Insights into the origin of metazoan filopodia and microvilli.

Filopodia are fine actin-based cellular projections used for both environmental sensing and cell motility, and they are essential organelles for metazoan cells. In this study, we reconstruct the origin of metazoan filopodia and microvilli. We first report on the evolutionary assembly of the filopodial molecular toolkit and show that homologs of many metazoan filopodial components, including fascin and myosin X, were already present in the unicellular or colonial progenitors of metazoans. Furthermore, we find that the actin crosslinking protein fascin localizes to filopodia-like structures and microvilli in the choanoflagellate Salpingoeca rosetta. In addition, homologs of filopodial genes in the holozoan Capsaspora owczarzaki are upregulated in filopodia-bearing cells relative to those that lack them. Therefore, our findings suggest that proteins essential for metazoan filopodia and microvilli are functionally conserved in unicellular and colonial holozoans and that the last common ancestor of metazoans bore a complex and specific filopodial machinery

The Capsaspora genome reveals a complex unicellular prehistory of animals

Suga, Hiroshi et al.-- This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.To reconstruct the evolutionary origin of multicellular animals from their unicellular ancestors, the genome sequences of diverse unicellular relatives are essential. However, only the genome of the choanoflagellate Monosiga brevicollis has been reported to date. Here we completely sequence the genome of the filasterean Capsaspora owczarzaki, the closest known unicellular relative of metazoans besides choanoflagellates. Analyses of this genome alter our understanding of the molecular complexity of metazoans' unicellular ancestors showing that they had a richer repertoire of proteins involved in cell adhesion and transcriptional regulation than previously inferred only with the choanoflagellate genome. Some of these proteins were secondarily lost in choanoflagellates. In contrast, most intercellular signalling systems controlling development evolved later concomitant with the emergence of the first metazoans. We propose that the acquisition of these metazoan-specific developmental systems and the co-option of pre-existing genes drove the evolutionary transition from unicellular protists to metazoans. © 2013 Macmillan Publishers Limited. All rights reserved.H.S. was supported by the Marie Curie Intra-European Fellowship within the 7th European Community Framework Programme. Genome sequencing, assembly and some supporting analysis was supported by grants from the National Human Genome Research Institute (HG003067-05 through HG003067-10), as were C.N., C.R., B.H. and Z.C. B.F.L. and A.J.R. acknowledge financial support through the Canadian Research Chair program. This study was supported by an ICREA contract, a European Research Council Starting Grant (ERC-2007-StG-206883) and a grant (BFU2011-23434) from the Spanish Ministry of the Economy and Competitiveness (MINECO) awarded to I.R.-T. M.V. was supported by CNRS, the Agence Nationale de la Recherche (ANR grant BLAN-0294) and the Institut Universitaire de France.Peer Reviewe

Pyridine-driven assembly of Zn(II) and Cd(II) complexes with 2-furoic acid. The role of water in a structural transformation

Understanding the factors governing the self-assembly of organic ligands with metal ions is essential to engineering target molecular arrangements with the desired properties. Indeed, small modifications of the synthetic conditions lead to the obtention of different complexes, varying from discrete monomers to coordination polymers (CPs). Based on the potential coordinating ability of 2-furoic acid (2-FA), we prepared five Zn(II) and Cd(II) complexes to study the behavior of the furane O atom and the competitiveness of the M-O bond formation in methanol (MeOH). Reactions between M(OAc)2·2H2O (M = Zn(II), Cd(II)), 2-FA, and two p-substituted pyridine ligands (isonicotinamide (Isn) and 4-acetylpyridine (4-Acpy)) in MeOH yielded the two dimers [Zn(μ-2-FA)(2-FA)(Isn)2]2 (1) and [Cd(μ-2-FA)(2-FA)(Isn)2]2 (2), the dimeric paddle-wheel [Zn(μ-2-FA)2(4-Acpy)]2 (3), and the monomer [Cd(2-FA)2(4-Acpy)2(OH2)] (4). Their crystal structures have been studied, observing diverse coordination numbers between five and seven and diverse coordination modes of the carboxylate groups. Interestingly, the recrystallization of 4 in acetonitrile (ACN) resulted in a dissolution-recrystallization structural transformation (DRST), leading to an intricate coordination polymer (CP) with the formula {[Cd(μ-2-FA)(2-FA)(OH2)2]n[Cd(μ-2-FA)(2-FA)(4-Acpy)(OH2)]n} (5) exhibiting coordination of the furane O atom. Within this collection of arrangements, 2-FA displayed a great diversity of coordination modes that were combined and interchanged in the DRST process. Their photophysical properties in solution have been analyzed and their quantum yields calculated. Likewise, further insight into the DRST process was obtained from fluorescence measurements. From these results, a pathway for the structural transformation highlighting the crucial role of solvents has been proposed

Transfection of Capsaspora owczarzaki, a close unicellular relative of animals

How animals emerged from their unicellular ancestor remains a major evolutionary question. New genome data from the closest unicellular relatives of animals have provided important insights into the evolution of animal multicellularity. We know that the unicellular ancestor of animals had an unexpectedly complex genetic repertoire, including many genes that are key to animal development and multicellularity. Thus, assessing the function of these genes among unicellular relatives of animals is key to understanding how they were co-opted at the onset of the Metazoa. However, such analyses have been hampered by the lack of genetic tools. Progress has been made in choanoflagellates and teretosporeans, two of the three lineages closely related to animals, whereas no tools are yet available for functional analysis in the third lineage: the filastereans. Importantly, filastereans have a striking repertoire of genes involved in transcriptional regulation and other developmental processes. Here, we describe a reliable transfection method for the filasterean Capsaspora owczarzaki. We also provide a set of constructs for visualising subcellular structures in live cells. These tools convert Capsaspora into a unique experimentally tractable organism to use to investigate the origin and evolution of animal multicellularity.Fil: Parra Acero, Helena. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales. Departamento de Biodiversidad y Biología Evolutiva; EspañaFil: Ros Rocher, Núria. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales. Departamento de Biodiversidad y Biología Evolutiva; EspañaFil: Perez Posada, Alberto. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales. Departamento de Biodiversidad y Biología Evolutiva; EspañaFil: Kożyczkowska, Aleksandra. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales. Departamento de Biodiversidad y Biología Evolutiva; EspañaFil: Sánchez Pons, Núria. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales. Departamento de Biodiversidad y Biología Evolutiva; EspañaFil: Nakata, Azusa. Prefectural University of Hiroshima; JapónFil: Suga, Hiroshi. Prefectural University of Hiroshima; JapónFil: Najle, Sebastián Rodrigo. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales. Departamento de Biodiversidad y Biología Evolutiva; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Ruiz Trillo, Iñaki. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales. Departamento de Biodiversidad y Biología Evolutiva; España. Institució Catalana de Recerca i Estudis Avancats; España. Universidad de Barcelona; Españ

Pyridine-driven assembly of Zn(II) and Cd(II) complexes with 2-furoic acid. The role of water in a structural transformation

Understanding the factors governing the self-assembly of organic ligands with metal ions is essential to engineering target molecular arrangements with the desired properties. Indeed, small modifications of the synthetic conditions lead to the obtention of different complexes, varying from discrete monomers to coordination polymers (CPs). Based on the potential coordinating ability of 2-furoic acid (2-FA), we prepared five Zn(II) and Cd(II) complexes to study the behavior of the furane O atom and the competitiveness of the M-O bond formation in methanol (MeOH). Reactions between M(OAc)(2 center dot)2H(2)O (M = Zn(II), Cd(II)), 2-FA, and two p-substituted pyridine ligands (isonicotinamide (Isn) and 4-acetylpyridine (4-Acpy)) in MeOH yielded the two dimers [Zn(mu-2-FA)(2-FA)(Isn)(2)](2) (1) and [Cd(mu-2-FA)(2-FA)(Isn)(2)](2) (2), the dimeric paddle-wheel [Zn(mu-2-FA)(2)(4-Acpy)](2) (3), and the monomer [Cd(2-FA)(2)(4-Acpy)(2)(OH2)] (4). Their crystal structures have been studied, observing diverse coordination numbers between five and seven and diverse coordination modes of the carboxylate groups. Interestingly, the recrystallization of 4 in acetonitrile (ACN) resulted in a dissolution-recrystallization structural transformation (DRST), leading to an intricate coordination polymer (CP) with the formula {[Cd(mu-2-FA)(2-FA)(OH2)(2)](n)[Cd(mu-2-FA)(2-FA)(4-Acpy)(OH2)](n)} (5) exhibiting coordination of the furane O atom. Within this collection of arrangements, 2-FA displayed a great diversity of coordination modes that were combined and interchanged in the DRST process. Their photophysical properties in solution have been analyzed and their quantum yields calculated. Likewise, further insight into the DRST process was obtained from fluorescence measurements. From these results, a pathway for the structural transformation highlighting the crucial role of solvents has been proposed

Integrin-Mediated Adhesion in the Unicellular Holozoan Capsaspora owczarzaki.

In animals, cell-matrix adhesions are essential for cell migration, tissue organization, and differentiation, which have central roles in embryonic development [1-6]. Integrins are the major cell surface adhesion receptors mediating cell-matrix adhesion in animals. They are heterodimeric transmembrane proteins that bind extracellular matrix (ECM) molecules on one side and connect to the actin cytoskeleton on the other [7]. Given the importance of integrin-mediated cell-matrix adhesion in development of multicellular animals, it is of interest to discover when and how this machinery arose during evolution. Comparative genomic analyses have shown that core components of the integrin adhesome pre-date the emergence of animals [8-11]; however, whether it mediates cell adhesion in non-metazoan taxa remains unknown. Here, we investigate cell-substrate adhesion in Capsaspora owczarzaki, the closest unicellular relative of animals with the most complete integrin adhesome [11, 12]. Previous work described that the life cycle of C. owczarzaki (hereafter, Capsaspora) includes three distinct life stages: adherent; cystic; and aggregative [13]. Using an adhesion assay, we show that, during the adherent life stage, C. owczarzaki adheres to surfaces using actin-dependent filopodia. We show that integrin β2 and its associated protein vinculin localize as distinct patches in the filopodia. We also demonstrate that substrate adhesion and integrin localization are enhanced by mammalian fibronectin. Finally, using a specific antibody for integrin β2, we inhibited cell adhesion to a fibronectin-coated surface. Our results suggest that adhesion to the substrate in C. owczarzaki is mediated by integrins. We thus propose that integrin-mediated adhesion pre-dates the emergence of animals

Genetic, molecular and cellular approaches to the analysis of maize embryo development

The development of embryo structures in plants is essential for the formation of the adult plant organs. In cereals, this process has distinct features which have attracted attention from different points of view. Differential gene expression analyses have been used in order to identify genes useful as molecular markers of certain physiological, molecular or developmental processes. Several maize mutants affected in embryo development have been isolated, but only a fraction of them have been characterized at the molecular level. Molecular markers can be useful in the characterization of embryo defective mutants. Here, we describe the different techniques used in the identification of molecular marker genes for embryo development. We describe in more detail some groups of genes coding for cell wall proteins. We also describe the application of these molecular markers in the characterization of some embryo mutants

Functional brain connectivity prior to the COVID-19 outbreak moderates the effects of coping and perceived stress on mental health changes. A first year of COVID-19 pandemic follow-up study.

Background: The COVID-19 pandemic provides a unique opportunity to investigate the psychological impact of a global major adverse situation. Our aim was to examine, in a longitudinal prospective study, the demographic, psychological, and neurobiological factors associated with interindividual differences in resilience to the mental health impact of the pandemic. Methods: We included 2023 healthy participants (age: 54.32 ± 7.18 years, 65.69% female) from the Barcelona Brain Health Initiative cohort. A linear mixed model was used to characterize the change in anxiety and depression symptoms based on data collected both pre-pandemic and during the pandemic. During the pandemic, psychological variables assessing individual differences in perceived stress and coping strategies were obtained. In addition, in a subsample (n = 433, age 53.02 ± 7.04 years, 46.88% female) with pre-pandemic resting-state functional magnetic resonance imaging available, the system segregation of networks was calculated. Multivariate linear models were fitted to test associations between COVID-19-related changes in mental health and demographics, psychological features, and brain network status. Results: The whole sample showed a general increase in anxiety and depressive symptoms after the pandemic onset, and both age and sex were independent predictors. Coping strategies attenuated the impact of perceived stress on mental health. The system segregation of the frontoparietal control and default mode networks were found to modulate the impact of perceived stress on mental health. Conclusions: Preventive strategies targeting the promotion of mental health at the individual level during similar adverse events in the future should consider intervening on sociodemographic and psychological factors as well as their interplay with neurobiological substrates

Les competències transversals i les auditories als laboratoris de pràctiques de la Facultat de Química: desenvolupament i anàlisi

S’ha treballat la formació competencial dels estudiants mitjançant la realització d’auditories del sistema de gestió de la qualitat dels laboratoris de practiques de la Facultat de Química. Per fer aquesta tasca, s’ha seleccionat com auditors a 102 estudiants de l’assignatura “Qualitat i Prevenció” del Grau de Química, els quals, després d’una breu formació, han actuat com auditors en 49 auditories, la qual cosa ha implicat també la participació de 99 estudiants i 49 professors com a interlocutors en els laboratoris auditats. En total han estat auditats 49 torns de pràctiques relacionats amb els diferents tipus d’assignatures pràctiques impartides per tots els departaments de la Facultat i corresponents als tres graus que s’imparteixen (Química, Enginyeria Química i Enginyeria de Materials), havent estat auditats pràcticament tots els laboratoris docents de la Facultat. Seguint els objectius del projecte, els estudiants han pogut treballar competències transversals relacionades amb l’ètica, la capacitat d’expressió oral i escrita, la capacitat de diàleg, la capacitat de lideratge, l’anàlisi i la interpretació de dades, la gestió de la qualitat, el treball respectuós amb el medi ambient, la seguretat, etc. Per tant, aquest projecte ha sigut una eina important en la seva formació. D’altra banda, dels resultats dels informes d’auditoria realitzats pels estudiants, s’han posat de manifest una sèrie de mancances i problemes als laboratoris que estan sent analitzats per tal de millorar la qualitat de les pràctiques. Finalment, s’han realitzat enquestes de satisfacció a tots els grups implicats (estudiants auditors, estudiants auditats, professors auditats) i els resultats de les mateixes han posat de manifest un alt grau de satisfacció amb la feina feta i la manera de fer-la.PMI

Low transmission of SARS-CoV-2 derived from children in family clusters: An observational study of family households in the Barcelona Metropolitan Area, Spain

Background: Family clusters offer a good opportunity to study viral transmission in a stable setting. We aimed to analyze the specific role of children in transmission of SARS-CoV-2 within households. Methods: A prospective, longitudinal, observational study, including children with documented acute SARS-CoV-2 infection attending 22 summer-schools in Barcelona, Spain, was performed. Moreover, other patients and families coming from other school-like environments that voluntarily accessed the study were also studied. A longitudinal follow-up (5 weeks) of the family clusters was conducted to determine whether the children considered to be primary cases were able to transmit the virus to other family members. The household reproduction number (Re*) and the secondary attack rate (SAR) were calculated. Results: 1905 children from the summer schools were screened for SARS-CoV-2 infection and 22 (1.15%) tested positive. Moreover, 32 additional children accessed the study voluntarily. Of these, 37 children and their 26 households were studied completely. In half of the cases (13/26), the primary case was considered to be a child and secondary transmission to other members of the household was observed in 3/13, with a SAR of 14.2% and a Re* of 0.46. Conversely, the SAR of adult primary cases was 72.2% including the kids that gave rise to the contact tracing study, and 61.5% without them, and the estimated Re* was 2.6. In 4/13 of the paediatric primary cases (30.0%), nasopharyngeal PCR was persistently positive > 1 week after diagnosis, and 3/4 of these children infected another family member (p<0.01). Conclusions: Children may not be the main drivers of the infection in household transmission clusters in the study population. A prolonged positive PCR could be associated with higher transmissibility