Dated phylogeny and ancestral range estimation of sand scorpions (Buthidae: Buthacus) reveal Early Miocene divergence across land bridges connecting Africa and Asia

Scorpion Venom Antimicrobial Peptide Derivative BmKn2-T5 Inhibits Enterovirus 71 in the Early Stages of the Viral Life Cycle In Vitro

Enterovirus 71 (EV71), a typical representative of unenveloped RNA viruses, is the main pathogenic factor responsible for hand, foot, and mouth disease (HFMD) in infants. This disease seriously threatens the health and lives of humans worldwide, especially in the Asia-Pacific region. Numerous animal antimicrobial peptides have been found with protective functions against viruses, bacteria, fungi, parasites, and other pathogens, but there are few studies on the use of scorpion-derived antimicrobial peptides against unenveloped viruses. Here, we investigated the antiviral activities of scorpion venom antimicrobial peptide BmKn2 and five derivatives, finding that BmKn2 and its derivative BmKn2-T5 exhibit a significant inhibitory effect on EV71. Although both peptides exhibit characteristics typical of amphiphilic α-helices in terms of their secondary structure, BmKn2-T5 displayed lower cellular cytotoxicity than BmKn2. BmKn2-T5 was further found to inhibit EV71 in a dose-dependent manner in vitro. Moreover, time-of-drug-addition experiments showed that BmKn2-T5 mainly restricts EV71, but not its virion or replication, at the early stages of the viral cycle. Interestingly, BmKn2-T5 was also found to suppress the replication of the enveloped viruses DENV, ZIKV, and HSV-1 in the early stages of the viral cycle, which suggests they may share a common early infection step with EV71. Together, the results of our study identified that the scorpion-derived antimicrobial peptide BmKn2-T5 showed valuable antiviral properties against EV71 in vitro, but also against other enveloped viruses, making it a potential new candidate therapeutic molecule.

Phylogeography of the desert scorpion illuminates a route out of Central Asia

A comprehensive understanding of phylogeography requires the integration of knowledge across different organisms, ecosystems, and geographic regions. However, a critical knowledge gap exists in the arid biota of the vast Asian drylands. To narrow this gap, here we test an "out-of-Central Asia" hypothesis for the desert scorpion Mesobuthus mongolicus by combining Bayesian phylogeographic reconstruction and ecological niche modeling. Phylogenetic analyses of one mitochondrial and three nuclear loci and molecular dating revealed that M. mongolicus represents a coherent lineage that diverged from its most closely related lineage in Central Asia about 1.36 Ma and underwent radiation ever since. Bayesian phylogeographic reconstruction indicated that the ancestral population dispersed from Central Asia gradually eastward to the Gobi region via the Junggar Basin, suggesting that the Junggar Basin has severed as a corridor for Quaternary faunal exchange between Central Asia and East Asia. Two major dispersal events occurred probably during interglacial periods (around 0.8 and 0.4 Ma, respectively) when climatic conditions were analogous to present-day status, under which the scorpion achieved its maximum distributional range. M. mongolicus underwent demographic expansion during the Last Glacial Maximum, although the predicted distributional areas were smaller than those at present and during the Last Interglacial. Development of desert ecosystems in northwest China incurred by intensified aridification might have opened up empty habitats that sustained population expansion. Our results extend the spatiotemporal dimensions of trans-Eurasia faunal exchange and suggest that species' adaptation is an important determinant of their phylogeographic and demographic responses to climate changes.

Biogeography and eye size evolution of the ogre-faced spiders

Net-casting spiders (Deinopidae) comprise a charismatic family with an enigmatic evolutionary history. There are 67 described species of deinopids, placed among three genera, Deinopis, Menneus, and Asianopis, that are distributed globally throughout the tropics and subtropics. Deinopis and Asianopis, the ogre-faced spiders, are best known for their giant light-capturing posterior median eyes (PME), whereas Menneus does not have enlarged PMEs. Molecular phylogenetic studies have revealed discordance between morphology and molecular data. We employed a character-rich ultra-conserved element (UCE) dataset and a taxon-rich cytochrome-oxidase I (COI) dataset to reconstruct a genus-level phylogeny of Deinopidae, aiming to investigate the group's historical biogeography, and examine PME size evolution. Although the phylogenetic results support the monophyly of Menneus and the single reduction of PME size in deinopids, these data also show that Deinopis is not monophyletic. Consequently, we formally transfer 24 Deinopis species to Asianopis; the transfers comprise all of the African, Australian, South Pacific, and a subset of Central American and Mexican species. Following the divergence of Eastern and Western deinopids in the Cretaceous, Deinopis/Asianopis dispersed from Africa, through Asia and into Australia with its biogeographic history reflecting separation of Western Gondwana as well as long-distance dispersal events.

Dark-colored Oncocyclus irises in Israel analyzed by AFLP, whole chloroplast genome sequencing and species distribution modeling

The Haynei is one of seven species aggregates (clusters of species having similar flower morphology) recognized in section Oncocyclus of genus Iris. This aggregate, characterized by dark-colored flowers, is represented by six species in Israel and adjacent Jordan. There is, however, no knowledge of the genetic relationship of these species making verification of their taxonomic status impossible. We investigated genetic variation in this group using analysis of whole chloroplast genomes and amplified fragment length polymorphism (AFLP). We also used species distribution modeling (SDM) to predict species ranges under current climatic conditions. We found some population groups within the currently recognized species of section Oncocyclus to represent dramatically different genetic entities which devaluates a general trend of merging many previously recognized species of section Oncocyclus based on their flower morphology. Despite the importance of homoploid hybridization in this group’s evolution and some apparently sporadically happening inter-specific gene flow, the main evolutionary forces in Oncocyclus appear to be vicariance and spatial isolation. Our findings suggest that some of the currently recognized species in section Oncocyclus need revision. A revision must be based on genetic analyses allowing the reconstruction of ancestry and recognition of the importance of vicariance and spatial isolation in the evolution of this group. The implications of the present findings for conservation are discussed.