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The genusBergiawas established by Duchassaing de Fonbressin and Michelotti in 1860, for two species,Bergia catelunarisandB. vialactea. Subsequently, in 1903 Duerden recognized these two species as conspecific, and usedB. catelunarisin favour ofB. vialactea, and transferredB. catelunaristo the genusParazoanthus. However, over the last decade, it has been found that the genusParazoanthusis actually polyphyletic and therefore it has gradually been divided and redefined. Based on phylogenetic analyses,Parazoanthus sensu strictowas recently limited to species which form associations with sponges, but it still comprised of three distinctive and monophyletic subclades. Of these clades, oneParazoanthusclade contains the type species forParazoanthus,P. axinellae, while another clade was recently described as the genusUmimayanthusbased on mitochondrial 16S-rDNA sequences. However, the other remainingParazoanthusclade containsP. catenularis, the original type species of the genusBergia. Based on a concatenated set of published data for five molecular markers (18S-rDNA, 28S-rDNA, ITS1/5.8S/ITS2-rDNA, 16S-rDNA and COI-DNA), this study confirms the monophyly ofBergiain the context of Parazoanthidae. The phylogenetic analyses strongly support the resurrection of the genusBergiaas a valid taxonomic unit. [ABSTRACT FROM PUBLISHER]

An increasing volume of empirical studies demonstrated that hybridization between distant lineages may have promoted speciation in various taxa. However, the timing, extent and direction of introgressive hybridization remain unknown in many cases. Here, we report a possible case in which repeated hybridization promoted divergence of Oryzias ricefishes (Adrianichthyidae) on Sulawesi, an island of Wallacea. Four Oryzias species are endemic to the Malili Lake system in central Sulawesi, which is composed of five tectonic lakes; of these, one lake is inhabited by two species. Morphological and population genomic analyses of genome‐wide single‐nucleotide polymorphisms revealed that these two sympatric species are phylogenetically sister to but substantially reproductively isolated from each other. Analyses of admixture and comparison of demographic models revealed that the two sympatric species experienced several substantial introgressions from outgroup populations that probably occurred soon after they had secondary contact with each other in the lake. However, the ratio of migrants from the outgroups was estimated to be different between the two species, which is consistent with the hypothesis that these introgressions aided their divergence or prevented them from forming a hybrid swarm. Repeated lake fragmentations and fusions may have promoted diversification of this freshwater fish species complex that is endemic to this ancient lake system. [ABSTRACT FROM AUTHOR]

Perhalogenated closo‐borates represent a new class of membrane carriers. They owe this activity to their chaotropicity, which enables the transport of hydrophilic molecules across model membranes and into living cells. The transport efficiency of this new class of cluster carriers depends on a careful balance between their affinity to membranes and cargo, which varies with chaotropicity. However, the structure–activity parameters that define chaotropic transport remain to be elucidated. Here, we have studied the modulation of chaotropic transport by decoupling the halogen composition from the boron core size. The binding affinity between perhalogenated decaborate and dodecaborate clusters carriers was quantified with different hydrophilic model cargos, namely a neutral and a cationic peptide, phalloidin and (KLAKLAK)2. The transport efficiency, membrane‐lytic properties, and cellular toxicity, as obtained from different vesicle and cell assays, increased with the size and polarizability of the clusters. These results validate the chaotropic effect as the driving force behind the membrane transport propensity of boron clusters. This work advances our understanding of the structural features of boron cluster carriers and establishes the first set of rational design principles for chaotropic membrane transporters. [ABSTRACT FROM AUTHOR]

Sympatric speciation has been demonstrated in few empirical case studies, despite intense searches, because of difficulties in testing the criteria for this mode of speciation. Here, we report a possible case of sympatric speciation in ricefishes of the genus Oryzias on Sulawesi, an island of Wallacea. Three species of Oryzias are known to be endemic to Lake Poso, an ancient tectonic lake in central Sulawesi. Phylogenetic analyses using RAD‐seq‐derived single nucleotide polymorphisms (SNPs) revealed that these species are monophyletic. We also found that the three species are morphologically distinguishable and clearly separated by population‐structure analyses based on the SNPs, suggesting that they are reproductively isolated from each other. A mitochondrial DNA chronogram suggested that their speciation events occurred after formation of the tectonic lake, and existence of a historical allopatric phase was not supported by coalescent‐based demographic inference. Demographic inference also suggested introgressive hybridization from an outgroup population. However, differential admixture among the sympatric species was not supported by any statistical tests. These results all concur with criteria necessary to demonstrate sympatric speciation. Ricefishes in this Wallacean lake provide a promising new model system for the study of sympatric speciation. [ABSTRACT FROM AUTHOR]

Because speciation might have been promoted by ancient introgression from an extinct lineage, it is important to detect the existence of 'ghost introgression' in focal taxa and examine its contribution to their diversification. In this study, we examined possible ghost introgression and its contributions to the diversification of ricefishes of the genus Adrianichthys in Lake Poso, an ancient lake on Sulawesi Island, in which some extinctions are known to have occurred. Population‐genomic analysis revealed that two extant Adrianichthys species, A. oophorus and A. poptae are reproductively isolated from each other. Comparisons of demographic models demonstrated that introgression from a ghost population, which diverged from the common ancestor of A. oophorus and A. poptae, is essential for reconstructing the demographic history of Adrianichthys. The best model estimated that the divergence of the ghost population greatly predated the divergence between A. oophorus and A. poptae, and that the ghost population secondarily contacted the two extant species within Lake Poso more recently. Genome scans and simulations detected a greatly divergent locus, which cannot be explained without ghost introgression. This locus was also completely segregated between A. oophorus and A. poptae. These findings suggest that variants that came from a ghost population have contributed to the divergence between A. oophorus and A. poptae, but the large time‐lag between their divergence and ghost introgression indicates that the contribution of introgression may be restricted. [ABSTRACT FROM AUTHOR]

Fully substituted peptide/[60]fullerene hexakis‐adducts offer an excellent opportunity for multivalent protein recognition. In contrast to monofunctionalized fullerene hybrids, peptide/[60]fullerene hexakis‐adducts display multiple copies of a peptide in close spatial proximity and in the three dimensions of space. High affinity peptide binders for almost any target can be currently identified by in vitro evolution techniques, often providing synthetically simpler alternatives to natural ligands. However, despite the potential of peptide/[60]fullerene hexakis‐adducts, these promising conjugates have not been reported to date. Here we present a synthetic strategy for the construction of 3D multivalent hybrids that are able to bind with high affinity the E‐selectin. The here synthesized fully substituted peptide/[60]fullerene hybrids and their multivalent recognition of natural receptors constitute a proof of principle for their future application as functional biocompatible materials. [ABSTRACT FROM AUTHOR]

We document four male colour morphs of the Indo-Pacific goby genus Lentipes in Japan and the Philippines. Despite distinctive colour patterns, males of the different morphs could not be distinguished by meristic or morphometric characters. In contrast, co-occurring females had very similar colouration and could not be sorted into different types. We observed that the four types are not distinguished by mitochondrial genome sequences. On the other hand, genome-wide SNPs analysis clearly separated the four types, suggesting that they indeed represent four independent lineages. We considered that the four lineages could have diverged recently, and therefore, the sorting of mitochondrial haplotypes may not have been completed yet. One of the four lineages is identified as L. armatus Sakai & Nakamura, 1979, and the other three are described in this study as new species: L. kijimuna sp. nov., L. bunagaya sp. nov., and L. palawanirufus sp. nov. We observed that males display their species-specific body colourations during courtship. Pre-zygotic isolation due to female preferences for different male body colours is probably the primary mechanism of reproductive isolation between the four species. [ABSTRACT FROM AUTHOR]

This paper describes the transition from the normal to inverted Marcus region in solid‐state tunnel junctions consisting of self‐assembled monolayers of benzotetrathiafulvalene (BTTF), and how this transition determines the performance of a molecular diode. Temperature‐dependent normalized differential conductance analyses indicate the participation of the HOMO (highest occupied molecular orbital) at large negative bias, which follows typical thermally activated hopping behavior associated with the normal Marcus regime. In contrast, hopping involving the HOMO dominates the mechanism of charge transport at positive bias, yet it is nearly activationless indicating the junction operates in the inverted Marcus region. Thus, within the same junction it is possible to switch between Marcus and inverted Marcus regimes by changing the bias polarity. Consequently, the current only decreases with decreasing temperature at negative bias when hopping is "frozen out," but not at positive bias resulting in a 30‐fold increase in the molecular rectification efficiency. These results indicate that the charge transport in the inverted Marcus region is readily accessible in junctions with redox molecules in the weak coupling regime and control over different hopping regimes can be used to improve junction performance. [ABSTRACT FROM AUTHOR]

Sulawesi, an island located in a biogeographical transition zone between Indomalaya and Australasia, is famous for its high levels of endemism. Ricefishes (family Adrianichthyidae) are an example of taxa that have uniquely diversified on this island. It was demonstrated that habitat fragmentation due to the Pliocene juxtaposition among tectonic subdivisions of this island was the primary factor that promoted their divergence; however, it is also equally probable that habitat fusions and resultant admixtures between phylogenetically distant species may have frequently occurred. Previous studies revealed that some individuals of Oryzias sarasinorum endemic to a tectonic lake in central Sulawesi have mitochondrial haplotypes that are similar to the haplotypes of O. eversi, which is a phylogenetically related but geologically distant (ca. 190 km apart) adrianichthyid endemic to a small fountain. In this study, we tested if this reflects ancient admixture of O. eversi and O. sarasinorum. Population genomic analyses of genome-wide single-nucleotide polymorphisms revealed that O. eversi and O. sarasinorum are substantially reproductively isolated from each other. Comparison of demographic models revealed that the models assuming ancient admixture from O. eversi to O. sarasinorum was more supported than the models assuming no admixture; this supported the idea that the O. eversi-like mitochondrial haplotype in O. sarasinorum was introgressed from O. eversi. This study is the first to demonstrate ancient admixture of lacustrine or pond organisms in Sulawesi beyond 100 km. The complex geological history of this island enabled such island-wide admixture of lacustrine organisms, which usually experience limited migration. [ABSTRACT FROM AUTHOR]

The inherent ability of peptides to self‐assemble with directional and rationally predictable interactions has fostered a plethora of synthetic two‐dimensional (2D) supramolecular biomaterials. However, the design of peptides with hierarchical assembly in different dimensions across mesoscopic lengths remains a challenging task. We here describe the structural exploration of a d/l‐alternating cyclic octapeptide capable of assembling one‐dimensional (1D) nanotubes in water, which subsequently pack laterally to form giant 2D nanosheets up to 500 μm long with a constant 3.2 nm thickness. Specific amino acid mutations allowed the mapping of structure–assembly relationships that determine 2D self‐assembly. Nine peptide modifications were studied, revealing key features in the peptide sequence that nanosheets tolerated, while a total of three peptide variants included modifications that compromised their 2D arrangement. These lessons will serve as guide and inspiration for new 2D supramolecular peptide designs. [ABSTRACT FROM AUTHOR]

Palytoxin (PLTX) is a lethal natural toxin often found in Palythoa zoantharians that, together with its congeners, may induce adverse effects in humans after inhalation of toxic aerosols both in open-air and domestic environments, namely in the vicinity of public and private aquaria. In this study, we describe a poisoning of an aquarium hobbyist who was hospitalized after handling a PLTXs-containing zoantharian hexacoral. Furthermore, we provide evidence for water detoxification. The zoantharian was morphologically and genetically identified as Palythoa cf. toxica (Cnidaria: Anthozoa). Palytoxin itself and two new PLTX congeners, a hydroxyPLTX and a deoxyPLTX, were detected and structurally identified by liquid chromatography high resolution multiple stage mass spectrometry (LC-HRMS n , n = 1, 2). Total and individual toxins were quantified by LC-HRMS and sandwich ELISA both in the zoantharian (93.4 and 96.80 μg/g, respectively) and in the transport water (48.3 and 42.56 μg/mL, respectively), with an excellent mean bias of 1.3% between the techniques. Activated carbon adsorbed 99.7% of PLTXs contained in the seawater and this represents a good strategy for preventing aquarium hobbyist poisonings. [ABSTRACT FROM AUTHOR]

Transmembrane ion exchange controls biological functions and is essential for life. Over the years, a great variety of nature-inspired artificial ion channels and carriers have been synthesized to control and promote ion exchange across biological membranes. In this context, peptides emerged as ideal scaffolds for synthetic ion channels due to their biocompatibility, accessibility and chemical versatility. Peptides have already shown their potential for the construction of a range of synthetic ion transporters either alone or in combination with other molecular scaffolds. Among the great diversity of peptide-based ion transporters, we can find key examples of single-molecule and supramolecular transmembrane ion channels and ionophores. Peptide scaffolds have also found great potential for the transmembrane delivery of biomolecular cargos such as nucleic acids and proteins. This review covers some of the most relevant advances in the peptide-based ion transport field from the last few years., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Left bundle branch area pacing (LBBAP) needs confirmation of left conduction system capture assessed by testing of different electrical parameters. Guidelines recommend the use of an electrophysiology recording system (EP-RS) to guide conduction system pacing procedures. However, some experienced centers perform LBBAP procedures without an EP-RS., Objective: We aimed to assess whether LBBAP criteria can be measured by the signals provided by the pacing system analyzers (PSAs) as a surrogate for the EP-RS to simplify and universalize the technique., Methods: This was an observational, prospective, multicenter study assessing the current LBBAP criteria using the PSA compared with the EP-RS during conduction system pacing procedures., Results: A consecutive 108 patients were included. Baseline QRS duration was 130 ± 29 ms in the EP-RS vs 128 ± 29 ms in the PSA (P = .7). An initial W morphology in V 1 was noted in 88% of patients with the EP-RS vs 86% of patients with the PSA (P = .7) during unipolar pacing. The QRS duration (122 ± 17 ms vs 123 ± 19 ms; P = .7), the R-wave peak time interval in V 6 (80 ± 13 ms vs 79 ± 14 ms (P = .9), and the V 6 -V 1 interpeak interval (39 ± 16 ms vs 38 ± 17 ms (P = .7) were superimposable in the EP-RS compared with the PSA. Pearson coefficients for the last 2 criteria were 0.85 (P < .0001) and 0.94 (P < .0001), respectively. According to the current criteria, 91.5% of patients received a successful LBBAP implant using the EP-RS. Based on the PSA measurements, 96.6% of these patients met LBBAP criteria., Conclusion: Criteria for LBBAP can be assessed by PSAs with high accuracy. These results provide the basis for the usefulness of the PSA to guide LBBAP procedures., Competing Interests: Disclosures Pau Cosialls Guillen is an Abbott medical engineer. Aitor Toledo Silva is a Boston Scientific engineer. Carolina López Reitmaier is a Medtronic engineer., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

As in natural cytoskeletons, the cooperative assembly of fibrillar networks can be hosted inside compartments to engineer biomimetic functions, such as mechanical actuation, transport, and reaction templating. Coacervates impose an optimal liquid-liquid phase separation within the aqueous continuum, functioning as membrane-less compartments that can organise such self-assembling processes as well as the exchange of information with their environment. Furthermore, biological fibrillation can often be controlled or assisted by intracellular compartments. Thus, the reconstitution of analogues of natural filaments in simplified artificial compartments, such as coacervates, offer a suitable model to unravel, mimic, and potentially exploit cellular functions. This perspective summarises the latest developments towards assembling fibrillar networks under confinement inside coacervates and related compartments, including a selection of examples ranging from biological to fully synthetic monomers. Comparative analysis between coacervates, lipid vesicles, and droplet emulsions showcases the interplay between supramolecular fibres and the boundaries of the corresponding compartment. Combining inspiration from natural systems and the custom properties of tailored synthetic fibrillators, rational monomer and compartment design will contribute towards engineering increasingly complex and more realistic artificial protocells., (© 2024. The Author(s).)

The structure of helical polymers is dictated by the molecular chirality of their monomer units. Particularly, macromolecular helices with monomer sequence control have the potential to generate chiral topologies. In α-helical folded peptides, the sequential repetition of amino acids generates a chiral layer defined by the amino acid side chains projected outside the amide backbone. Despite being closely related to peptides' structural and functional properties, to the best of our knowledge, a general exo-helical symmetry model has not been yet described for the α-helix. Here, we perform the theoretical, computational, and spectroscopic elucidation of the α-helix principal exo-helical topologies. Non-canonical labeled amino acids are employed to spectroscopically characterize the different exo-helical topologies in solution, which precisely match the theorical prediction. Backbone-to-chromophore distance also shows the expected impact in the exo-helices' geometry and spectroscopic fingerprint. Theoretical prediction and spectroscopic validation of this exo-helical topological model provides robust experimental evidence of the chiral potential on the surface of helical peptides and outlines an entirely new structural scenario for the α-helix., (© 2024. The Author(s).)