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Abstract Transposable elements (TEs) are dynamic components of eukaryotic genomes that are important in speciation. Evolutionary pressure has led to the evolution of silencing mechanisms, such as the involvement of Krüppel box-associated zinc finger proteins (KRAB-ZFPs) that regulate TE transcription via TRIM28-mediated NuRD complex recruitment in sarcopterygians. The transcriptional activity of genes that encode proteins of the NuRD complex was also detected in actinopterygians, even though genes encoding crucial proteins such as TRIM28 and KRAB-ZNF are missing in this evolutionary lineage. This study hypothesized that TRIM33 could serve as a replacement for TRIM28 in this lineage and suggested an evolutionary relationship between the sarcopterygian KRAB-ZFPs, the actinopterygian KRAB-like ZNFs and the fish N-terminal zinc-associated domain (FiNZ) ZNFs that are specific to cyprinids. Through coimmunoprecipitation analyses conducted in the basal teleost Anguilla marmorata and the cyprinid Danio rerio, we evaluated the interaction of TRIM33 with the KRAB-like and FiNZ ZFPs. Moreover, we explored the expression profiles of TEs and genes that encode proteins that are potentially involved in their silencing during zebrafish development. Our results may provide new evidence for more thoroughly understanding the evolutionary mechanisms underlying the adaptation of ray-finned fish.

Onopordum tauricum Willd., a species distributed in Eastern Europe, has been the subject of various research endeavors aimed at assessing its suitability for extracting vegetable rennet for use in the production of local cheeses as a substitute for animal-derived rennet. In Italy, the species has an extremely fragmented and localized distribution in six locations scattered across the central-northern Apennines and some areas of southern Italy. In this study, both the morphology and genetic diversity of the six known Italian populations were investigated to detect putative ecotypes. To this end, 33 morphological traits were considered for morphometric measurements, while genetic analysis was conducted on the entire genome using the ddRAD-Seq method. Both analyses revealed significant differences among the Apennine populations (SOL, COL, and VIS) and those from southern Italy (ROT, PES, and LEC). Specifically, the southern Italian populations appear to deviate significantly in some characteristics from the typical form of the species. Therefore, its attribution to O. tauricum is currently uncertain, and further genetic and morphological analyses are underway to ascertain its systematic placement within the genus Onopordum.

Cette contribution propose un aperçu des principales modifications législatives et de la jurisprudence du Tribunal fédéral [TF] de l'année 2021 en droit suisse des sociétés. La section consacrée aux modifications législatives (chiffre I) revient sur l'entrée en vigueur des modifications du CO et d'autres lois relatives au droit commercial tandis que les résumés de jurisprudence font l'objet de la section suivante (chiffre II) ; les arrêts y sont classés par forme de société et les arrêts publiés au recueil des ATF précèdent les autres arrêts, qui sont classés par ordre chronologique. -- Dieser Beitrag bietet einen Überblick über die wichtigsten Gesetzesänderungen und die Rechtsprechung des Bundesgerichts für das Jahr 2021 im Schweizer Gesellschaftsrecht. Der Abschnitt über die Gesetzesänderungen (Ziffer I) geht auf das Inkrafttreten der Änderungen des OR und anderer handelsrechtlicher Gesetze ein, während die Zusammenfassungen der Rechtsprechung Gegenstand des darauffolgenden Abschnitts (Ziffer II) sind. Die Urteile sind dort nach Gesellschaftsform geordnet und die in der amtlichen Sammlung des Bundesgerichts publizierten Leitentscheide (BGE) gehen den anderen Urteilen, die chronologisch geordnet sind, voraus.

Abstract Caudata is an order of amphibians with great variation in genome size, which can reach enormous dimensions in salamanders. In this work, we analysed the activity of transposable elements (TEs) in the transcriptomes obtained from female and male gonads of the Chinese fire-bellied newt, Cynops orientalis, a species with a genome about 12-fold larger than the human genome. We also compared these data with genomes of two basal sarcopterygians, coelacanth and lungfish. In the newt our findings highlighted a major impact of non-LTR retroelements and a greater total TE activity compared to the lungfish Protopterus annectens, an organism also characterized by a giant genome. This difference in TE activity might be due to the presence of young copies in newt in agreement also with the increase in the genome size, an event that occurred independently and later than lungfish. Moreover, the activity of 33 target genes encoding proteins involved in the TE host silencing mechanisms, such as Ago/Piwi and NuRD complex, was evaluated and compared between the three species analysed. These data revealed high transcriptional levels of the target genes in both newt and lungfish and confirmed the activity of NuRD complex genes in adults. Finally, phylogenetic analyses performed on PRDM9 and TRIM28 allowed increasing knowledge about the evolution of these two key genes of the NuRD complex silencing mechanism in vertebrates. Our results confirmed that the gigantism of the newt genomes may be attributed to the activity and accumulation of TEs.

The nucleotype theory has been advanced on the basis of studies regarding genome size and composition in various plant and animal species, i.e. the influence that genome can have on the phenotype independently of the informational content of DNA. It has also been noted that during evolution various interactions between different environmental factors and genome structural and functional parameters would have occurred. In this review, changes in genome size, transposon content, and base composition occurred during the evolution of chordates were examined. Many environmental stresses, such as temperature, can act on transposons and through these on genome size. Temperature is also one of the most important elements of natural selection able to interact both with base composition and genome size. It has been evidenced that temperature exerts a direct influence on base composition and its increase would have led to an higher content of genome GC-rich components during the evolution of chordates, in particular in endotherms. Temperature would have controlled the rate of biosynthesis in G1 phase and consequently the cell cycle duration which in turn would have interacted with genome size. The combined action of temperature, base composition, and genome size would also have been very important in controlling the metabolic rate. Finally, another important aspect of the nucleotypic effect is the influence that genome size and cell cycle duration, in correlation with environmental temperature, would have exert on embryo and larval development, very important for environmental adaptation. In conclusion, studies here reviewed to confirm the existence in chordates of a mutual influence between environment and genome non-coding components that would have played an important role in the evolution of these animals especially in environmental adaptation processes.

Ray-finned fish represent a very interesting group of vertebrates comprising a variety of organisms living in different aquatic environments worldwide. In the case of stenothermal fish, thermal fluctuations are poorly tolerated, thus ambient temperature represents a critical factor. In this paper, we considered the tiger barb Puntius tetrazona, a freshwater fish belonging to the family Cyprinidae, living at 21–28 °C. We analyzed the available RNA-Seq data obtained from specimens exposed at 27 °C and 13 °C to investigate the transcriptional activity of transposable elements (TEs) and genes encoding for proteins involved in their silencing in the brain, gill, and liver. TEs are one of the tools generating genetic variability that underlies biological evolution, useful for organisms to adapt to environmental changes. Our findings highlighted a different response of TEs in the three analyzed tissues. While in the brain and gill, no variation in TE transcriptional activity was observed, a remarkable increase at 13 °C was recorded in the liver. Moreover, the transcriptional analysis of genes encoding proteins involved in TE silencing such as heterochromatin formation, the NuRD complex, and the RISC complex (e.g., AGO and GW182 proteins) highlighted their activity in the hepatic tissue. Overall, our findings suggested that this tissue is a target organ for this kind of stress, since TE activation might regulate the expression of stress-induced genes, leading to a better response of the organism to temperature changes. Therefore, this view corroborates once again the idea of a potential role of TEs in organism rapid adaptation, hence representing a promising molecular tool for species resilience.

Cette contribution propose un aperçu des principales modifications législatives intervenues durant l’année 2020 en droit suisse des sociétés, ainsi que de la jurisprudence du Tribunal fédéral rendue pendant la même période. La section consacrée aux modifications législatives (chiffre I.) présente en particulier, de manière succincte, la modification du droit de la société anonyme [SA] adoptée le 19 juin 2020. Les résumés de jurisprudence font l’objet de la section suivante (chiffre II.) ; les arrêts sont classés par forme de société. Après la présentation des arrêts publiés au recueil des ATF, les arrêts sont classés par ordre chronologique. -- Dieser Beitrag bietet einen Überblick über die wichtigsten Gesetzesänderungen im Schweizer Gesellschaftsrecht im Jahr 2020 sowie über die bundesgerichtliche Rechtsprechung im selben Zeitraum. Der Abschnitt über Gesetzesänderungen stellt die am 19. Juni 2020 verabschiedete Änderung der Bestimmungen zur Aktiengesellschaft (AG) dar. Der nächste Abschnitt enthält Zusammenfassungen der Rechtsprechung, wobei die Entscheidungen nach Gesellschaftsform geordnet sind. Nach der Vorstellung der in der amtlichen BGE-Sammlung veröffentlichten Entscheide werden die übrigen Urteile in chronologischer Reihenfolge aufgeführt.

The vitellogenin gene family is constituted of variable gene numbers encoding for polypeptides that are precursors of yolk proteins and derivatives in oviparous and ovoviviparous vertebrates. The comprehension of which mechanisms have shaped the evolution of vtg gene family represents an attractive field of research. The primary intent of this review is to summarize the evolutionary hypotheses that have been proposed over recent decades, highlighting the differences between the proposed models. Overall in vertebrates the evolutionary history of this gene family is the result of complex modifications deeply influenced by events such as Whole Genome Duplications (WGDs), lineage-specific gene losses and duplications. Interestingly the last hypothesis allowed to date the vitellogenin gene cluster origin in the common ancestor of gnathostomes. In addition, in the last decades, several works evidenced non-nutritional functions such as antibacterial, immunological and antioxidant activities overcoming its classical view as a simple source of nourishment for the developing embryos.

The evolutionary success of species is strictly related to their genome in terms of composition and functionality. Transposable elements (TEs) represent a considerable fraction of the nuclear DNA content, and given to their ability to spread throughout the genome, they are able to create genetic diversity at sequence, gene structure, and chromosome level. Vertebrates represent a highly successful taxon and its lineages are characterized by a variable TE content suggesting a different impact on the genome. In this manuscript, we highlight the importance of TEs in creating new regulatory sequences and genetic innovations extremely useful for diversification of vertebrates. Moreover, an increasing number of evidence suggests a link between TEs and environment. Indeed, given the richness of species adapted to a wide range of habitats and conditions, vertebrates are exposed to several ecological pressures with consequent effects on evolutionary adaptation.

The striped venus Chamelea gallina is a bivalve mollusc that represents one of the most important fishery resources of the Adriatic Sea. In this work, we investigated for the first time the ability of this species to modulate the expression of genes encoding proteins involved in biomineralization process in response to biotic and abiotic factors. We provided the first comprehensive transcriptome from the mantle tissue of clams collected in two sampling sites located along the Italian Adriatic coast and characterized by different environmental features. Moreover, the assessment of environmental parameters, scanning electron microscopy (SEM), and X-ray diffraction (XRD) measurements on valves were conducted to better contextualize RNA sequencing (RNA-Seq) data. Functional annotation of differentially expressed genes (DEGs) and SEM observations highlighted a different shell mineralization behaviour in C. gallina clams collected from two selected sites characterized by diverse environmental parameters.

Cette contribution propose un aperçu des principales modifications législatives intervenues durant l’année 2019 en droit suisse des sociétés, ainsi que de la jurisprudence du Tribunal fédéral [TF] rendue et des ouvrages de doctrine (commentaires de lois, monographies, thèses et articles d’ouvrages collectifs) publiés dans ce domaine pendant la même période. La section consacrée aux modifications législatives (ch. I.) présente l’état, au 31 décembre 2019, de la modification projetée du droit de la société anonyme [SA] et les modifications récentes en matière d’actions au porteur. Les résumés de jurisprudence font l’objet de la section suivante (ch. II.) ; les arrêts sont classés par forme de société. Après la présentation des arrêts publiés au recueil des ATF, les arrêts sont classés par ordre chronologique. Le recensement par thème des ouvrages de doctrine parus en 2019 conclut l’article (ch. III.).

Cette contribution propose un aperçu, pour l’année 2018, des principales modifications législatives, de la jurisprudence du Tribunal fédéral [TF] et des ouvrages de doctrine publiés en droit suisse des sociétés. La section consacrée aux modifications législatives (I.) présente principalement les derniers développements de la modification projetée du droit de la société anonyme [SA]. Les résumés de jurisprudence font l’objet de la section suivante (II.). Finalement, les ouvrages de doctrine (III.) sont recensés par thème.

Ray-finned fishes (Actinopterygii) are a very diverse group of vertebrates, encompassing species adapted to live in freshwater and marine environments, from the deep sea to high mountain streams. Genome sequencing offers a genetic resource for investigating the molecular bases of this phenotypic diversity and these adaptations to various habitats. The wide range of genome sizes observed in fishes is due to the role of transposable elements (TEs), which are powerful drivers of species diversity. Analyses performed to date provide evidence that class II DNA transposons are the most abundant component in most fish genomes and that compared to other vertebrate genomes, many TE superfamilies are present in actinopterygians. Moreover, specific TEs have been reported in ray-finned fishes as a possible result of an intricate relationship between TE evolution and the environment. The data summarized here underline the biological interest in Actinopterygii as a model group to investigate the mechanisms responsible for the high biodiversity observed in this taxon.

La contribution présente, sous une forme synthétique, les principales modifications législatives, entrées en vigueur et en cours, la jurisprudence ainsi que la doctrine publiée en droit suisse des sociétés en 2017. Les modifications législatives (I.) accordent une large place à la présentation de la révision projetée du droit de la société anonyme, tout en s’intéressant également à d’autres thèmes, tel que l’initiative populaire « Entreprises responsables - pour protéger l’être humain et l’environnement ». Les résumés de jurisprudence sont classés par forme de société et décrivent en premier lieu les arrêts publiés (II.). Finalement, la doctrine est présentée en fonction du thème traité (III.).

Repetitive DNA represents the major component of the genome in both plant and animal species. It includes transposable elements (TEs), which are dispersed throughout the genome, and satellite DNAs (satDNAs), which are tandemly organized in long arrays. The study of the structure and organization of repetitive DNA contributes to our understanding of genome architecture and the mechanisms leading to its evolution. Molluscs represent one of the largest groups of invertebrates and include organisms with a wide variety of morphologies and lifestyles. To increase our knowledge of bivalves at the genome level, we analysed the Antarctic scallop Adamussium colbecki. The screening of the genomic library evidenced the presence of two novel satDNA elements and the CvA transposon. The interspecific investigation performed in this study demonstrated that one of the two satDNAs isolated in A. colbecki is widespread in polar molluscan species, indicating a possible link between repetitive DNA and abiotic factors. Moreover, the transcriptional activity of CvA and its presence in long-diverged bivalves suggests a possible role for this ancient element in shaping the genome architecture of this clade.