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MicroRNAs (miRNAs) function cell-intrinsically to regulate gene expression by base-pairing to complementary mRNA targets while in association with Argonaute, the effector protein of the miRNA-mediated silencing complex (miRISC). A relatively dilute population of miRNAs can be found extracellularly in body fluids such as human blood plasma and cerebrospinal fluid (CSF). The remarkable stability of circulating miRNAs in such harsh extracellular environments can be attributed to their association with protective macromolecular complexes, including extracellular vesicles (EVs), proteins such as Argonaut 2 (AGO2), or high-density lipoproteins. The precise origins and the potential biological significance of various forms of miRNA-containing extracellular complexes are poorly understood. It is also not known whether extracellular miRNAs in their native state may retain the capacity for miRISC-mediated target RNA binding. To explore the potential functionality of circulating extracellular miRNAs, we comprehensively investigated the association between circulating miRNAs and the miRISC Argonaute AGO2. Using AGO2 immunoprecipitation (IP) followed by small-RNA sequencing, we find that miRNAs in circulation are primarily associated with antibody-accessible miRISC/AGO2 complexes. Moreover, we show that circulating miRNAs can base-pair with a target mimic in a seed-based manner, and that the target-bound AGO2 can be recovered from blood plasma in an ∼1:1 ratio with the respective miRNA. Our findings suggest that miRNAs in circulation are largely contained in functional miRISC/AGO2 complexes under normal physiological conditions. However, we find that, in human CSF, the assortment of certain extracellular miRNAs into free miRISC/AGO2 complexes can be affected by pathological conditions such as amyotrophic lateral sclerosis.

The return voyage of the Argonauts described in the Library presents remarkable differences compared to the model provided by Apollonius of Rhodes. Here we focus specifically on two aspects of the trip in Apollodorus's version, with the aim of providing new insights on these elements of the story that deviate from Apollonius: the order of the stages in the Adriatic Sea and the absence of the Libyan episode. As a result, our analysis allows us to appreciate, beyond the canonical value acquired by Apollonius's text in the early imperial period, the important role played by other local myths, even glimpsing the influence of more ancient traditions about the journey of the Argonauts. Moreover, Apollodorus' authorial choices seem to reveal a general scepticism for the part of the mythographer regarding the possibility of adapting the landscape of the mythological traditions to the geographical knowledge of his time.

Argonauts or paper nautiluses are pelagic octopod cephalopods with a cosmopolitan distribution in tropical and subtropical waters around the world. Unlike other species of octopus, these are characterized by the fact that the female has a shell that serves as the breeding chamber for the eggs. Over time, this structure has been used as a taxonomic diagnostic character, causing problems in the systematics of this genus, with around 50 synonymies reported. Only two species, Argonauta argo and A. nouryi, have been reported in the Northern Humboldt Current System; however, there is taxonomic uncertainty regarding these species, which is reflected in the paralarvae (the first stage of life after hatching). In the paralarvae, the chromatophore patterns are considered to be conservative and reliable taxonomic characteristics. The objective of this study is to demonstrate the extensive variability in the chromatophore arrangement of Argonauta paralarvae in the Northern Humboldt Current using DNA barcoding and five species delimitation models. Our results include up to 11 different paralarvae morphotypes according to the pattern of chromatophores (number and arrangement) and 2 shell morphotypes. Species delimitation methods divided the 13 Argonauta morphotypes into two consensus molecular taxonomic units (MOTUs), A. argo and A. nouryi. Additionally, the results revealed an extensive morphological variability in the paralarvae and female shells of A. nouryi, demonstrating the importance of molecular data in studies involving species with different life stages, especially when this extensive morphological variability obscures conventional analyses.

Argonauta argo (Linnaeus, 1758), commonly known as the greater argonaut, is a pelagic octopod with a circumglobal distribution in warm and temperate seas. Although the species is occasionally reported in the Mediterranean Sea, confirmed in situ observations of live individuals remain scarce, particularly in the eastern basin. Here, we document the occurrence of a live female A. argo entangled in aquaculture nets at a sea bass (Dicentrarchus labrax) facility off the coast of Lesvos Island in the northeastern Aegean Sea, Greece. This represents the first confirmed observation in this part of the Mediterranean and only the second confirmed observation of a live individual in Greek waters. The individual was photographed in situ and identified based on diagnostic morphological features. The encounter occurred under specific hydrodynamic and environmental conditions potentially favorable to the species, including enhanced prey availability and structural refuge within the aquaculture infrastructure. This record contributes to the limited dataset on Mediterranean argonauts and underscores the need for further research into their ecology, distribution patterns, and potential interactions with anthropogenic marine structures.

Eukaryotic cells use guided search to coordinately control dispersed genetic elements. Argonaute proteins and their small RNA cofactors engage nascent RNAs and chromatin-associated proteins to direct transcriptional silencing. The small ubiquitin-like modifier (SUMO) has been shown to promote the formation and maintenance of silent chromatin (called heterochromatin) in yeast, plants, and animals. Here, we show that Argonaute-directed transcriptional silencing in Caenorhabditis elegans requires SUMOylation of the type 1 histone deacetylase HDA-1. Our findings suggest how SUMOylation promotes the association of HDAC1 with chromatin remodeling factors and with a nuclear Argonaute to initiate de novo heterochromatin silencing.

Background Numerous DNA-damaging cellular stresses, including oncogene activation and DNA-damage response (DDR), may lead to cellular senescence. Previous observations linked microRNA deregulation with altered senescent patterns, prompting us to investigate whether epigenetic repression of microRNAs expression might disrupt senescence in prostate cancer (PCa) cells. Methods Differential methylation mapping in prostate tissues was carried using Infinium HumanMethylation450 BeadChip. After validation of methylation and expression analyses in a larger series of prostate tissues, the functional role of the cluster miR-130b~301b was explored using in vitro studies testing cell viability, apoptosis, invasion and DNA damage in prostate cancer cell lines. Western blot and RT-qPCR were performed to support those observations. Results We found that the miR-130b~301b cluster directs epigenetic activation of cell cycle inhibitors required for DDR activation, thus stimulating the senescence-associated secretory phenotype (SASP). Furthermore, overexpression of miR-130b~301b cluster markedly reduced the malignant phenotype of PCa cells. Conclusions Altogether, these data demonstrate that miR-130b~301b cluster overexpression might effectively induce PCa cell growth arrest through epigenetic regulation of proliferation-blocking genes and activation of cellular senescence.

This volume on Apollonius of Rhodes, whose Argonautica is the sole full-length epic to survive from the Hellenistic period, comprises articles by fourteen leading scholars from Europe and America.Their contributions cover a wide range of issues from the history of the text and the problems of the poet's biography through questions of style, literary technique and intertextual relations to the epic's literary and cultural reception.The aim is to give an up-to-date outline of the scholarly discussion in these areas and to provide a survey of recent and current trends in Apollonian studies which will be useful to students of Hellenistic poetry in general as well as to scholars with a specialised interest in Apollonius.

We explore the relationship between network role, territorial location and the adoption of transgressive styles on jazz music between 1950 and 1969. Our study contributes to the literature on the role of networks in the adoption of innovations, employing the following analytic strategies: (1) we use regular equivalence to identify clusters hierarchically related to each other; (2) classify these clusters into role types; (3) we determine the extent to which territory moderates the relationship between role and the adoption of innovation and (4) we show that territorial location and mobility emerge as an alternative mechanism to network role.

Molluscs are known for their ability to produce a calcified shell resulting from a genetically controlled and matrix-mediated process, performed extracellularly. The occluded organic matrix consists of a complex mixture of proteins, glycoproteins and polysaccharides that are in most cases secreted by the mantle epithelium. To our knowledge, the model studied here—the argonaut, also called paper nautilus—represents the single mollusc example where this general scheme is not valid: the shell of this cephalopod is indeed formed by its first dorsal arms pair and it functions as an eggcase, secreted by females only; furthermore, this coiled structure is fully calcitic and the organization of its layered microstructures is unique. Thus, the argonautid shell appears as an apomorphy of this restricted family, not homologous to other cephalopod shells. In the present study, we investigated the physical and biochemical properties of the shell of Argonauta hians, the winged argonaut. We show that the shell matrix contains unusual proportions of soluble and insoluble components, and that it is mostly proteinaceous, with a low proportion of sugars that appear to be mostly sulfated glycosaminoglycans. Proteomics performed on different shell fractions generated several peptide sequences and identified a number of protein hits, not shared with other molluscan shell matrices. This may suggest the recruitment of unique molecular tools for mineralizing the argonaut’s shell, a finding that has some implications on the evolution of cephalopod shell matrices.

This article analyses Euripides’ mythopoetics in what survives of the first quarter of his fragmentary Hypsipyle: prologue, parodos, and first episode. It examines Euripides’ innovation in joining two myths (the Seven Against Thebes and the story of Hypsipyle and the Argonauts) into one, and the representation of Hypsipyle herself. In her private moments, the thoughts that preoccupy her mind are focused on other-places and other-times, in vivid contrast to the naturalistically presented world of the present where, as a slave, she must interact with men. Euripides uses the language of serving (θɛραπɛύɛιν) and doing a ‘favour’ (χάρις), as well as the word ἐρῆμος (‘lonely,’ ‘deserted’) and homoeophonic language (e.g. Argo and Argos) to indicate that, in helping the Argives, Hypsipyle repeats typologically her hospitality to the Argonauts. There is a circularity in Hypsipyle's story that creates suspense, since by doing a favour for the Argive leader, she is reunited with the sons she bore to Argonauts’ leader, who themselves are sent to find her by their grandfather whom she saved; and by losing the infant in her care (Opheltes, later named Archemorus), she is reunited with her former infants. By the end of Hypsipyle's first conversation with Amphiaraus, Euripides has invented a theme of ‘parallel worlds’ that he will resolve at the play's end.