout mice

AbstractDevelopmental dyslexia is a common disorder with a strong genetic component, but the underlying molecular mechanisms are still unknown. Several candidate dyslexia-susceptibility genes, including KIAA0319, DYX1C1, and DCDC2, have been identified in humans. RNA interference experiments targeting these genes in rat embryos have shown impairments in neuronal migration, suggesting that defects in radial cortical migration could be involved in the disease mechanism of dyslexia. Here we present the first characterisation of a Kiaa0319 knockout mouse line. Animals lacking KIAA0319 protein do not show anatomical abnormalities in any of the layered structures of the brain. Neurogenesis and radial migration of cortical projection neurons are not altered, and the intrinsic electrophysiological properties of Kiaa0319-deficient neurons do not differ from those of wild-type neurons. Kiaa0319 overexpression in cortex delays radial migration, but does not affect final neuronal position. However, knockout animals show subtle differences suggesting possible alterations in anxiety-related behaviour and in sensorimotor gating. Our results do not reveal a migration disorder in the mouse model, adding to the body of evidence available for Dcdc2 and Dyx1c1 that, unlike in the rat in utero knockdown models, the dyslexia-susceptibility candidate mouse homolog genes do not play an evident role in neuronal migration. However, KIAA0319 protein expression seems to be restricted to the brain, not only in early developmental stages but also in adult mice, indicative of a role of this protein in brain function. The constitutive and conditional knockout lines reported here will be useful tools for further functional analyses of Kiaa0319

Thermal conductivity measurements of macroscopic frozen salt ice analogues of Jovian icy moons in support of the planned JUICE mission

14 páginas, 16 figuras, 2 tablascThe study of thermal properties of frozen salt solutions representative of ice layers in Jovian moons is crucial to support the JUpiter ICy moons Explorer (JUICE) (ESA) and Europa Clipper (NASA) missions, which will be launched in the upcoming years to make detailed observations of the giant gaseous planet Jupiter and three of its largest moons (Ganymede, Europa, and Callisto), due to the scarcity of experimental measurements. Therefore, we have conducted a set of experiments to measure and study the thermal conductivity of macroscopic frozen salt solutions of particular interest in these regions, including sodium chloride (NaCl), magnesium sulphate (MgSO4 ), sodium sulphate (Na2 SO4 ), and magnesium chloride (MgCl2 ). Measurements were performed at atmospheric pressure and temperatures from 0 to −70 ◦C in a climatic chamber. Temperature and calorimetry were measured during the course of the experiments. An interesting side effect of these measurements is that they served to spot phase changes in the frozen salt solutions, even for very low salt concentrations. A small sample of the liquid salt-water solution was set aside for the calorimetry measurements. These experiments and the measurements of thermal conductivity and calorimetry will be valuable to constrain the chemical composition, physical state, and temperature of the icy crusts of Ganymede, Europa, and Callisto.This project received financial support of The European Space Agency (ESA) contracts No.: RFP/3-15589/18/ES/CM and 4000126441/19/ES/CM: ‘Measurements of thermal and dielectric properties of ices in support to future radar measurements of Jovian Icy moons’, The Unidad de Excelencia ‘Mar ́ıa de Maeztu’ MDM-2017-0737– Centro de Astrobiolog ́ıa (INTA-CSIC), The Spanish Ministry of Science, Innovation and Universities AYA2017-85322-R and PID2020-118974GB-C21 (AEI/FEDER, UE), Retos Investigaci ́on BIA2016-77992-R (AEI/FEDER, UE), and ‘Explora Ciencia y Explora Tecnolog ́ıa’ [AYA2017-91062- EXP]. We are grateful to Anezina Solomonidou for assistance in the project proposal. The view expressed in this article can in no way be taken to reflect the official opinion of the European Space Agency. We thank the reviewer of this article for his constructive comments.Peer reviewe

Naturalized alien flora of the world: species diversity, taxonomic and phylogenetic patterns, geographic distribution and global hotspots of plant invasion

Using the recently built Global Naturalized Alien Flora (GloNAF) database, containing data on the distribution of naturalized alien plants in 483 mainland and 361 island regions of the world, we describe patterns in diversity and geographic distribution of naturalized and invasive plant species, taxonomic, phylogenetic and life-history structure of the global naturalized flora as well as levels of naturalization and their determinants. The mainland regions with the highest numbers of naturalized aliens are some Australian states (with New South Wales being the richest on this continent) and several North American regions (of which California with 1753 naturalized plant species represents the world's richest region in terms of naturalized alien vascular plants). England, Japan, New Zealand and the Hawaiian archipelago harbour most naturalized plants among islands or island groups. These regions also form the main hotspots of the regional levels of naturalization, measured as the percentage of naturalized aliens in the total flora of the region. Such hotspots of relative naturalized species richness appear on both the western and eastern coasts of North America, in north-western Europe, South Africa, south-eastern Australia, New Zealand, and India. High levels of island invasions by naturalized plants are concentrated in the Pacific, but also occur on individual islands across all oceans. The numbers of naturalized species are closely correlated with those of native species, with a stronger correlation and steeper increase for islands than mainland regions, indicating a greater vulnerability of islands to invasion by species that become successfully naturalized. South Africa, India, California, Cuba, Florida, Queensland and Japan have the highest numbers of invasive species. Regions in temperate and tropical zonobiomes harbour in total 9036 and 6774 naturalized species, respectively, followed by 3280 species naturalized in the Mediterranean zonobiome, 3057 in the subtropical zonobiome and 321 in the Arctic. The New World is richer in naturalized alien plants, with 9905 species compared to 7923 recorded in the Old World. While isolation is the key factor driving the level of naturalization on islands, zonobiomes differing in climatic regimes, and socioeconomy represented by per capita GDP, are central for mainland regions. The 11 most widely distributed species each occur in regions covering about one third of the globe or more in terms of the number of regions where they are naturalized and at least 35% of the Earth's land surface in terms of those regions' areas, with the most widely distributed species Sonchus oleraceus occuring in 48% of the regions that cover 42% of the world area. Other widely distributed species are Ricinus communis, Oxalis corniculata, Portulaca oleracea, Eleusine indica, Chenopodium album, Capsella bursa-pastoris, Stellaria media, Bidens pilosa, Datura stramonium and Echinochloa crus-galli. Using the occurrence as invasive rather than only naturalized yields a different ranking, with Lantana camara (120 regions out of 349 for which data on invasive status are known), Calotropis procera (118), Eichhornia crassipes (113), Sonchus oleraceus (108) and Leucaena leucocephala (103) on top. As to the life-history spectra, islands harbour more naturalized woody species (34.4%) than mainland regions (29.5%), and fewer annual herbs (18.7% compared to 22.3%). Ranking families by their absolute numbers of naturalized species reveals that Compositae (1343 species), Poaceae (1267) and Leguminosae (1189) contribute most to the global naturalized alien flora. Some families are disproportionally represented by naturalized aliens on islands (Arecaceae, Araceae, Acanthaceae, Amaryllidaceae, Asparagaceae, Convolvulaceae, Rubiaceae, Malvaceae), and much fewer so on mainland (e.g. Brassicaceae, Caryophyllaceae, Boraginaceae). Relating the numbers of naturalized species in a family to its total global richness shows that some of the large species-rich families are over-represented among naturalized aliens (e.g. Poaceae, Leguminosae, Rosaceae, Amaranthaceae, Pinaceae), some under-represented (e.g. Euphorbiaceae, Rubiaceae), whereas the one richest in naturalized species, Compositae, reaches a value expected from its global species richness. Significant phylogenetic signal indicates that families with an increased potential of their species to naturalize are not distributed randomly on the evolutionary tree. Solanum (112 species), Euphorbia (108) and Carex (106) are the genera richest in terms of naturalized species; over-represented on islands are Cotoneaster, Juncus, Eucalyptus, Salix, Hypericum, Geranium and Persicaria, while those relatively richer in naturalized species on the mainland are Atriplex, Opuntia, Oenothera, Artemisia, Vicia, Galium and Rosa. The data presented in this paper also point to where information is lacking and set priorities for future data collection. The GloNAF database has potential for designing concerted action to fill such data gaps, and provide a basis for allocating resources most efficiently towards better understanding and management of plant invasions worldwide

Chemoprevention of Colonic Polyps with Balsalazide: An Exploratory, Double-Blind, Placebo-Controlled Study

A number of agents, including aspirin, nonsteroidal antiinflammatory drugs, cyclooxygenase-2 inhibitors, folic acid, calcium, and vitamins, have been evaluated for their potential in chemoprevention of sporadic colorectal adenomas or cancer. Preclinical data suggest that 5-aminosalicylates also may have a chemopreventive effect. To investigate chemoprevention of colonic polyps with balsalazide, a 5-aminosalicylate prodrug. In this randomized, double-blind, placebo-controlled study, adults diagnosed with small polyps in the rectosigmoid colon were treated with either balsalazide 3 g/d or placebo for 6 months. Follow-up lower endoscopy was performed, and all polyps were measured and analyzed histologically. The primary endpoint was reduction in mean size of the largest polyp per subject. Among 241 participants screened, 86 were randomized to treatment, with 75 subjects evaluable. Balsalazide 3 g/d (n = 38) did not significantly reduce the mean size of the largest colonic polyp or the number of polyps compared with placebo (n = 37). Although not significant, post-hoc analysis revealed that total adenoma burden per subject, calculated as the sum of the volumes of all adenomas in mm3, increased by 55% in the balsalazide group compared with 95% in the placebo group. Although balsalazide did not have significant chemopreventive effects on established colonic polyps, these results can aid in designing future prospective studies

Cost effectiveness of ulcerative colitis treatment in Germany: a comparison of two oral formulations of mesalazine

<p>Abstract</p> <p>Background</p> <p>The treatment of ulcerative colitis (UC) can place a substantial financial burden on healthcare systems. The anti-inflammatory compound 5-aminosalicylic acid (5-ASA; mesalazine) is the recommended first-line treatment for patients with UC. In this analysis, the incremental cost effectiveness ratio (ICER) of two oral formulations of 5-ASA (Mezavant^®and Asacol^®) is examined in the treatment of patients with mild-to-moderate, active UC in Germany.</p> <p>Methods</p> <p>A Markov cohort model was developed to assess the cost effectiveness of Mezavant compared with Asacol over a 5-year period in the German Statutory Health Insurance (SHI). Drug pricing details for 2009 were applied throughout the model, and overall resource use was determined and also fitted to 2009 from published results of a large cross sectional study of German SHI patients. Cost per quality adjusted life year (QALY) was the primary endpoint for this study. Remission rates were obtained using data from a randomised, phase III trial of Mezavant with an active Asacol reference arm and a long-term, open label, safety and tolerability trial of Mezavant. Uncertainty in the study model was assessed using one-way and probabilistic sensitivity analyses applying a Monte Carlo simulation.</p> <p>Results</p> <p>Over a 5-year period, healthcare costs for patients receiving Mezavant were 624 Euro lower than for patients receiving Asacol. Additionally, patients receiving Mezavant gained 0.011 QALYs or 18 more days in remission compared with Asacol. One-way sensitivity analyses suggest that these results are driven by both differences in the acquisition cost between mesalazine formulations and differences in treatment efficacy. Furthermore, sensitivity analyses suggest a probability of 76% for cost savings and higher QALYs with Mezavant compared with Asacol. If adherence and its influence on the remission rates and the risk of developing colorectal cancer were included in the model, the results might have even been more favorable to Mezavant due to its once daily dosing regimen.</p> <p>Conclusions</p> <p>This model suggests that patients treated with Mezavant may achieve increased time in remission and higher QALYs, with lower direct costs to the SHI when compared with Asacol. Mezavant may therefore be a suitable first-line option for the induction and maintenance of remission in UC.</p

A non-canonical RNA silencing pathway promotes mRNA degradation in basal fungi

The increasing knowledge on the functional relevance of endogenous small RNAs (esRNAs) as riboregulators has stimulated the identification and characterization of these molecules in numerous eukaryotes. In the basal fungus Mucor circinelloides, an emerging opportunistic human pathogen, esRNAs that regulate the expression of many protein coding genes have been described. These esRNAs share common machinery for their biogenesis consisting of an RNase III endonuclease Dicer, a single Argonaute protein and two RNA-dependent RNA polymerases. We show in this study that, besides participating in this canonical dicer-dependent RNA interference (RNAi) pathway, the rdrp genes are involved in a novel dicer-independent degradation process of endogenous mRNAs. The analysis of esRNAs accumulated in wild type and silencing mutants demonstrates that this new rdrp-dependent dicer-independent regulatory pathway, which does not produce sRNA molecules of discrete sizes, controls the expression of target genes promoting the specific degradation of mRNAs by a previously unknown RNase. This pathway mainly regulates conserved genes involved in metabolism and cellular processes and signaling, such as those required for heme biosynthesis, and controls responses to specific environmental signals. Searching the Mucor genome for candidate RNases to participate in this pathway, and functional analysis of the corresponding knockout mutants, identified a new protein, R3B2. This RNase III-like protein presents unique domain architecture, it is specifically found in basal fungi and, besides its relevant role in the rdrp-dependent dicer-independent pathway, it is also involved in the canonical dicer-dependent RNAi pathway, highlighting its crucial role in the biogenesis and function of regulatory esRNAs. The involvement of RdRPs in RNA degradation could represent the first evolutionary step towards the development of an RNAi mechanism and constitutes a genetic link between mRNA degradation and post-transcriptional gene silencing

Mapping the prion protein distribution in marsupials: insights from comparing opossum with mouse CNS

The cellular form of the prion protein (PrP(C)) is a sialoglycoprotein widely expressed in the central nervous system (CNS) of mammalian species during neurodevelopment and in adulthood. The location of the protein in the CNS may play a role in the susceptibility of a species to fatal prion diseases, which are also known as the transmissible spongiform encephalopathies (TSEs). To date, little is known about PrP(C) distribution in marsupial mammals, for which no naturally occurring prion diseases have been reported. To extend our understanding of varying PrP(C) expression profiles in different mammals we carried out a detailed expression analysis of PrP(C) distribution along the neurodevelopment of the metatherian South American short-tailed opossum (Monodelphis domestica). We detected lower levels of PrP(C) in white matter fiber bundles of opossum CNS compared to mouse CNS. This result is consistent with a possible role for PrP(C) in the distinct neurodevelopment and neurocircuitry found in marsupials compared to other mammalian species

Developmental learning impairments in a rodent model of nodular heterotopia

Developmental malformations of neocortex—including microgyria, ectopias, and periventricular nodular heterotopia (PNH)—have been associated with language learning impairments in humans. Studies also show that developmental language impairments are frequently associated with deficits in processing rapid acoustic stimuli, and rodent models have linked cortical developmental disruption (microgyria, ectopia) with rapid auditory processing deficits. We sought to extend this neurodevelopmental model to evaluate the effects of embryonic (E) day 15 exposure to the anti-mitotic teratogen methylazoxymethanol acetate (MAM) on auditory processing and maze learning in rats. Extensive cortical anomalies were confirmed in MAM-treated rats post mortem. These included evidence of laminar disruption, PNH, and hippocampal dysplasia. Juvenile auditory testing (P21–42) revealed comparable silent gap detection performance for MAM-treated and control subjects, indicating normal hearing and basic auditory temporal processing in MAM subjects. Juvenile testing on a more complex two-tone oddball task, however, revealed a significant impairment in MAM-treated as compared to control subjects. Post hoc analysis also revealed a significant effect of PNH severity for MAM subjects, with more severe disruption associated with greater processing impairments. In adulthood (P60–100), only MAM subjects with the most severe PNH condition showed deficits in oddball two-tone processing as compared to controls. However, when presented with a more complex and novel FM sweep detection task, all MAM subjects showed significant processing deficits as compared to controls. Moreover, post hoc analysis revealed a significant effect of PNH severity on FM sweep processing. Water Maze testing results also showed a significant impairment for spatial but not non-spatial learning in MAM rats as compared to controls. Results lend further support to the notions that: (1) generalized cortical developmental disruption (stemming from injury, genetic or teratogenic insults) leads to auditory processing deficits, which in turn have been suggested to play a causal role in language impairment; (2) severity of cortical disruption is related to the severity of processing impairments; (3) juvenile auditory processing deficits appear to ameliorate with maturation, but can still be elicited in adulthood using increasingly complex acoustic stimuli; and (4) malformations induced with MAM are also associated with generalized spatial learning deficits. These cumulative findings contribute to our understanding of the behavioral consequences of cortical developmental pathology, which may in turn elucidate mechanisms contributing to developmental language learning impairment in humans