Search Results (14,322)

Horses were widely distributed in North America during the Pleistocene epoch and their fossil remains are common in sedimentary deposits of this age. Despite their rich fossil record, the systematics and taxonomy of North American Pleistocene horses remain unresolved. We evaluated a large sample of cranial and postcranial horse fossils of Irvingtonian and Rancholabrean North American Land Mammal Age. In this study, we present Part 1 of our evaluation, which centers on caballine horses, Equus (Equus). We present data (measurements and photographs) and analyses (Simpson’s ratio diagrams, scatter diagrams, and anatomical comparisons) that reveal morphological variation in North American caballine horses. These analyses serve as the basis for recognizing different morphospecies: E. (E.) scotti, E. (E.) alaskae, E. (E.) lambei (the latter two possibly representing “ecological variants” of a single species), E. (E.) niobrarensis, E. (E.) pacificus, and E. (E.) complicatus. How these morphospecies (or chronospecies or ecological variants) were phylogenetically related remains to be evaluated. Equus (E.) hatcheri may be considered as a morphological variant or chronological variant of E. (E.) niobrarensis. Equus holmesi is considered a junior synonym of E. (E.) scotti, while E. bautistensis may be regarded as a junior synonym of E. (E.) pacificus. Equus laurentius is a junior synonym of E. (E.) caballus, a synonymy proposed previously in other studies. We are uncertain about the nature of E. midlandensis. In addition, we identify morphometric and anatomical features that distinguish between Equus (Equus), North American Equus (Amerhippus), and Equus (Hesperohippus) mexicanus. This study aims to advance our understanding of the taxonomy of North American Pleistocene horses, providing a thoroughly documented catalogue as a basis for further studies. Full article

The Strait of Gibraltar (SG) is a key biogeographic and ecological corridor connecting the Mediterranean Sea and the Atlantic Ocean, enabling the seasonal migrations of fin whales (Balaenoptera physalus). The objective of this study was to characterize, for the first time, the spatial and temporal exposure of the species to maritime traffic during its migration through the SG, quantifying movement patterns, individual composition, and collision risk to identify critical areas for conservation. Validated observations collected between April 2016 and October 2024, with additional records in January and March 2025, were integrated with EMODnet vessel density layers to assess monthly distributions of sightings, individuals, calves, migration patterns, and behavior. A total of 347 sightings comprising 692 individuals were recorded, revealing predominantly westward movements between June and August. Spatial overlap analyses indicated that the highest exposure occurred both near the Bay of Algeciras/Gibraltar and in the northern half of the Central SG, where cargo ship and tanker traffic coincides with dense migration routes and where injuries have been documented in the field. These findings delineate high-risk areas for fin whales throughout the SG and provide an empirical basis for spatial management measures, including speed reduction zones, adaptive route planning, and the possible designation of the area as a cetacean migration corridor. The proposed measures aim to mitigate collision risk and ensure long-term ecological connectivity between the Mediterranean and the Atlantic. Full article

Spider-derived venoms are a rich source of cystine knot peptides with immense therapeutic potential. Many of these peptides exert unique biological activities through the modulation of ion channels, including of human voltage-gated sodium (Na_V1.1–Na_V1.9) channels. Na_V channel subtypes have diverse functions determined by their tissue and cellular distribution and biophysical properties, and are pathophysiology mediators in various diseases. Therefore, Na_Vs are central in studies of human biology. This work investigated the pharmacological properties of venom of the Thai theraphosid Ornithoctonus aureotibialis on Na_V channels. We discovered a predominant venom peptide named Oa1a and assessed its pharmacological properties across human Na_V channel subtypes. Synthetic forms of the peptide Oa1a showed preferential inhibition of Na_V1.1 and Na_V1.7, while recombinant Oa1a displayed a preference for inhibiting Na_V1.2, Na_V1.6, and Na_V1.7. Interestingly, all versions of Oa1a peptides exerted dual pharmacological effect by reducing the peak current and slowing fast inactivation of Na_V1.3, consistent with Oa1a having more than one binding site on Na_V channels. Such complex pharmacology was previously observed for a venom peptide in a Central American and Costa Rican tarantula, suggesting a conserved mechanism of action amongst these geographically distinct species. However, Oa1a lacked activity in the T-type channels observed in the tarantula peptide from Central America. Structure–function relationships investigated using molecular modelling showed that the dual pharmacology is driven by a conserved mechanism utilizing a mix of aromatic and charged residues, while the T-type activity appears to require additional charged residues in loop 2 and fewer positive charges in loop 4. Future structure–activity relationship studies of Oa1a will guide the development of pharmacological tools as well as next-generation drugs to treat Na_V channel dysfunction associated with neurological disorders. Full article

Amaranthus L. includes valuable and promising crops of multi-purpose use, having high morphological diversity and complicated taxonomy. Their karyotypes and genomic relationships remain insufficiently studied. For the first time, a comparative repeatome analysis of Amaranthus tricolor L., Amaranthus cruentus L., and Amaranthus hypochondriacus L. was performed based on the high-throughput sequencing data obtained via bioinformatic analyses using the RepeatExplorer2/TAREAN/DANTE_LTR pipelines. Interspecific variations in the abundance of Ty1 Copia and Ty3 Gypsy retroelements, DNA transposons, and ribosomal and satellite DNA (satDNA) were detected. Based on fluorescence in situ hybridization (FISH), chromosome mapping of 45S rDNA, 5S rDNA, and satDNAs AmC9 and AmC70, and unique karyograms of A. tricolor, A. cruentus, Amaranthus paniculatus L., and A. hypochondriacus were constructed. The analysis of the interspecies genome diversity/similarity in DNA repeat contents, sequences of the identified satDNAs, and chromosome distribution patterns of the studied molecular markers indicated that these species might also share a common evolutionary ancestor. However, the genomes of A. cruentus, A. paniculatus, and A. hypochondriacus were more similar compared to A. tricolor, which aligns with the previous phylogenetic data. Our results demonstrate that cytogenomic studies might provide important data on Amaranthus species relationships elucidating taxonomy and evolution of these valuable crops. Full article

The genus Aeromonas is widely distributed in aquatic environments, where it is a frequent fish pathogen. It has also been described in association with human infections, with most cases caused by A. caviae, A. veronii biovar sobria, and A. hydrophila. More recently, A. dhakensis has emerged as an increasingly important human pathogen. Transmission occurs primarily through ingestion or contacts with aquatic sources, or by consuming contaminated food, particularly from aquatic origins. Growing resistance in Aeromonas has been reported for penicillins (including their combinations with classical β-lactamase inhibitors), cephalosporins, and carbapenems. Among the β-lactam antibiotics, only fourth-generation cephalosporins remain almost uniformly active. Furthermore, the co-occurrence of resistance genes for third-generation cephalosporins and carbapenems within the same isolates is increasing. Recently, the presence of mobile genes conferring colistin resistance has also been documented, with resistance rates sometimes exceeding 30%. This evolution of colistin resistance is likely linked to its use in aquaculture, and together with the rise in β-lactam resistance, may be transforming Aeromonas into a significant reservoir of resistance genes that could potentially be transferred to species more commonly associated with human infections, such as the Enterobacterales. Full article

Whale sharks seasonally aggregate in Djibouti (East Africa), supporting ecotourism activities which benefit the local community. However, the environmental factors influencing whale shark relative abundance at this site are still not well understood. Environmental drivers of immature whale shark surface sightings have been analyzed across a five-year period (2017, 2020, 2022, 2024 and 2025) in the Gulf of Tadjoura (Djibouti) using a Generalized Additive Model (GAM) and Hurdle model. Across 111 surface sightings and 83 photo-identified whale sharks, both sea surface chlorophyll-a (SSC) concentrations and sea surface temperature (SST) have significantly affected their relative abundance (p < 0.001), while wind strength appeared to have a weaker and more complex effect (p < 0.05). Whale shark surface sightings in the Gulf of Tadjoura increased when SSC and SST exceeded thresholds of 0.5 mg/m⁻³ and 26 °C, respectively. In contrast, the positive effect of wind strength ≥ 7 knots was limited, indicating that wind-driven influences on whale shark surface detections are localized and transient. Since prey abundance and distribution are the main drivers of whale shark seasonal aggregations, understanding the environmental effects on food availability at coastal locations and, consequently, on whale shark surface sightings is crucial. The present study highlights temporal and seasonal trends in whale shark sighting data, contributing to broader initiatives aimed at improving conservation and management strategies for this endangered species. Full article

Background: Seed shattering enhances ecological adaptation in perennial grasses but severely limits harvestable seed yield in forage crops. Psathyrostachys juncea is an important perennial forage species in arid and cold regions, yet the genetic basis of its seed shattering remains largely unknown. Here we asked which genomic regions and biological pathways underlie natural variation in seed shattering in P. juncea, and whether cellulose synthase (CESA)-mediated cell-wall formation contributes to abscission-zone strength. Results: We evaluated seed shattering in a diverse association panel of P. juncea across four environment–-year combinations and performed a genome-wide association study (GWAS) using genotyping-by-sequencing single-nucleotide polymorphism (SNP) markers. The analysis identified 36 significant SNP loci distributed on multiple chromosomes, consistent with a highly polygenic and environment-responsive architecture. Candidate-gene annotation highlighted pathways related to cell-wall biosynthesis, hormone signaling and sugar transport. Notably, in the BT23SHT environment a cluster of association signals on chromosome 3D co-localized with several genes annotated as cellulose synthase (CESA). Abscission-zone transcriptome profiling and qRT-PCR at 7, 14, 21 and 28 days after heading revealed that CESA genes, including TraesCS3D02G010100.1 located near the lead SNP Chr3D_3539055, showed higher early expression in low-shattering lines and a decline toward baseline in high-shattering lines. Comparative analyses placed P. juncea CESA proteins within a broadly conserved but lineage-divergent framework among grasses. Conclusion: Together, these results define the genetic landscape of seed shattering in P. juncea and nominate cellulose-biosynthetic genes on chromosome 3D as promising targets for marker-assisted selection of low-shattering, high-seed-yield forage cultivars. Full article

Background: Community-onset fungemia is a clinically significant syndrome frequently linked to recent healthcare exposure and significant morbidity and mortality. Methods: We performed a 21-year, single-centre retrospective cohort of consecutive yeast bloodstream infections diagnosed at the Emergency Department (2004–2024). Clinical/epidemiological data, species identification (MALDI-TOF MS), antifungal susceptibility (CLSI M27; Sensititre YO10), and whole-genome sequencing (WGS) were analyzed. Results: Forty-eight episodes (51 isolates) were included; 56.3% were male, median age 74 years (IQR 63–82). Acquisition was healthcare-associated in 38/48 (79.2%). Sources were unknown (36.7%), abdominal (22.4%), urological (22.4%), catheter-related (14.3%), and 2.1% was attributed to a cardiovascular and a joint focus; 18.8% were polymicrobial. Crude mortality was 20.8% at 7 days (10/48) and 29.2% at 30 days (14/48). Species distribution: Candida albicans 41.2%, Nakaseomyces glabratus 27.5%, Candida parapsilosis 11.8%, Candida tropicalis 11.8%, Pichia kudriavzevii 3.9%, Clavispora lusitaniae 1.9%, and Candida orthopsilosis 1.9%. No isolate was resistant to anidulafungin, micafungin, or amphotericin B; one N. glabratus showed reduced susceptibility to caspofungin. Azole resistance was observed in one C. albicans and one N. glabratus isolate. WGS (44 isolates) confirmed MALDI-TOF identifications and characterized resistance markers. All 12 sequenced N. glabratus carried ERG2 I207V, PDR15/PDH1 E839D, and PDR1 V91I/L98S. Notable cases included one N. glabratus caspofungin-intermediate with FKS2 F659C, N. glabratus fluconazole-resistant with multiple PDR1 substitutions including a unique novel G857V, and C. albicans fluconazole-resistant harbouring alterations in MRR1/MRR2, CDR1, and ERG11. Conclusions: In this 21-year cohort, community-onset fungemia was predominantly healthcare-associated, with C. albicans as the predominant species, followed by N. glabratus. Crude mortality reached 29.2% at 30 days. Echinocandin resistance was not observed; azole resistance was uncommon. WGS provided precise speciation and actionable insight into resistance mechanisms, including a putatively novel PDR1 G857V in N. glabratus. Full article

Pecan is an important oilseed tree species valued for its nutrient-rich nuts. WRKY and VQ proteins play crucial roles in plant growth, development, and stress response. However, few WRKY and VQ genes in pecan have been functionally analyzed due to functional redundancy caused by gene duplication. In this study, 89 CiWRKYs and 47 CiVQs were identified in pecan genome, which were unevenly distributed across chromosomes. Gene structure and conserved motif analyses revealed high diversity among members. Duplication analysis indicated that segmental duplication was the major factor of family expansion of CiWRKY and CiVQ. Ka/Ks ratios revealed that most duplicated gene pairs underwent purifying selection. Promoter analysis identified numerous cis-acting elements associated with light response, hormone regulation, and abiotic stress, implying their potential regulatory roles in development and stress response. Expression data across six tissues demonstrated tissue-specific patterns, with several genes highly expressed in flowers and roots. Transcriptome analysis revealed that 63 CiWRKY and 27 CiVQ genes were significantly upregulated under drought stress. qRT-PCR validation confirmed that CiPaw.10G165200 and CiPaw.04G072500 were highly induced by salt treatment, with expression levels increasing over 100-fold at 8 d. Moreover, CiPaw.10G165200 was also highly expressed under ABA treatment, which indicated it might play a key role in the response to abiotic stresses. Our results provide valuable insights into the evolutionary patterns and functional roles of WRKY and VQ genes in pecan and lay a foundation for improving stress tolerance and molecular breeding in this economically important nut tree. Full article

The Bactrian camel is a key economic livestock species in China and around the world. It yields meat and milk (high-quality functional foods), and the milk reports health benefits. Dromedary camels, as intermediate hosts of MERS-CoV, have garnered significant public health attention. In contrast, viral surveillance in Bactrian camels from the same genus as dromedaries has received limited attention, with only sporadic or regionally confined reports available. Systematic investigations into the virome of viral species, viral diversity, and novel viruses in Bactrian camels are lacking. In this study, swabs were collected from 701 Bactrian camels in China. Through metagenomics, 3262 viral contigs were classified into 16 viral phyla, 29 viral families, and an unclassified group. The different landforms were found to influence viral diversity and composition in Bactrian camels, with mountainous area exerting the greatest impact. The viral composition significantly differed between captive and free-ranging camels. The study identified at least 12 viruses with zoonotic potential, and phylogenetic analysis indicated cross-species transmission in some of them. Additionally, picornavirus, circular Rep-encoding single-stranded (CRESS) DNA virus, and polyomavirus from Bactrian camels may represent novel species or genotypes. To summarize, in this study, we described the baseline virome profile of Chinese Bactrian camels, investigated the ecological factors influencing the viral distribution of Bactrian camels, identified key potential viral risks, and provided a scientific basis for the prevention, control, and early warning of critical viral diseases in Bactrian camels from China. Full article

Mistletoe species grow hemiparasitically on a wide spectrum of trees occurring in the tropical, subtropical and temperate zones. Mistletoe has been associated with fertility, vitality and fatality in humans. In the present review, we examine articles published in English and/or with the option to translate them into English on the distribution mechanism, ecological impact and value. This study aimed to interrogate and outline the phytonutrient profiling, ethnomedicinal and ethnopharmacological applications, toxicology and quality control of mistletoes, particularly the Loranthaceae and Viscaceae families. There are at least 1400 species of mistletoe belonging to these two families across the world. Humans have used mistletoe for years, and it has a rich history, mainly in traditional medicine. Recent research interests accompanied by investigations on mistletoe have made a major contribution to our understanding of the survival behavior and mechanisms of the species. This has prompted researchers to intensively investigate and justify its potential and applications in traditional medicine systems to further incorporate it into conventional scientific medicine processes. This study thoroughly outlines the nutritional and phytochemical constituents of various mistletoe species, as well as the factors that play a role in the process. The sections in this study dedicated to elaborating on the nutritional and phytochemical composition of mistletoe show that it is a plant species rich in nutrients and bioactive compounds, especially compared to its host. Its survival mechanism makes it possible for this plant species to contain significant quantities of both nutrients (proximate components and mineral elements) and bioactive compounds (viscin, alkaloids, phenolics and polyphenolics, tannins, flavonoids, terpenoids, glycosides, and saponins). Overall, mistletoe species have potential as medicinal plants, offering a range of health benefits and the ability to treat ailments (both communicable and non-communicable diseases). However, there are insufficient investigations and records of mistletoe’s toxicity, safety and quality control. Therefore, it is important to further investigate the potential applications, mechanisms of action, and optimal uses of mistletoe preparations and/or extracts. Full article

Thanks to their striking shapes and colors, heterobranch “sea slugs” are probably the most sought-after group of marine critters by scuba divers around the world. Nevertheless, for many of the islands and coasts of Sicily, there are no specific studies on the fauna of this group (formerly known as opisthobranchs). Even Lampedusa, one of the most famous islands in the Mediterranean, is no exception to this. To fill this knowledge gap, the authors conducted a faunal study dedicated to this group in July 2025. Data collection, carried out using the photographic-capture technique both during scuba diving and snorkeling, led to the finding of 22 species of heterobranch “sea slugs”. A comparison of the heterobranch “sea slugs” of Lampedusa with that of other Sicilian islands revealed a low diversity of these mollusks on this island. This scarcity of fauna is probably due to the lack of favorable environments and the considerable environmental homogeneity that characterizes the seabed and coastal areas of Lampedusa. Nevertheless, the discovery of some species of considerable biogeographical importance, together with the island’s unique geographical position, make it an important location to monitor for the study of the distribution patterns of allochthonous marine Heterobranchia species that enter into the Mediterranean Sea. Full article

Epichloë is a genus of endophytic fungi that forms systemic, vertically transmitted, and asymptomatic mutualistic associations with grasses in the subfamily Pooideae. These symbioses are non-pathogenic and are of considerable importance in agronomic and livestock systems due to their roles in enhancing host fitness under biotic and abiotic stress. Several studies have reported associations between Epichloë endophytes and species of the genus Bromus, a taxonomically complex group characterized by varying ploidy levels and frequent hybridization. Among its sections, Bromopsis includes the highest number of species naturally colonized by Epichloë fungi, while sections Bromus and Ceratochloa show lower infection rates. In South America, endophytes such as E. pampeana, E. tembladerae, E. typhina, and morphotypes of Neotyphodium spp. have been documented in species including B. auleticus, B. brachyanthera, and B. setifolius, where they appear to contribute to stress resilience. Although most findings originate from Argentina, significant knowledge gaps remain regarding the diversity and distribution of these endophytes in native Bromus species across the continent. This review synthesizes the current understanding of Epichloë–Bromus interactions, emphasizing their ecological and agronomic relevance, particularly in South America. Key factors influencing the establishment of these symbioses are examined, and future research directions are proposed to advance the study of these associations. Full article

Equine herpesvirus (EHV) infections represent a significant global veterinary and economic challenge affecting both horses and donkeys across all inhabited continents. This narrative review comprehensively examines the nine distinct EHV species (EHV-1 through EHV-9), their taxonomic classification within Alphaherpesvirinae and Gammaherpesvirinae subfamilies, and their diverse host tropism patterns. The complex molecular pathogenesis involves sophisticated viral glycoproteins (gK, gB, gC, gH, gM, gL, gG, gD, gI, gE) that orchestrate cellular invasion, immune evasion, and intercellular transmission. Clinical manifestations vary considerably, ranging from respiratory diseases and reproductive failures to severe neurological disorders, with EHV-1 demonstrating the most severe presentations including myeloencephalopathy. Global distribution analysis reveals widespread circulation across Europe, Asia, Africa, the Americas, and Oceania, with species-specific clinical patterns. Current therapeutic options remain largely supportive, with experimental compounds like berbamine and cepharanthine, celastrol, blebbistatin, and hyperoside showing promise in preclinical studies. Vaccination programs demonstrate limited effectiveness, failing to prevent transmission at population levels despite inducing individual immune responses. The sophisticated immune evasion strategies employed by EHVs, including the “Trojan horse” mechanism utilizing infected leukocytes, highlight the complexity of host–pathogen interactions and underscore the urgent need for innovative prevention and treatment strategies. Full article

Carotenoid pigments are widely distributed in nature and play a crucial role in protecting organisms from photodynamic damage. However, the characterization of carotenoid production in clinically relevant mycobacteria has been limited due to the low sensitivity of conventional detection methods. We present a descriptive analysis of carotenoid production in seven mycobacterial isolates from the scotochromogenic, photochromogenic, and non-chromogenic groups. To achieve this, we used a combination of High-performance liquid chromatography with diode-array detection (HPLC-DAD) and Ultra-high performance liquid chromatography–mass spectrometry (UHPLC-MS) to detect carotenoids pigments. Mycobacterium tuberculosis (MTB) and Mycobacterium bovis (MB) (non-chromogenic mycobacteria) produced β-carotene when cultured in the absence of light, at levels comparable to those of photochromogenic mycobacteria such as M. marinum (MM) and M. kansasii (MK). The highest levels of carotenoids were found in scotochromogenic species M. avium (MAV) and M. gordonae (MGOR). Conversely, M. abscessus (MABS), a non-chromogenic species in which no β-carotene was detected, served as a negative control for matrix effects. As expected, the use of highly sensitive analytical techniques such as HPLC-DAD and UHPLC-MS significantly enhanced the detection of β-carotene compared to visual pigment assessment. These methods allowed the detection of basal β-carotene levels even in mycobacteria classified as non-chromogenic. The proposed analytical approach provides a robust research tool to understand the effects of different stimulus that may alter the cell physiology in terms of pigment production. Full article