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Vandenboschia speciosa is an endangered tetraploid fern species with a large genome (10.5 Gb). Its geographical distribution is characterized by disjoined tertiary flora refuges, with relict populations that survived past climate crises. Here, we analyzed the transposable elements (TEs) and found that they comprise approximately 76% of the V. speciosa genome, thus being the most abundant type of DNA sequence in this gigantic genome. The V. speciosa genome is composed of 51% and 5.6% of Class I and Class II elements, respectively. LTR retrotransposons were the most abundant TEs in this species (at least 42% of the genome), followed by non-LTR retrotransposons, which constituted at least 8.7% of the genome of this species. We introduce an additional analysis to identify the nature of non-annotated elements (19% of the genome). A BLAST search of the non-annotated con-tigs against the V. speciosa TE database allowed for the identification of almost half of them, which were most likely diverged sequence variants of the annotated TEs. In general, the TE composition in V. speciosa resembles the TE composition in seed plants. In addition, repeat landscapes revealed three episodes of amplification for all TEs, most likely due to demographic changes associated with past climate crises. Key words: climate crisis, demographic changes, endangered species, ferns, genome size, relict populations, tetraploidy, transposable elements, Vandenboschia speciosa. Le Vandenboschia speciosa est une espece menacee de fougere tetraploide a grand genome (10,5 Gb). Sa repartition geographique se caracterise par des refuges floraux tertiaires disjoints, avec des populations reliques qui ont survecu a des crises climatiques anterieures. Dans ce travail, les auteurs analysent les elements transpos-ables (TE) et rapportent qu'ils constituent environ 76 % du genome du V. spieciosa, ils representent ainsi le type de sequence d'ADN le plus abondant dans ce genome gigantesque. Le genome du V. spieciosa est compose a 51 % et a 5,6 % respectivement d'elements de Classe I et de Classe II. Les retrotransposons a LTR etaient les TE les plus abond-ants chez cette espece (au moins 42 % de genome), suivis des retrotransposons non-LTR, lesquels constituaient aumoins 8,7 % du genome de cette espece. Les auteurs ont realise une analyse additionnelle pour identifier la nature des elements non-annotes (19 % du genome). Une analyse BLAST des contigs non-annotes contre une base de don-nees des TE du V. spieciosa a permis d'en identifier pres de la moitie, lesquels constituent vraisemblablement des variants divergents par rapport aux TE annotes. De maniere generale, la composition en TE du V. speciosa ressem-ble a la composition rencontree chez les plantes a graines. De plus, cette caracterisation des sequences repetees suggere que trois episodes d'amplification de tous les TE se seraient produits, vraisemblablement en raison de changements demographiques associes aux crises climatiques passees. Mots-cles: crise climatique, changements demographiques, espece menacees, fougeres, taille du genome, populations reliques, tetraplo'idie, elements transposables, Vandenboschia speciosa., Introduction Transposable elements (TEs) are ubiquitous components of eukaryotic genomes that are considered drivers of genome evolution (Bohne et al. 2008; Belyayev 2014; Bourque et al. 2018), and have a [...]

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Satellite DNAs (SatDNA) are ubiquitously present in eukaryotic genomes and have been recently associated with several biological roles. Understanding the evolution and significance of SatDNA requires an extensive comparison across multiple phylogenetic depths. We combined the RepeatExplorer pipeline and cytogenetic approaches to conduct a comprehensive identification and analysis of the satellitome in 37 species from the genus Drosophila. We identified 188 SatDNA-like families, 112 of them being characterized for the first time. Repeat analysis within a phylogenetic framework has revealed the deeply divergent nature of SatDNA sequences in the Drosophila genus. The SatDNA content varied from 0.54% of the D. arizonae genome to 38.8% of the D. albomicans genome, with the SatDNA content often following a phylogenetic signal. Monomer size and guanine–cytosine-content also showed extreme variation ranging 2–570 bp and 9.1–71.4%, respectively. SatDNA families are shared among closely related species, consistent with the SatDNA library hypothesis. However, we uncovered the emergence of species-specific SatDNA families through amplification of unique or low abundant sequences in a lineage. Finally, we found that genome sizes of the Sophophora subgenus are positively correlated with transposable element content, whereas genome size in the Drosophila subgenus is positively correlated with SatDNA. This finding indicates genome size could be driven by different categories of repetitive elements in each subgenus. Altogether, we conducted the most comprehensive satellitome analysis in Drosophila from a phylogenetic perspective and generated the largest catalog of SatDNA sequences to date, enabling future discoveries in SatDNA evolution and Drosophila genome architecture. [ABSTRACT FROM AUTHOR]

Bivalve mollusks are an important resource due to their socioeconomic value and to the historical and genetic value of some species. Two nationally important oyster species-Portuguese oyster (Crassostrea angulata) and Japanese oyster (Crassostrea gigas) from distinctive areas in Portugal were studied to evaluate their sanitary status. Oysters were sampled from four different sites in Portugal. Oysters collected from Japanese oyster populations were cultivated in a strong ocean-influenced environment and Portuguese oyster populations were cultivated in wild-beds. The histopathological examination of both oyster species revealed the presence of parasites in gills, mantle epithelium, digestive gland tubules and connective tissue, with a moderate prevalence. In both populations was observed hemocytosis in the connective tissue, edema and metaplasia in the digestive gland and tissues necrosis. In wild populations from Sado and Mira estuaries the prevalence of mud blisters and gill lesions were higher than from populations produced on 0.50 m tables from mudflats. Biosecurity measures and diagnostic techniques are fundamental to control pathogenic agents, including the identification of pathogens at an early stage in their life cycles. This will prevent diseases and improve pathogen reduction on transport of animals from different countries and regions to new production areas to avoid the transmission of diseases. [ABSTRACT FROM AUTHOR]

Introduction: Exposure to cat allergens is often difficult to avoid. Here, we evaluated the safety and effectiveness of a depigmented, polymerized cat epithelium extract (Dpg-pol-cat) for the treatment of allergic rhinoconjunctivitis and asthma. Methods: Real-world, retrospective study of patients ≥12 years of age with cat allergy and moderate to severe allergic rhinitis/rhinoconjunctivitis, with or without asthma, who started allergen immunotherapy (AIT) with Dpg-pol-cat extract during routine visits to the Allergy Department. Safety and effectiveness (improvement in FEV1) of AIT were evaluated. The use of rescue medication and patient perceptions were also assessed. Results: A total of 62 patients were included, of whom 34 (54.8%) received AIT for at least 12 months. There were 15 adverse events, 8 local and 7 systemic, of which 3 led to discontinuation of AIT. Patients with moderate to severe rhinitis decreased from 88.2% at baseline to 29.4% at 12 months (p < 0.0001) and patients with moderate asthma decreased from 76.5% to 38.2% (p = 0.0004). FEV1 improved from a mean (standard deviation) of 3,188.9 (771.4) mL to 3,419.6 (878.4) mL (p = 0.0023). The use of rescue medication for rhinitis decreased from 94.1% to 23.5% (p < 0.0001). All patients requiring rescue medication for conjunctivitis (20.6%) were off medication at 12 months, and 97.1% and 92.6% of patients reported improvement in rhinitis and asthma symptoms, respectively. Conclusion: AIT with Dpg-pol-cat extract shows a favorable safety and effectiveness profile in patients with allergic rhinitis/rhinoconjunctivitis due to cat allergy, with or without allergic asthma, representing a valuable treatment option for these patients. [ABSTRACT FROM AUTHOR]

Meiosis is generally a fair process: each chromosome has a 50% chance of being included into each gamete. However, meiosis can become aberrant with some chromosomes having a higher chance of making it into gametes than others. Yet, why and how such systems evolve remains unclear. Here, we study the unusual reproductive genetics of mealybugs, where only maternal-origin chromosomes are included in gametes during male meiosis, while paternal chromosomes are eliminated. One species-Pseudococcus viburni-has a segregating B chromosome that drives by escaping paternal genome elimination. We present whole genome and gene expression data from lines with and without B chromosomes. We identify B-linked sequences including 204 protein-coding genes and a satellite repeat that makes up a significant proportion of the chromosome. The few paralogs between the B and the core genome are distributed throughout the genome, arguing against a simple, or at least recent, chromosomal duplication of one of the autosomes to create the B. We do, however, find one 373 kb region containing 146 genes that appears to be a recent translocation. Finally, we show that while many B-linked genes are expressed during meiosis, most of these are encoded on the recently translocated region. Only a small number of B-exclusive genes are expressed during meiosis. Of these, only one was overexpressed during male meiosis, which is when the drive occurs: an acetyltransferase involved in H3K56Ac, which has a putative role in meiosis and is, therefore, a promising candidate for further studies., (© The Author(s) 2025. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)