Publications by authors named "Marchan D"

Image-processing pipelines require the design of complex workflows combining many different steps that bring the raw acquired data to a final result with biological meaning. In the image-processing domain of cryo-electron microscopy single-particle analysis (cryo-EM SPA), hundreds of steps must be performed to obtain the three-dimensional structure of a biological macromolecule by integrating data spread over thousands of micrographs containing millions of copies of allegedly the same macromolecule. The execution of such complicated workflows demands a specific tool to keep track of all these steps performed.

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Cryogenic electron microscopy (Cryo-EM) has been established as one of the key players in structural biology. It can reconstruct a 3D model of a sample at a near-atomic resolution. With the increasing number of facilities, faster microscopes, and new imaging techniques, there is a growing demand for algorithms and programs able to process the so-called movie data produced by the microscopes in real time while preserving a high resolution and maximal information.

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Hormogastrid earthworms are found in the diversity hotspot of the Franco-Iberian domain, together with the better-known family Lumbricidae. Integrative systematics (the combination of morphological, molecular and ecological data) have increased our knowledge of the diversity and evolutionary history of these earthworms, highlighting unresolved taxonomic conflicts. One example of a species group in need of integrative taxonomic revision is the genus Boucheona in France.

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Earthworm diversity and ecology in Pakistan is poorly known, especially in the region of Azad Jammu & Kashmir. An earthworm community survey assisted by genetic barcoding detected an unidentified species which could constitute a new record for Pakistan. Morphological study revealed its identity as Perelia kaznakovi.

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There is a gap in our knowledge of microorganization and the functioning of ovaries in earthworms (Crassiclitellata) and allied taxa. Recent analyses of ovaries in microdriles and leech-like taxa revealed that they are composed of syncytial germline cysts accompanied by somatic cells. Although the pattern of cyst organization is conserved across Clitellata - each cell is connected via one intercellular bridge (ring canal) to the central and anuclear cytoplasmic mass termed the cytophore - this system shows high evolutionary plasticity.

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The number of maps deposited in public databases (Electron Microscopy Data Bank, EMDB) determined by cryo-electron microscopy has quickly grown in recent years. With this rapid growth, it is critical to guarantee their quality. So far, map validation has primarily focused on the agreement between maps and models.

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In spite of the high conservation value of soil fauna, the evaluation of their conservation status has usually been neglected. This is more evident for earthworms, one of the most important ecosystem service providers in temperate habitats but rarely the subject of conservation research. These studies have not been developed in Western Europe, which comprises high diversity and several early-branching, relic genera.

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Article Synopsis
  • Extreme weather events are increasing due to climate change, creating challenging habitats for species like the riparian earthworm Eiseniella tetraedra, which must adapt to conditions like freezing and drought.
  • Experiments showed that under cold conditions, 84 genes were expressed differently, indicating that while the earthworm can acclimate to low temperatures, it may not tolerate freezing well.
  • In desiccation conditions, 163 genes were differentially expressed, revealing mechanisms for cell protection and resource conservation, with specific genes upregulated for DNA repair and downregulated for lipid metabolism.
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The Massif Central in France could potentially harbor numerous ancient endemic lineages owing to its long history of continuous geological stability. Several endemic earthworm species inhabit the area, with Allolobophora (Gatesona) chaetophora, Helodrilus (Acystodrilus) and Avelona ligra showing hints of a common evolutionary origin. However, the phylogenetic relationships and taxonomic status of the species remain to be studied through integrative molecular and morphological methods.

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Uncovering the genetic and evolutionary basis of cryptic speciation is a major focus of evolutionary biology. Next Generation Sequencing (NGS) allows the identification of genome-wide local adaptation signatures, but has rarely been applied to cryptic complexes - particularly in the soil milieu - as it is the case with integrative taxonomy. The earthworm genus Carpetania, comprising six previously suggested putative cryptic lineages, is a promising model to study the evolutionary phenomena shaping cryptic speciation in soil-dwelling lineages.

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The earthworm family Hormogastridae is a relatively diverse group in the Western Mediterranean basin. Since 1887, around thirty species have been described and assigned to four genera. However, from 2010 on, molecular, ecological and morphological studies have questioned the validity of those genera.

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DNA barcoding of 172 anecic Octodrilus specimens collected in NE Italy and bordering Croatia has been carried out. The Bayesian phylogenetic tree showed high support for almost all currently recognized species, however, some unexpected results also appeared. The clade representing Oc.

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Spatial and temporal aspects of the evolution of cryptic species complexes have received less attention than species delimitation within them. The phylogeography of the cryptic complex Hormogaster elisae (Oligochaeta, Hormogastridae) lacks knowledge on several aspects, including the small-scale distribution of its lineages or the palaeogeographic context of their diversification. To shed light on these topics, a dense specimen collection was performed in the center of the Iberian Peninsula - resulting in 28 new H.

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Earthworm taxonomy and evolutionary biology remain a challenge because of their scarce distinct morphological characters of taxonomic value, the morphological convergence by adaptation to the uniformity of the soil where they inhabit, and their high plasticity when challenged with stressful or new environmental conditions. Here we present a phylogenomic study of the family Hormogastridae, representing also the first piece of work of this type within earthworms. We included seven transcriptomes of the group representing the main lineages as previously-described, analysed in a final matrix that includes twelve earthworms and eleven outgroups.

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Comparative phylogeography of widespread species that span the same geographic areas can elucidate the influence of historical events on current patterns of biodiversity, identify patterns of co-vicariance, and therefore aid the understanding of general evolutionary processes. Soil-dwelling animals present characteristics that make them suitable for testing the effect of the palaeogeographical events on their distribution and diversification, such as their low vagility and population structure. In this study, we shed light on the spatial lineage diversification and cladogenesis of two widely-distributed cosmopolitan and invasive earthworms (Aporrectodea rosea and A.

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Conflict among data sources can be frequent in evolutionary biology, especially in cases where one character set poses limitations to resolution. Earthworm taxonomy, for example, remains a challenge because of the limited number of morphological characters taxonomically valuable. An explanation to this may be morphological convergence due to adaptation to a homogeneous habitat, resulting in high degrees of homoplasy.

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