atonal- and achaete-scute-related genes in the annelid Platynereis dumerilii: insights into the evolution of neural basic-Helix-Loop-Helix genes

Functional studies in model organisms, such as vertebrates and Drosophila, have shown that basic Helix-loop-Helix (bHLH) proteins have important roles in different steps of neurogenesis, from the acquisition of neural fate to the differentiation into specific neural cell types. However, these studies highlighted many differences in the expression and function of orthologous bHLH proteins during neural development between vertebrates and Drosophila. To understand how the functions of neural bHLH genes have evolved among bilaterians, we have performed a detailed study of bHLH genes during nervous system development in the polychaete annelid, Platynereis dumerilii, an organism which is evolutionary distant from both Drosophila and vertebrates.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Origin and diversification of the basic helix-loop-helix gene family in metazoans: insights from comparative genomics

BACKGROUND: Molecular and genetic analyses conducted in model organisms such as Drosophila and vertebrates, have provided a wealth of information about how networks of transcription factors control the proper development of these species. Much less is known, however, about the evolutionary origin of these elaborated networks and their large-scale evolution. Here we report the first evolutionary analysis of a whole superfamily of transcription factors, the basic helix-loop-helix (bHLH) proteins, at the scale of the whole metazoan kingdom. RESULTS: We identified in silico the putative full complement of bHLH genes in the sequenced genomes of 12 different species representative of the main metazoan lineages, including three non-bilaterian metazoans, the cnidarians Nematostella vectensis and Hydra magnipapillata and the demosponge Amphimedon queenslandica. We have performed extensive phylogenetic analyses of the 695 identified bHLHs, which has allowed us to allocate most of these bHLHs to defined evolutionary conserved groups of orthology. CONCLUSION: Three main features in the history of the bHLH gene superfamily can be inferred from these analyses: (i) an initial diversification of the bHLHs has occurred in the pre-Cambrian, prior to metazoan cladogenesis; (ii) a second expansion of the bHLH superfamily occurred early in metazoan evolution before bilaterians and cnidarians diverged; and (iii) the bHLH complement during the evolution of the bilaterians has been remarkably stable. We suggest that these features may be extended to other developmental gene families and reflect a general trend in the evolution of the developmental gene repertoires of metazoans

Do Disquete às Nuvens: a saga da primeira revista eletrônica científica brasileira

Atualmente não se questiona mais a substituição do formato impresso pelo eletrônico. Entretanto, no final do século XX esse tema era fonte de debate acalorado entre os editores das revistas cientificas. O objetivo deste trabalho foi mostrar a evolução da primeira revista eletrônica científica brasileira, mantida e editada ininterruptamente desde 1995 pelo Centro de Estudos de Venenos e Animais Peçonhentos da Unesp (CEVAP). Denominada inicialmente The Journal of Venomous Animals and Toxins (ISSN 0104-7930), a revista que sempre foi publicada em inglês era fasciculada e distribuída em disquetes de 3.5” em sua primeira fase. A partir de 2003, o escopo foi ampliado e recebeu novo ISSN (1678-9199) e seu título passou a ser The Journal of Venomous Animals and Toxins including Tropical Diseases (JVATiTD). A partir de 2013, estabeleceu parceria com a BioMed Central, um publisher internacional de acesso aberto, membro do grupo Springer-Nature, e sua homepage passou a ser: https://jvat.biomedcentral.com/. A história de sucesso dessa publicação se deve, principalmente, ao processo gradual de mudança de paradigma, ou seja, o primeiro suporte foi o disquete com possibilidade de impressão do fascículo, a seguir o CD-ROM enviado pelo correio permitindo a leitura na tela do computador e, por fim, a distribuição online através da homepage e a implantação da submissão eletrônica de manuscritos. Atualmente, além de ser publicada em fluxo contínuo, a revista também incentiva os autores a incluir áudios e vídeos como material suplementar

Como aumentar o fator de impacto nas bases Web of Science (WoS) e Scopus (Scimago): ações implementadas pelo The Journal of Venomous Animals and Toxins including Tropical Diseases

O The Journal of Venomous Animals and Toxins including Tropical Diseases (JVATiTD) foi indexado nas bases Web of Science (WoS) e Scopus (Scimago) em 2006. Entre 2007 e 2012 o fator de impacto (FI) estabilizou-se entre 0.30 e 0.55. Para aumentá-lo, em 2013 estabeleceu-se parceria com a BioMed Central-Springer-Nature e uma série de ações foram propostas e implementadas com vistas a alcançar o patamar de 2.0 em cinco anos. As ações foram as seguintes: publicar em fluxo contínuo, buscar novos indexadores estratégicos, reavaliar o corpo editorial, priorizar conteúdos de qualidade, cortar supérfluos, estimular publicação em multimídia, manter um banco de dados atualizado, e publicar séries temáticas e especiais. Para os editores associados foram feitas as seguintes sugestões: participar em eventos da área e em grupos consolidados de pesquisa, além de dar parecer científico para outras revistas. É possível concluir previamente que a nova parceria foi estratégica, pois em 2017 atingiu-se impacto de citações acima de 1.0 tanto no Web of Science (WoS), quanto no Scopus (Scimago). Isso certamente deverá atrair a submissão de bons manuscritos, aumentar o prestígio, a visibilidade mundial e o aumento do número de citações. Como consequência direta, o FI deverá aumentar nos anos vindouros

Impacto das correções das citações erradas na base Web of Science (WoS) sobre o Fator de Impacto - um case de sucesso

Em 2015 as revistas científicas impressas completaram 350 anos de existência. É fácil compreender que neste longo período de tempo as padronizações de citação (metadados) foram bem estabelecidas. A partir de 1991 Paul Ginsparg lançou nos EUA a primeira revista eletrônica que se tem notícia. Infelizmente até o momento não existe uma padronização definitiva de como citar os artigos científicos publicados por meio desta nova plataforma. Um dos desafios para esta padronização é a publicação em fluxo contínuo, modalidade nova que surgiu com as revistas digitais. Assim, as bases de dados muitas vezes cometem erros na citação das referências, uma vez que os autores por desconhecimento também citam errado. Os objetivos deste trabalho foram corrigir as referências citadas erroneamente do The Journal of Venomous Animals and Toxins including Tropical Diseases (JVATiTD) nos últimos cinco anos na base Web of Science (WoS) com vistas a avaliar o impacto desta ação. Os resultados publicados em 2018 pelo Journal Citation Reports da Clarivate Analytics foram os seguintes: o Fator de Impacto (FI) de dois anos cresceu de 1.44 para 1.78, e o de cinco de 1.12 para 1.74. Este case de sucesso mostra claramente que somente as citações completas e consideradas válidas são contabilizadas no cálculo do FI. Assim, torna-se imperativo que os Editores incluam o monitoramento dos indexadores nas atividades da equipe da revista, em especial na base WoS, de forma a evitar erros que possam comprometer o real valor do FI. Esta ação otimiza os indicadores bibliométricos e melhora o prestígio do periódico, culminando com aumento da visibilidade e da procura e submissão de manuscritos de impacto

Coe Genes Are Expressed in Differentiating Neurons in the Central Nervous System of Protostomes

Genes of the coe (collier/olfactory/early B-cell factor) family encode Helix-Loop-Helix transcription factors that are widely conserved in metazoans and involved in many developmental processes, neurogenesis in particular. Whereas their functions during vertebrate neural tube formation have been well documented, very little is known about their expression and role during central nervous system (CNS) development in protostomes. Here we characterized the CNS expression of coe genes in the insect Drosophila melanogaster and the polychaete annelid Platynereis dumerilii, which belong to different subgroups of protostomes and show strikingly different modes of development. In the Drosophila ventral nerve cord, we found that the Collier-expressing cells form a subpopulation of interneurons with diverse molecular identities and neurotransmitter phenotypes. We also demonstrate that collier is required for the proper differentiation of some interneurons belonging to the Eve-Lateral cluster. In Platynereis dumerilii, we cloned a single coe gene, Pdu-coe, and found that it is exclusively expressed in post mitotic neural cells. Using an original technique of in silico 3D registration, we show that Pdu-coe is co-expressed with many different neuronal markers and therefore that, like in Drosophila, its expression defines a heterogeneous population of neurons with diverse molecular identities. Our detailed characterization and comparison of coe gene expression in the CNS of two distantly-related protostomes suggest conserved roles of coe genes in neuronal differentiation in this clade. As similar roles have also been observed in vertebrates, this function was probably already established in the last common ancestor of all bilaterians

Orthologs of key vertebrate neural genes are expressed during neurogenesis in the annelid Platynereis dumerilii.

International audienceThe molecular mechanisms underlying the formation and patterning of the nervous system are relatively poorly understood for lophotrochozoans (like annelids) as compared with ecdysozoans (especially Drosophila) and deuterostomes (especially vertebrates). Therefore, we have undertaken a candidate gene approach to study aspects of neurogenesis in a polychaete annelid Platynereis dumerilii. We determined the spatiotemporal expression for Platynereis orthologs of four genes (SoxB, Churchill, prospero/Prox, and SoxC) known to play key roles in vertebrate neurogenesis. During Platynereis development, SoxB is expressed in the neuroectoderm and its expression switches off when committed neural precursors are formed. Subsequently, Prox is expressed in all differentiating neural precursors in the central and peripheral nervous systems. Finally, SoxC and Churchill are transcribed in patterns consistent with their involvement in neural differentiation. The expression patterns of Platynereis SoxB and Prox closely resemble those in Drosophila and vertebrates--this suggests that orthologs of these genes play similar neurogenic roles in all bilaterians. Whereas Platynereis SoxC, like its vertebrate orthologs, plays a role in neural cell differentiation, related genes in Drosophila do not appear to be involved in neurogenesis. Finally, conversely to Churchill in Platynereis, vertebrate orthologs of this gene are expressed during neuroectoderm formation, but not later during nerve cell differentiation; in the insect lineage, homologs of these genes have been secondarily lost. In spite of such instances of functional divergence or loss, the present study shows conspicuous similarities in the genetic control of neurogenesis among bilaterians. These commonalities suggest that key features of the genetic program for neurogenesis are ancestral to bilaterians

Climate change and land subsidence in the frame of "Venezia 2021" project : the deterioration of architectural stone materials

The overflowing of the canals and the flooding of the pedestrian walkways are the consequences of the well-known periodic large water inflow into the Venetian lagoon (high water or acqua alta). These phenomena lead the strong degradation of the stone buildings over time. With the aim to better understand the effects of high water and support the best actions and practices for preserving the cultural heritage of Venice by Municipality and Superintendences, thirty samples of five varieties of carbonate lithotypes were exposed to natural weathering in different Venetian areas and on Torcello island. The specimens were periodically monitored and compared with samples made of the same lithologies subjected to accelerated artificial aging tests. The results concerning the main deterioration morphologies observed on all the samples after three years of exposure are here presented and commented

Autophagy mediates phosphatidylserine exposure and phagosome degradation during apoptosis through specific functions of GABARAP/LGG-1 and LC3/LGG-2

International audiencePhagocytosis and macroautophagy/autophagy are 2 processes involved in lysosome-mediated clearance of extracellular and intracellular components, respectively. Recent studies have identified the recruitment of the autophagic protein LC3 during phagocytosis of apoptotic corpses in what is now called LC3-associated phagocytosis (LAP). LAP is a distinct process from autophagy but it relies on some members of the autophagy pathway to allow efficient degradation of the phagocytosed cargo. We investigated whether both LC3/LGG-2 and GABARAP/LGG-1 are involved in phagocytosis of apoptotic corpses during embryonic development of Caenorhabditis elegans. We discovered that both LGG-1 and LGG-2 are involved in the correct elimination of apoptotic corpses, but that they have different functions. lgg-1 and lgg-2 mutants present a delay in phagocytosis of apoptotic cells but genetic analyses indicate that LGG-1 and LGG-2 act upstream and downstream of the engulfment pathways, respectively. Moreover, LGG-1 and LGG-2 display different cellular localizations with enrichment in apoptotic corpses and phagocytic cells, respectively. For both LGG-1 and LGG-2, subcellular localization is vesicular and dependent on UNC-51/ULK1, BEC-1/BECN1 and the lipidation machinery, indicating that their functions during phagocytosis of apoptotic corpses mainly rely on autophagy. Finally, we show that LGG-1 is involved in the exposure of the 'eat-me signal' phosphatidylserine at the surface of the apoptotic cell to allow its recognition by the phagocytic cell, whereas LGG-2 is involved in later steps of phagocytosis to allow efficient cell corpse clearance by mediating the maturation/degradation of the phagosome