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PaNDA: Efficient Optimization of Phylogenetic Diversity in Networks.

Phylogenetic diversity (PD) plays an important role in biodiversity, conservation, and evolutionary studies by measuring the diversity of a set of taxa based on their phylogenetic relationships. In phylogenetic trees, a subset of k taxa with maximum PD can be found by a simple and efficient greedy algorithm. However, this algorithmic tractability is lost when considering phylogenetic networks, which incorporate reticulate evolutionary events such as hybridization and horizontal gene transfer. To address this challenge, we introduce PaNDA (Phylogenetic Network Diversity Algorithms), the first software package and interactive graphical user-interface for exploring, visualizing, and maximizing diversity in phylogenetic networks. PaNDA includes a novel algorithm to find a subset of k taxa with maximum diversity, running in polynomial time for networks of bounded scanwidth, a measure of tree-likeness of a network that grows slower than the well-known level measure. This algorithm considers the variant of PD on networks in which the branch lengths of all paths from the root to the selected taxa contribute towards their diversity. We demonstrate the scalability of this algorithm on simulated networks, successfully analyzing level-15 networks with up to 200 taxa in seconds. We also provide a proof-of-concept analysis using a phylogenetic network on Xiphophorus species, illustrating how the tool can support diversity studies based on real genomic data. The software is easily installable and freely available at https://github.com/nholtgrefe/panda. Additionally, we extend the definition of PD to semi-directed phylogenetic networks, which are mixed graphs increasingly used in phylogenetic analysis to model uncertainty of the root location. We prove that finding a subset of k taxa with maximum diversity remains NP-hard on semi-directed networks, but do present a polynomial-time algorithm for networks with bounded level.

network

Can't see the forest for the trees: The influence of marker type on inferred phylogenetic relationships in a cosmopolitan bat genus.

Fine-resolution information on species relationships and biological diversity is critically needed to guide conservation efforts amidst rapid environmental changes. Systematics, which forms the foundation of this knowledge, has been revolutionized by phylogenomics, utilizing genome-scale datasets. However, the use of diverse marker types, non-comparable taxon sampling, and outgroup selection can lead to conflicting phylogenetic hypotheses. These inconsistencies complicate study comparisons and hinder our ability to assess marker-specific impacts on phylogenetic resolution. The phylogenetic reconstruction of the bat genus Myotis, encompassing over 140 species and characterized by a rapid radiation in the last 20 million years, has been particularly influenced by these challenges. Achieving phylogenetic resolution in Myotis is particularly complex due to subtle interspecific differences in both morphological and molecular traits. Mitochondrial and nuclear markers often produce discordant trees, influenced by hybridization, introgression, and methodological variations. In this study, we employed a consistent taxonomic sample set of 44 Myotis taxa to evaluate the impact of five different genetic marker types on phylogenetic reconstruction. We observed significant discordance between topologies derived from conserved nuclear and mitochondrial markers and found that transposable elements were inadequate for resolving relationships across the entire genus. Our results also clarify the placement of previously problematic taxa within the genus. These findings emphasize the importance of aligning genetic marker choice with specific phylogenetic questions and highlight the influence of taxonomic and methodological variation on phylogenomic outcomes. This work provides a framework for improving phylogenetic inference in rapidly radiating groups and enhances our understanding of evolutionary history in Myotis.

Animals

Bit-reproducible parallel phylogenetic tree inference.

MOTIVATION: Phylogenetic trees describe the evolutionary history among biological species based on their genomic data. Maximum likelihood (ML) based phylogenetic inference tools search for the tree and evolutionary model that best explain the observed genomic data. Given the independence of likelihood score calculations between different genomic sites, parallel computation is commonly deployed. This is followed by a parallel summation over the per-site scores to obtain the overall likelihood score of the tree. However, basic arithmetic operations on IEEE 754 floating-point numbers, such as addition and multiplication, inherently introduce rounding errors. Consequently, the order by which floating-point operations are executed affects the exact resulting likelihood value since these operations are not associative. Moreover, parallel reduction algorithms in numerical codes re-associate operations as a function of the core count and cluster network topology, inducing different round-off errors. These low-level deviations can cause heuristic searches to diverge and induce high-level result discrepancies (e.g. yield topologically distinct phylogenies). This effect has also been observed in multiple scientific fields beyond phylogenetics. RESULTS: We observe that varying the degree of parallelism results in diverging phylogenetic tree searches (high-level results) for over 31% out of 10&#xa0;179 empirical datasets. More importantly, 8% of these diverging datasets yield trees that are statistically significantly worse than the best-known ML tree for the dataset (AU-test, P&#x2009;<&#x2009;.05). To alleviate this, we develop a variant of the widely used phylogenetic inference tool RAxML-NG, which does yield bit-reproducible results under varying core-counts, with a slowdown of only 0%-12.7% (median 0.8%) on up to 768 cores. For this, we introduce the ReproRed reduction algorithm, which yields bit-identical results under varying core-counts, by maintaining a fixed operation order that is independent of the communication pattern. ReproRed is thus applicable to all associative reduction operations-in contrast to competitors, which are confined to summation. Our ReproRed reduction algorithm only exchanges the theoretical minimum number of messages, overlaps communication with computation, and utilizes fast base-cases for local reductions. ReproRed is able to all-reduce (via a subsequent broadcast) 4.1&#xd7;106 operands across 48-768 cores in 19.7-48.61&#x2009;&#x3bc;s, thereby exhibiting a slowdown of 13%-93% over a non-reproducible all-reduce algorithm. ReproRed outperforms the state-of-the-art reproducible all-reduction algorithm ReproBLAS (offers summation only) beyond 10&#xa0;000 elements per core. In summary, we re-assess non-reproducibility in parallel phylogenetic inference, present the first bit-reproducible parallel phylogenetic inference tool, as well as introduce a general algorithm and open-source code for conducting reproducible associative parallel reduction operations. AVAILABILITY AND IMPLEMENTATION: ReproRed: https://doi.org/10.5281/zenodo.15004918 (LGPL)-Reproducible RAxML-NG version https://doi.org/10.5281/zenodo.15017407 (GPL).

Phylogeny

TreeFlow: Probabilistic Modelling and Automatic Differentiation for Phylogenetics.

Probabilistic modelling frameworks are powerful tools for statistical modelling and inference. They are not immediately generalizable to phylogenetic problems due to the particular computational properties of the phylogenetic tree object. TreeFlow is a software library for probabilistic modelling and automatic differentiation with phylogenetic trees. It embeds phylogenetic trees in the TensorFlow Probability framework, and implements inference algorithms for phylogenetic models given a fixed tree topology. We demonstrate how TreeFlow can be used to quickly implement and assess new models. We also show that it provides reasonable performance for gradient-based inference algorithms compared to specialized computational libraries for phylogenetics.

Bayesian inference

Phylogenetic Methods Meet Deep Learning.

Deep learning (DL) has been widely used in various scientific fields, but its integration into phylogenetics has been slower, primarily due to the complex nature of phylogenetic data. The studies that apply DL to sequencing data often limit analyses to four-taxon trees. Many of these studies serve as "proof of principle" and perform similarly to traditional phylogeny reconstruction methods. New ways of using training data, such as encoding with compact bijective ladderized vectors or transformers, enable the handling of much larger trees and genomic data sets. This short perspective focuses on the application of DL in phylogenetics, introducing prevalent DL architectures. We highlight potential problems in the field by discussing the risks of using simulation-based training data and emphasize the importance of reproducibility and robustness in computational estimates. Finally, we explore promising research areas, including the combination of phylogenetics and population genetics in DL, the analysis of neighbor dependencies, and the potential to significantly reduce computational cost compared to traditional methods. This perspective illustrates the potential of DL in complementing traditional phylogeny reconstruction methods and aiding the advancement of phylogenetic analysis, especially in performing computationally demanding tasks such as model selection or estimating branch support values.

Humans

Phylogenetic Constraints and Environmental Filtering Jointly Drive Adaptive Evolution in Phragmites australis: From Genetic Structure to Trait Decoupling on the Mongolian Plateau.

The Mongolian Plateau, a typical arid and semi-arid zone in Eurasia, is characterized by highly heterogeneous and fragmented wetland habitats. Phragmites australis, a common wetland species in this region, exhibits remarkable adaptability. Unraveling the coordination between phylogenetic history and local environmental filtering is crucial for elucidating its adaptive mechanisms. Integrating landscape genomics and trait-based phylogenetic analyses, we analyzed transcriptome-wide SNPs, multidimensional functional traits, and environmental variables across 90 individuals from 30 natural P. australis populations. This study aims to reveal the genetic and phenotypic variation patterns underlying population genetic structure and trait variation, specifically distinguishing the roles of geographic isolation, environmental filtering, and phylogenetic history. Results reveal a significant drainage-dependent pattern in genetic structure. Populations in hydrologically connected basins show extensive admixture, whereas those in isolated endorheic basins form distinct lineages. While geographic isolation underpins genetic differentiation, environmental filtering independently explains ~33.84% of the genetic variation, driven primarily by moisture heterogeneity (precipitation seasonality and soil moisture). Crucially, we observed differentiated evolutionary trajectories across functional traits. Structural traits (e.g., plant height, leaf thickness) are phylogenetically conserved; in contrast, physiological traits (e.g., water use efficiency) are decoupled from phylogeny, showing patterns consistent with high plasticity regulated by local environments. This evolutionary decoupling strategy enables P. australis to flexibly adapt to heterogeneous habitats while maintaining structural stability. This study uncovers the synergistic mechanisms by which geographic isolation and environmental filtering jointly shape the genetic patterns of this cosmopolitan species at a regional scale, clarifies that its evolutionary responses may depend heavily on the differentiated plasticity of trait types, and provides valuable regional insights into how widespread wetland species adapt to heterogeneous environments under global change.

Mongolia Plateau

The Complete Mitochondrial Genome of a Newly Recorded Chinese Species of Diglyphus sabulosus (Hymenoptera: Eulophidae) and Insights into Its Phylogenetic Position.

Diglyphus Walker, 1844 is an economically important genus which many species acting as biocontrol agents against agromyzid leafminer pests, but there is a lack of mitogenomic data on the evolutionary relationships within this genus, hindering a comprehensive understanding of its evolutionary history. We used traditional morphological methods to identify species, and present the first complete mitochondrial genome sequence and characterization of features of Diglyphus sabulosus and further infer its phylogenetic position based on the amino acid sequences of 13 protein-coding genes (PCGs). The complete mitochondrial genome of D. sabulosus is 15,690&#xa0;bp in length, including 13 PCGs, 22 transfer RNA genes, 2 ribosomal RNA genes and a control region. The AT content of the whole genome sequence was 81.0%, indicating a significant AT bias. All protein-coding genes have the typical ATN as the start codon and TAA as the stop codon. Phylogenetic analysis inferred from the amino acid sequences of 13 PCGs revealed that all species within the family Eulophidae constituted a monophyletic clade, supporting the monophyly of this family. D. sabulosus and D. poppoea form a well-supported sister group, representing the species with the closest phylogenetic relationship within the analyzed taxa. In this study, the mitogenome structure was analyzed and the taxonomic status of D. sabulosus was clarified, thus providing a theoretical basis for understanding the phylogenetic relationships of Diglyphus.

Animals

Comparative genomics and phylogenetic analysis of three Malvaceae species on the basis of chloroplast genomes.

INTRODUCTION: The Malvaceae family shows rich species diversity and has substantial economic and medicinal value. However, the frequent interspecific hybridization among members of this family has resulted in confused phylogenetic relationships among the groups, limiting the usefulness of traditional classification methods. METHODS: This study aimed to investigate the phylogenetic relationships among selected taxa of Malvaceae by evaluating 23 chloroplast (CP) genomes, including three newly assembled CP genomes. Among these three genomes, the CP genome of Hibiscus schizopetalus L. was reported for the first time, while the CP genomes of Alcea rosea L. and Hibiscus grewiifolius L., which have been deposited in NCBI, were re-analyzed here alongside newly generated data for comparative purposes. In addition, 20 downloaded CP genomes encompassing 13 genera were analyzed using SNPs in whole CP genomes data. RESULTS: The results showed that the genomes ranged from 160,403 to 161,978 base pairs in length and consisted of small single copies (SSCs) and large single copies (LSCs) separated by two inverted repeat sequences (IRs), forming a typical quadripartite circular structure. The entire genome sequence showed relative conservation across species in terms of structure, GC content, codon usage, and gene composition. The mutation sites were mainly located in the LSC and SSC regions, and the variability in the non-coding regions was higher than that in the coding regions. The nucleotide polymorphism (Pi) analysis identified the non-coding regions such as ndhF-rpl32 and psbZ-trnG as high variable hotspots. A maximum likelihood phylogenetic tree was constructed based on SNPs in whole CP genomes data. The phylogenetic analysis divided these 23 species into five highly supported clades. It also revealed a close sister-group relationship between Abelmoschus and Hibiscus species, suggesting that Hibiscus may have a separate lineage from okra species. DISCUSSION: In conclusion, the increasing availability of CP genome resources will enhance our understanding of the classification and evolutionary patterns of the Malvaceae family. The development of molecular markers will provide important molecular evidence for precise identification and classification revision of plants in this family.

Malvaceae

Phylogenetic inconsistency of pairwise SNP clustering for inferring tuberculosis transmission in a high-burden, endemic setting: a case study from Thailand.

Whole-genome sequence analysis is now widely used to delineate tuberculosis transmission clusters. A standard practice is to cluster bacterial isolates based on a fixed maximum genome-wide pairwise single nucleotide polymorphism (pwSNP) distance threshold. In this study, we evaluated the phylogenetic consistency of pwSNP-distance clustering with thresholds ranging between 1 and 25 single nucleotide polymorphisms (SNPs) using two contrasting data sets: (i) a data set from the UK (N = 390) published by T. M. Walker, C. L. C. Ip, R. H. Harrell, J. T. Evans, et al. (Lancet Infect Dis 13:137-146, 2013, https://doi.org/10.1016/S1473-3099(12)70277-3), which was foundational to the establishment of this method, and (ii) a data set from Thailand (N = 3,341), characterized by persistent transmission and sparse, non-systematic sampling. For the UK data set, the standard pwSNP-distance clustering using thresholds of &#x2265;12 SNPs yielded entirely monophyletic clusters and showed high concordance with a comparative monophyly constrained, tree-based method. In contrast, for the Thai data set, pwSNP-distance clustering often generated non-monophyletic clusters, even by the 25-SNP threshold. The pwSNP-distance and comparative tree-based clustering methods only showed large consistency at thresholds of &#x2265;22 SNPs. This suggests that SNP clusters defined by low distance thresholds (i.e., <12 SNPs for the UK data set, and <22 SNPs for the Thai data set) may lack robustness, and the problem is particularly severe for data sets characterized by persistent transmission, likely due to poorer cluster separation. Moreover, our findings indicate that large cluster sizes, high maximum intra-cluster genetic distances, and broad sample collection time spans may serve as useful indicators of potentially non-monophyletic clusters. We also demonstrate that mixed infections can produce spurious, phylogenetically long-range SNP linkages, underscoring the necessity of strict sequence quality control.IMPORTANCEFixed-threshold pairwise single nucleotide polymorphism (pwSNP)-distance clustering is commonly used to delineate tuberculosis transmission clusters. From an epidemiological perspective, a genuine transmission cluster must be monophyletic, originating from a single source. However, pwSNP-distance clustering is inherently simplistic and can therefore violate this principle, making the assessment of its phylogenetic consistency critical. Our results demonstrate that while this method effectively delineated complete transmission clusters for the data set from the UK, a low-burden and non-persistent transmission setting, it frequently generated non-monophyletic clusters when applied to the Thai data set, characterized by persistent transmission alongside sparse and non-systematic sampling. Furthermore, we found that clusters derived using low distance thresholds could notably vary between the pwSNP-distance and comparative tree-based clustering methods, suggesting limited reliability and robustness. To accurately delineate tuberculosis transmission clusters, especially for complex data from high-burden, endemic settings, we recommend transitioning from pwSNP-distance clustering toward more robust, phylogenetic clustering that respects evolutionary descent.

Mycobacterium tuberculosis

IQ-NET: fast and accurate quartet phylogenetic inference using deep learning trained on empirical DNA alignments.

Phylogenetic inference is fundamental to modern biology, with many applications including evolutionary biology, epidemiology, and comparative genomics. While maximum likelihood and Bayesian methods remain the gold standard for phylogenetic analysis, they rely on simplifying assumptions and are computationally intensive. Recent machine learning approaches for phylogenetics offer speed advantages, but have several limitations: exclusive reliance on simulated data for training, inadequate handling of gaps, and sensitivity to input sequence order. Here, we introduce IQ-NET (Intelligent Quartet NETwork), a deep learning framework that solves these limitations to infer four-taxon trees. IQ-NET estimates both tree topology and branch lengths directly from gapped alignments. IQ-NET outperforms existing machine learning methods in terms of accuracy, and obtained a 24-fold speedup compared with the widely used maximum likelihood software, IQ-TREE. We finally introduce a pipeline using IQ-NET and the ASTRAL software to reconstruct a larger species tree, i.e., with more than four taxa.

Empirical data training

Comparative Analysis of Chloroplast Genomes Reveals Molecular Evolution and Phylogenetic Relationships in Fraxinus (Fraxinus mandshurica).

Fraxinus mandshurica (Manchurian ash) is an ecologically and economically valuable hardwood tree native to Northeast Asia, yet its genomic resources remain limited. We assembled its complete chloroplast (cp) genome (155,559 bp) using hybrid PacBio and Illumina sequencing and performed comparative, phylogenetic, and evolutionary analyses. The cp genome exhibits a typical quadripartite structure encoding 132 gene copies, comprising 114 unique genes (80 protein-coding, 30 tRNA, and 4 rRNA genes), with 18 genes duplicated in the inverted repeat (IR) regions. Simple sequence repeat analysis revealed dominance of mononucleotide A/T repeats. Phylogenetic analysis of 53 complete cp genomes strongly supported the monophyly of Oleaceae and resolved F. mandshurica as sister to the North American F. nigra, consistent with previously proposed Miocene intercontinental dispersal scenarios between East Asia and North America. Most protein-coding genes were under strong purifying selection (Ka/Ks << 1), whereas petB, rpl2, and several ndh genes showed elevated Ka/Ks values that are suggestive of altered selective constraint but are based on very few substitutions and are therefore not, on their own, evidence of positive selection. Nucleotide diversity (Pi) analysis identified 15 hypervariable intergenic spacers (mean Pi = 0.067), among which trnM-CAU-rps14, ndhJ-ndhK, and petL-petG represent promising candidate barcode regions requiring further validation. This study provides a high-quality, fully annotated cp genome of F. mandshurica and a valuable genomic resource for future phylogenetic, population genetic, and conservation studies of this important genus.

Fraxinus

Building phenotypic character matrices for phylogenetic inference: exploration of 35&#x2009;years of practice.

Recent methodological development in phylogenetic inference has focused predominantly on molecular data. However, renewed interest in other data types, particularly morphological data, has followed from the increased recognition of the power of total evidence and tip-dating approaches, including fossil data, for inference of time-scaled trees and rates of evolution. However, attention has largely focused on the improvement of models of morphological evolution and other analytical tools with much less discussion about data acquisition itself. Here we review past and current practice for describing and collecting morphological data for phylogenetic inference. We present a systematic review of 164 phylogenetic analyses conducted over the last 35&#x2009;years and focused on a diverse group of extinct arthropods: trilobites. Trends in increasing matrix size, data type, and coding strategy are evident. Where present, polymorphic characters have been predominantly derived from discretized continuous characters, although increasingly practitioners are utilizing alternative approaches for the treatment of quantitative characters. Not surprisingly, traditional indices that describe character consistency are highly correlated with matrix size but show surprising variation at different taxonomic scales. More recent attempts to describe data quality using information theory imply that characters can have high information content even if data are missing for many tips, providing support against the exclusion of characters because of missing data. In consideration of this, as well as advances in the study of developmental biology and variational complexity, we identify several avenues for increasing the quality and quantity of morphological data going forward.

Phylogeny

Insights Into the Structural Features, Codon Usage Patterns, and Phylogenetic Analysis in Neoniphon argenteus (Teleostei: Holocentriformes) Based on Complete Mitochondrial Genome.

Neoniphon argenteus, a widely distributed nocturnal coral reef fish in the family Holocentridae, plays an important role in maintaining coral reef ecosystem health, yet its phylogenetic position remains poorly resolved. To bridge this gap, we sequenced and analyzed the complete mitochondrial genome of a specimen from the South China Sea to characterize its structural features, codon usage patterns, and phylogenetic relationships. The 16,569&#x2009;bp mitogenome (GenBank: PP190474.1) encodes 13 protein-coding genes (PCGs), 22 tRNAs, two rRNAs, and two non-coding regions, exhibiting a distinct A&#x2009;+&#x2009;T bias. All tRNAs fold into typical cloverleaf secondary structures except tRNA-Ser (AGN), which lacks the dihydrouridine (DHU) arm. The control region contains palindromic motifs (TACAT/ATGTA) capable of forming hairpin structures and five conserved sequence blocks, whereas the OL region harbors a conserved 5'-GCCGG-3' motif. RSCU analysis revealed 31 frequently used codons (RSCU >&#x2009;1) with a pronounced preference for A/C-ending codons. The &#x394;RSCU method identified 10 candidate optimal codons (GCA, CAA, GAA, GGA, AUU, CUA, CCA, CGA, ACA, and GUC). Selection pressure analysis using EasyCodeML and site-specific models indicated that all PCGs are predominantly under purifying selection, with no significant evidence of pervasive positive selection. ND6 exhibited elevated pairwise Ka/Ks ratios (mean&#x2009;=&#x2009;1.209&#x2009;&#xb1;&#x2009;0.047), consistent with reduced selective constraint rather than adaptive evolution. Phylogenetic analysis of 19 Holocentriformes species using maximum likelihood and Bayesian inference with partitioned models based on 13 PCGs and two rRNA genes (12S and 16S) assigned all taxa to two well-supported subfamilies (Holocentrinae and Myripristinae). Within Holocentrinae, Neoniphon species form a monophyletic clade nested within a paraphyletic Sargocentron, suggesting that the genus Sargocentron as currently defined is not monophyletic. This study provides useful baseline molecular data for further exploration of the evolutionary history of N. argenteus and other members of Holocentriformes.

Holocentridae

Diagnostic and phylogenetic perspectives of the 2023 Murray Valley encephalitis virus outbreak in Australia: an observational study.

BACKGROUND: An outbreak of Murray Valley encephalitis virus (MVEV), the largest since 1974, was observed in Australia between Jan 1 and July 31, 2023. This study aims to characterise the utility of diagnostic platforms, testing algorithms, and genomic characteristics of MVEV to facilitate a comprehensive framework for MVEV testing and surveillance in the outbreak setting. METHODS: In this observational study, we assessed flavivirus diagnostics for all patients with suspected Murray Valley encephalitis in Australia from Jan 1 to July 31, 2023. We included all patients with confirmed Murray Valley encephalitis, probable Murray Valley encephalitis, or acute unspecified flavivirus infection using the Communicable Diseases Network Australia case definition. Cases were excluded if an alternative diagnosis was identified. We collected blood, serum, cerebrospinal fluid, brain tissue, urine, or a combination of these samples, as appropriate and at the discretion of the treating clinician. We conducted multimodal diagnostic testing, which included flavivirus-specific serological and nucleic acid amplification testing. Metagenomic next-generation sequencing, including next-generation deep sequencing, target-enrichment, and targeted amplification, was conducted on human and representative mosquito-derived samples obtained from established mosquito population surveillance programmes for phylogenetic analysis. FINDINGS: 27 patients with encephalitis were assessed for MVEV between Jan 1, 2023, and July 31, 2023, 23 (85%) of whom fulfilled national case definitions for confirmed Murray Valley encephalitis. Patient ages ranged from 6 weeks to 83 years (median 62&#xb7;0 years [IQR 31&#xb7;0-67&#xb7;5]) and patients were mostly male (21 [78%] male patients and six [22%] female patients). Incidence varied widely by geographical region and was highest in the Northern Territory (32&#xb7;0 per 1&#x2009;000&#x2009;000 population). Diagnostic specimen collection generally occurred promptly (median 6&#xb7;0 days [IQR 4&#xb7;0-14&#xb7;5] from symptom onset to diagnostic specimen collection). In seven patients, case assignation relied on convalescent serum samples to assess for seroconversion or an appropriate rise in antibody titre (to four times the initial value or greater), or both. MVEV-specific IgM was detectable in serum samples of 17 (81%) of 21 patients tested by day 7 and MVEV IgG or total antibody (TAb) were detected in 18 (100%) of 18 patients tested by day 30. MVEV-specific IgM (or TAb) and MVEV RNA were detected in cerebrospinal fluid collected within 14 days of symptom onset in nine (39%) of 23 patients and seven (28%) of 25 patients, respectively. Phylogenetic analysis revealed two circulating MVEV genotypes, G1A and G2, in mosquitoes and humans in 2023. In southeast Australia, only G1A was detected and probably introduced from enzootic foci in northern Australia. INTERPRETATION: This study provides a comprehensive overview of the diagnostic workflows and phylogenetic evaluations used during the 2023 MVEV outbreak in Australia, emphasising the importance of a multimodal approach for accurate and timely confirmation of flavivirus infection. Further One Health surveillance for MVEV and other zoonotic flaviviruses is key, given potential expanded ecological niches in the context of episodic climatic events. FUNDING: None.

Humans

Epidemiological and phylogenetic analysis of anthrax in Kazakhstan in 2024.

BACKGROUND: Anthrax remains an important zoonotic disease in Kazakhstan due to the persistence of environmental reservoirs and long-standing endemic foci. Despite ongoing surveillance, the epidemiological characteristics and genetic diversity of circulating Bacillus anthracis strains in the country remain incompletely understood. METHODS: A retrospective epidemiological and phylogenetic investigation of anthrax outbreaks reported in Kazakhstan during 2024 was conducted. Epidemiological data were collected for all laboratory-confirmed human cases and associated outbreak foci. Confirmation of infection was performed by PCR, and B. anthracis isolates were obtained from clinical, environmental and animal-associated samples. Whole-genome sequencing and core-genome single nucleotide polymorphism (cgSNP) analysis were used to characterize the genetic relationships among isolates and to determine their phylogenetic placement. RESULTS: Nine anthrax outbreaks were identified across four regions of Kazakhstan (Almaty, Zhambyl, Atyrau, and West Kazakhstan), resulting in 20 confirmed human cases. All patients were male, with the highest proportion occurring among individuals aged 36-55&#xa0;years (45%). The mean patient age was 43.9&#xa0;years (range: 16-64&#xa0;years). Most infections were associated with slaughtering infected livestock (65%), followed by handling contaminated meat (15%). PCR confirmed infection in all 20 human cases. Culture yielded 17 human-derived B. anthracis isolates from 14 patients and 17 environmental/animal-derived isolates, resulting in 34 isolates in total. Of these, 22 representative isolates underwent whole-genome sequencing. Phylogenetic analysis revealed the circulation of two major lineages. Isolates from Atyrau and West Kazakhstan clustered within the Trans-Eurasian (TEA/STI) lineage. Atyrau isolates formed a tight cluster differing by only 21-32 cgSNPs, consistent with a shared epidemiolocal source, whereas the West Kazakhstan isolate was highly divergent. Zhambyl and Almaty region belonged to the A.Br.Ames lineage but diverged into two distinct sublineages. Zhambyl region isolates demonstrated minimal divergence from the global reference genome Ames Ancestor, differing by only 16-31 SNPs. Almaty region isolates formed an endemic subclone, separated from the reference group by approximately 114 SNPs. Comparison with the Ames Ancestor and Sterne reference strains demonstrated substantial genetic divergence. CONCLUSION: Anthrax outbreaks in Kazakhstan during 2024 were primarily associated with livestock exposure and occurred within established endemic regions. Whole-genome sequencing revealed the coexistence of distinct TEA and Ames lineages, including evidence of persistent local transmission and long-term evolutionary stability of endemic B. anthracis populations. These findings enhance understanding of anthrax epidemiology in Central Asia and support the integration of genomic surveillance into national outbreak investigation programs.

Anthrax

Genomic characterization and phylogenetic placement of Matryoshka RNA virus 1 associated with Plasmodium vivax malaria in Africa.

Plasmodium vivax is a major cause of human malaria. It harbours Matryoshka RNA virus 1 (MaRNAV-1), a bi-segmented positive-sense RNA virus. MaRNAV-1 was first described in P. vivax and is now recognized as part of a wider group of Matryoshka viruses. These viruses also infect other haemosporidian parasites such as Leucocytozoon and Haemoproteus. The presence of MaRNAV-1 in African-origin human P. vivax, however, has not been clearly established. This study investigated whether MaRNAV-1 is present in public African-origin P. vivax transcriptomic datasets. Any viral sequences recovered were characterized using comparative genomic and phylogenetic analyses. A secondary in silico analysis targeted African-origin P. vivax RNA-seq runs from public repositories. Although the search covered Africa, only Ethiopian datasets could be confidently identified, retrieved and compiled at the time. After quality control and screening for MaRNAV-1 RNA-dependent RNA polymerase (RdRp) signals, three high-confidence runs were selected for further analysis. Reference-guided reconstruction, ORF prediction, blast-based validation and RdRp phylogenetic analysis were performed. MaRNAV-1 was identified in three Ethiopian P. vivax malaria transcriptomes. This was supported by strong segment-level mapping, near-complete coverage, high mean depth and minimal low-depth masking. The recovered genomes showed the expected bisegmented organization of MaRNAV-1. Segment I was highly conserved and encoded the canonical RdRp in all three consensus sequences. Segment II showed the conserved organization of two overlapping hypothetical ORFs in all three consensus sequences. Blast analyses confirmed close similarity to MaRNAV-1 reference sequences. Phylogenetic inference grouped the Ethiopian sequences within the broader P. vivax-associated MaRNAV-1 lineage, alongside other recognized MaRNAV lineages distinct from more divergent narna-like viruses. These findings provide genomic evidence for MaRNAV-1 in publicly available African-origin P. vivax transcriptomic datasets and add to the emerging evidence for the virus in the African malaria context.

MaRNAV

Unraveling evolutionary relationships in the Sida generic alliance (Malvaceae, Malvoideae): a phylogenetic and cytotaxonomic overview.

Sida (Malvaceae), the largest Malveae-Abutilinae member, has poorly defined morphological limits which overlaps with 11 phylogenetically closely related genera that comprises the "Sida generic alliance". The 12 genera are distributed in the tropics especially in Brazil where one third of its species diversity is found. Evolutionary relationships within Sida generic alliance remain unresolved due to morphological convergence, limited taxon sampling, and lack of integrative approaches including cytogenetic data. We reconstructed the phylogeny of Sida and allied genera using a multilocus dataset (nuclear ITS and seven plastid loci) including 193 species classified in 19 genera and analyzed chromosome evolution using cytogenetic data (chromosome number) for 79 species of the 19 genera. The phylogeny recovered seven clades-Abutilon, Bakeridesia, Callianthe, Gaya, and three Sida clades (I-III)-and confirmed the polyphyly of Sida, the largest genera. We detected reticulate evolution, with incongruence between nuclear and plastid topologies. Chromosome number ranged from 2n&#xa0;=&#xa0;12 to 60 and represented synapomorphies for most clades. Ancestral character reconstruction indicated that ascending dysploidy and polyploidy predominated in karyotype evolution of Sida and allied genera. Our results reveal taxonomic incongruence in current classifications probably related to reticulate evolution. A generic-level taxonomic revision is necessary and should rely on integrated phylogenetic and karyotypic evidence. This study provides a framework for phylogenetic systematics and emphasizes the role of Brazil as a hotspot for plant genomic research.

Phylogeny

Comprehensive plastome variation and RNA editing in Mentha: insights into phylogenetic relationships and candidate DNA barcodes.

INTRODUCTION: Mentha is an economically and medicinally important genus in Lamiaceae, but its taxonomy and species delimitation remain challenging because of frequent hybridization, polyploidy, and marked morphological plasticity. METHODS: In this study, we comparatively analyzed 12 plastomes representing major Mentha species, hybrid taxa, and unresolved accessions, including four newly assembled genomes, to characterize plastome structure, repeat composition, sequence divergence, phylogenetic relationships, and plastid RNA editing. The M. arvensis plastome and RNA-seq datasets originated from independent Swiss and Indian accessions, respectively. RESULTS: The plastomes were highly conserved in overall organization, ranging from 151,824 to 152,154 bp and displaying the typical quadripartite structure. Gene content and order were largely stable across taxa, with only minor variation likely associated with annotation differences at IR/SC boundary regions. Codon usage analysis revealed a clear bias toward A/U-ending synonymous codons, and most shared protein-coding genes showed low Ka/Ks ratios, indicating predominant purifying selection. Repeat analyses showed that simple sequence repeats were mainly composed of A/T-rich mononucleotide motifs, whereas long repeats were concentrated in the 30-40 bp size class. Comparative analyses identified six hypervariable regions, namely ccsA-ndhD, ycf1, ndhD, rpl32-trnL-UAG, rbcL-accD, and petA-psbJ, which represent promising candidate plastid markers for species discrimination. Phylogenetic analysis based on complete plastomes provided strong support for relationships among the sampled taxa and recovered a close affinity among M. aquatica, M. arvensis, and M. canadensis. In addition, RNA-seq analysis of M. arvensis identified 17 candidate plastid RNA editing sites, most of which were C-to-U conversions and nonsynonymous events. DISCUSSION: Together, these results expand plastid genomic resources for Mentha and provide a useful framework for phylogenetic inference, species identification, and future germplasm utilization.

RNA editing