SEARCH · Search PubMed

Results for “phylogenetic analyses”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed2022

Spatial-temporal and phylogenetic analyses of epidemiologic data to help understand the modes of transmission of endemic typhoid fever in Samoa.

Salmonella enterica serovar Typhi (S. Typhi) is either widely distributed or proximally transmitted via fecally-contaminated food or water to cause typhoid fever. In Samoa, where endemic typhoid fever has persisted over decades despite water quality and sanitation improvements, the local patterns of S. Typhi circulation remain unclear. From April 2018-June 2020, epidemiologic data and GPS coordinates were collected during household investigations of 260 acute cases of typhoid fever, and 27 asymptomatic shedders of S. Typhi were detected among household contacts. Spatial and temporal distributions of cases were examined using Average Nearest Neighbor and space-time hotspot analyses. In rural regions, infections occurred in sporadic, focal clusters contrasting with persistent, less clustered cases in the Apia Urban Area. Restrictions to population movement during nationwide lockdowns in 2019-2020 were associated with marked reductions of cases. Phylogenetic analyses of isolates with whole genome sequences (n = 186) revealed one dominant genotype 3.5.4 (n = 181/186) that contains three Samoa-exclusive sub-lineages: 3.5.4.1, 3.5.4.2, and 3.5.4.3. Variables of patient sex, age, and geographic region were examined by phylogenetic groupings, and significant differences (p<0.05) associated genetically-similar isolates in urban areas with working ages (20-49 year olds), and in rural areas with age groups typically at home (<5, 50+). Isolates from asymptomatic shedders were among all three sub-lineages. Whole genome sequencing provided evidence of bacterial genetic similarity, which corroborated 10/12 putative epidemiologic linkages among cases and asymptomatic shedders, as well as 3/3 repeat positives (presumed relapses), with a median of one single nucleotide polymorphism difference. These findings highlight various patterns of typhoid transmission in Samoa that differ between urban and rural regions as well as genomic subtypes. Asymptomatic shedders, detectable only through household investigations, are likely an important reservoir and mobile agent of infection. This study advances a "Samoan S. Typhi framework" that supports current and future typhoid surveillance and control efforts in Samoa.

Humans↗

PubMed2026

Identification of a novel HIV-1 circulating recombinant form (CRF209_cpx) and its descendant unique recombinant form (URF) CRF209_cpx/B among MSM in Guangdong, southern China.

BACKGROUND: The epidemic of human immunodeficiency virus type 1 (HIV-1) continues to pose a significant global health challenge, with increasing genetic diversity. The co-circulation of multiple subtypes among the local population facilitates the emergence of unique or circulating recombinant forms (URFs or CRFs). In China, the predominant strains include CRF07_BC, CRF01_AE, CRF55_01B, and subtype B. This study characterizes a novel CRF209_cpx and its descendant recombinant CRF209_cpx/B among men who have sex with men (MSM) in Guangdong, southern China. METHODS: Individuals infected with URFs with similar genetic characteristics were recruited during routine surveillance of pretreatment drug resistance. Near full-length genomes (NFLGs) were amplified with two overlapping fragments using a serial dilution nested PCR approach after reverse transcription. We used SimPlot and IQ-TREE softwares to conduct recombination analyses and phylogenetic inferences. Time-scaled maximum clade credibility (MCC) phylogenetic trees were reconstructed using BEAST software to estimate evolutionary origins. Genotypic drug resistance mutations were interpreted via the Stanford HIV Database, and coreceptor usage was predicted using geno2pheno coreceptor 2.5 and the HIVcoPRED tool. RESULTS: Four NFLG sequences were obtained and identified as a novel CRF209_cpx, generated by recombination among CRF01_AE, CRF07_BC and subtype B. Phylogenetic analyses revealed that all the parental segments clustered with lineages prevalent among MSM in China. Bayesian evolutionary analysis estimated that the most recent common ancestor (tMRCA) of CRF209_cpx to have evolved between 2011 and 2013. The fifth strain was identified as a URF recombined from nascent CRF209_cpx and B. No transmitted drug resistance mutation was detected in these five sequences. The four CRF209_cpx sequences primarily utilized the CXCR4 coreceptor, while the URF exhibited R5/X4 dual tropism. CONCLUSIONS: The emergence of the complex CRF209_cpx and novel URF of CRF209_cpx/B highlights the active HIV-1 epidemic within the MSM population in Guangdong, underscoring the necessity for enhanced molecular surveillance and precise public health intervention in this key population.

HIV-1↗

PubMed2026

Structural and tissue-specific organisation of endocrine Fgf19 and Fgf21 signalling in rainbow trout.

Endocrine fibroblast growth factors (FGF19 subfamily) play a key role in regulating metabolic homeostasis in vertebrates. However, their functional diversification in salmonids remains poorly understood. In this study, we conducted an integrative characterisation of Fgf19 and Fgf21 signalling in rainbow trout (Oncorhynchus mykiss) by combining phylogenetic, structural and expression analyses. Phylogenetic analyses revealed the conservation of single fgf19 and fgf21 genes, despite the extensive expansion of receptors post-Ss4R (salmonid-specific fourth-round whole genome duplication). Structural modelling and molecular dynamics simulations demonstrated the stable interactions of both ligands to multiple Fgfr isoforms, with receptor-specific energetic profiles and conserved core interaction residues. Tissue expression profiling revealed clear differences from mammalian models, such as predominant hepatic fgf19 expression and the absence of hepatic fgf21 under basal conditions. In addition, there were complex and tissue-dependent distributions of fgfr and klotho transcripts. These findings support a receptor-driven diversification model of endocrine Fgf signalling in salmonids, suggesting enhanced endocrine plasticity associated with the retention of receptors following post-genomic duplication. Taken together, our findings provide new insights into the structural and regulatory organisation of endocrine Fgf signalling, as well as its potential role in metabolic regulation in rainbow trout.

Animals↗

PubMed2025

Phylogenomic Analyses Reveal that Panguiarchaeum Is a Clade of Genome-Reduced Asgard Archaea Within the Njordarchaeia.

The Asgard archaea are a diverse archaeal phylum important for our understanding of cellular evolution because they include the lineage that gave rise to eukaryotes. Recent phylogenomic work has focused on characterizing the diversity of Asgard archaea in an effort to identify the closest extant relatives of eukaryotes. However, resolving archaeal phylogeny is challenging, and the positions of 2 recently described lineages-Njordarchaeales and Panguiarchaeales-are uncertain, in ways that directly bear on hypotheses of early evolution. In initial phylogenetic analyses, these lineages branched either with Asgards or with the distantly related Korarchaeota, and it has been suggested that their genomes may be affected by metagenomic contamination. Resolving this debate is important because these clades include genome-reduced lineages that may help inform our understanding of the evolution of symbiosis within Asgard archaea. Here, we performed phylogenetic analyses revealing that the Njordarchaeales and Panguiarchaeales constitute the new class Njordarchaeia within Asgard archaea. We found no evidence of metagenomic contamination affecting phylogenetic analyses. Njordarchaeia exhibit hallmarks of adaptations to (hyper-)thermophilic lifestyles, including biased sequence compositions that can induce phylogenetic artifacts unless adequately modeled. Panguiarchaeum is metabolically distinct from its relatives, with reduced metabolic potential and various auxotrophies. Phylogenetic reconciliation recovers a complex common ancestor of Asgard archaea that encoded the Wood-Ljungdahl pathway. The subsequent loss of this pathway during the reductive evolution of Panguiarchaeum may have been associated with the switch to a symbiotic lifestyle, potentially based on H2-syntrophy. Thus, Panguiarchaeum may contain the first obligate symbionts within Asgard archaea besides the lineage leading to eukaryotes.

Phylogeny↗

PubMed2026

Genetic heterogeneity and pathogenic potential of historical Crimean-Congo hemorrhagic fever virus isolates in China.

The Crimean-Congo hemorrhagic fever virus (CCHFV) poses a significant public health threat. In China, CCHFV has been circulating for decades, yet the genomic diversity and pathogenic potential of the circulating strains remain poorly characterized, hindering risk assessment and countermeasure development. In this study, we recovered 24 historical CCHFV strains isolated between 1966 and 2004 from humans, ticks and jerboas in Xinjiang Uyghur Autonomous Region of China. Whole-genome sequencing was performed, followed by comprehensive analyses of their phylogenetic relationships, in vitro infectivity and in vivo pathogenicity. Phylogenetic analyses revealed high genetic heterogeneity, identifying seven genotypes for the L segment, nine for the M segment (including a novel Asia 4 genotype), and nine for the S segment. Amino acid mutation analysis revealed that the mucin-like domain (MLD) of the glycoprotein (GP) exhibited the highest mutation rate, contributing substantially to sequence diversity. In vitro, Asia 2 (75024) and Asia 3 (79121M18) strains exhibited robust replication in monkey-, hamster-, and human-derived cell lines. In C57BL/6 mice, all four representative strains induced viral replication and specific antibody responses (IgM and IgG), causing mild to moderate pathological damage in the liver, spleen, and kidneys. In IFNAR-/- mice, virulence varied markedly among representative strains: Asia 2 and Asia 3 strains were highly lethal (LD50 < 1 TCID50), Asia 1 was moderately virulent (LD50 = 142.5 TCID50), and Asia 4 exhibited atypical, non-dose-dependent mortality. Collectively, our work reports a novel Asia 4 genotype and suggests strain- and lineage-associated differences in virulence for CCHFV in China, providing critical insights for surveillance and targeted countermeasure development.

Animals↗

PubMed2026

Population-scale disease-associated tandem repeat analysis reveals locus and ancestry-specific insights.

Tandem repeat (TR) expansions, including short TRs (motifs ≤6 bp) and variable number TRs (motifs >6 bp), underlie many monogenic disorders, with variable length and sequence influencing pathogenicity, penetrance, severity, and onset. Accurate genotype-phenotype correlation and disease prevalence estimation require characterization beyond repeat length. Here we present a population-scale analysis of 66 disease-associated TR loci using long-read assemblies from 2530 diverse haplotypes from 1265 unaffected donors. Integrating repeat length, motif composition, local ancestry, linkage disequilibrium, and phylogenetic analyses, we reveal extensive locus-, population-, and allele-specific variation shaping disease risk. Up to 8.5% of individuals carry expansions above established pathogenic thresholds, many containing interrupting motifs or sequence structures that attenuate pathogenicity. After excluding alleles from loci with uncertain disease association, non-pathogenic interrupted expansions, and carrier states inconsistent with inheritance patterns, ~4% carried expansions predicted to confer disease risk, largely at adult-onset loci with reduced penetrance. Ancestry-resolved analyses uncover population-specific TR architectures contributing to epidemiological disparities in repeat expansion disorders. Phylogenetic analyses identify conserved ancestral alleles and loci with recent instability. We describe variable linkage disequilibrium patterns and recombination signatures around specific disease-associated TR loci. Our findings emphasize integrating sequence, ancestry, and evolutionary context to understand the complex landscape of disease-associated TRs.

Humans↗

PubMed2026

Classification and sequencing of hepatitis D virus from a large cohort of chronically infected individuals paired with co-infecting hepatitis B virus sequencing: a genomic characterisation study.

BACKGROUND: The most severe form of viral hepatitis is caused by co-infection of hepatitis D virus (HDV) and hepatitis B virus (HBV). Phylogenetic analyses classify HBV and HDV into eight major genotypes: HBV GTA to GTH and HDV GT1 to GT8. Paired HBV and HDV sequencing data from participants with chronic hepatitis delta are scarce. We aimed to sequence and genotype HDV and HBV from a large cohort of participants from clinical studies and diverse countries of origin. METHODS: 407 participants with chronic hepatitis D from 24 countries were characterised (124 participants from MYR301 clinical trial, 93 from MYR204, 114 from MYR202, and an additional 76 participants from diverse geographical locations). HBV and HDV from participants were analysed using sequencing, enzyme immunoassay, or both to determine HBV and HDV genotypes. BLAST analysis and phylogenetics were used to determine HBV and HDV genotypes with reference sequence libraries. Bulevirtide treatment response (measured by HDV RNA decline and normalisation of alanine aminotransferase) was compared by genotype for MYR trial participants. FINDINGS: HDV sequencing assays were successful for 386 (95%) of 407 participants and HBV sequencing or serology-based HBV genotyping assays were successful for genotyping 395 (97%) participants. For individual genotypes, HBV GTD (336 [83%] participants) and HDV GT1 (364 [89%]) were the most prevalent. For paired HBV-HDV genotypes, HBV-HDV D/1 was most common (320 [79%] of 407) followed by A/1 (30 [7%]). Phylogenetic analyses of HDV full-genome sequences showed distinct clusters of sequences within HDV GT1, and four novel provisional HDV GT1 subgenotypes, HDV GT1fp to HDVGT1ip, were identified. For 218 MYR clinical trial participants, bulevirtide treatment response was similar across HDV GT1 subgenotypes (both established and newly identified). INTERPRETATION: Novel HDV subgenotypes identified in this study indicate a greater genetic diversity of HDV GT1 than previously recognised. This knowledge will be important for developing better diagnostics, and in understanding HDV genotype-specific biology and response to treatment. More extensive HDV sequencing from under-sampled regions, such as Africa, is needed to determine the true breadth of HDV sequence and genotype diversity. FUNDING: Gilead Sciences.

Hepatitis Delta Virus↗

PubMed2026

A comparative analysis of the clinical and genomic characteristics of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus in Korea and Japan.

Panton-Valentine leukocidin (PVL) is a leukocyte-lytic toxin produced by Staphylococcus aureus, which is primarily associated with skin and soft tissue infections. Notably, there has been an increase in the number of cases caused by the USA300 lineage in Japan. However, the reported prevalence of USA300 is limited in other Asian countries, including Korea. This study investigated the prevalence of PVL-positive methicillin-resistant S. aureus (MRSA) in Korea and Japan and compared their molecular epidemiological characteristics. A total of 463 MRSA strains were analyzed, comprising 283 strains from patients visiting two hospitals in Seongnam and Seoul, Korea, and 180 strains from six hospitals in Tokyo, Japan, between 2018 and 2019. The PVL-encoding genes lukS/F-PV were detected using PCR. Molecular epidemiological and phylogenetic analyses were performed using next-generation sequencing. Overall, 27 (9.5%) PVL-positive MRSA strains were detected among strains isolated from Korea, and 16 (8.9%) were detected among those isolated from Japan. Genotyping of PVL-positive strains revealed that 85.2% of Korean and 81.3% of Japanese strains belonged to USA300. Most USA300 strains from Japan and Korea formed distinct clusters in phylogenetic analyses. Meanwhile, ΨUSA300 and ST22-PT, clones that are prevalent in Japan, were isolated in Korea. This study showed that USA300 strains, which are becoming more prevalent in Japan, are also present in Korea. Furthermore, this study suggests that ΨUSA300 and ST22-PT may be spreading between these two countries. Therefore, it is necessary to continue monitoring the epidemiological trends of PVL-positive MRSA clones both domestically and internationally.IMPORTANCEPanton-Valentine leukocidin (PVL) is a major toxin produced by Staphylococcus aureus. Although a rapid increase in PVL-positive strains has been reported in Japan, data on PVL-positive strains in Korea remain limited. In this study, we performed a comparative analysis of PVL-positive S. aureus isolates from Korea and Japan. The results showed that the clinical backgrounds and genetic profiles of PVL-positive strains isolated in Korea and Japan were highly similar. Furthermore, we confirmed for the first time that clones circulating in Japan, including ΨUSA300 and ST22-PT, were also isolated in Korea. These findings provide valuable insights into the epidemiological status of PVL-positive S. aureus in East Asia.

Leukocidins↗

PubMed2024

Complementing aculiferan mitogenomics: comparative characterization of mitochondrial genomes of Solenogastres (Mollusca, Aplacophora).

BACKGROUND: With the advances in high-throughput sequencing and bioinformatic pipelines, mitochondrial genomes have become increasingly popular for phylogenetic analyses across different clades of invertebrates. Despite the vast rise in available mitogenomic datasets of molluscs, one class of aplacophoran molluscs - Solenogastres (or Neomeniomorpha) - is still neglected. RESULTS: Here, we present six new mitochondrial genomes from five families of Solenogastres (Amphimeniidae, Gymnomeniidae, Proneomeniidae, Pruvotinidae, Simrothiellidae), including the first complete mitogenomes, thereby now representing three of the four traditional orders. Solenogaster mitogenomes are variable in size (ranging from approximately 15,000 bp to over 17,000 bp). The gene order of the 13 protein coding genes and two rRNA genes is conserved in three blocks, but considerable variation occurs in the order of the 22 tRNA genes. Based on phylogenetic analyses and reconstruction of ancestral mitochondrial genomes of Aculifera, the position of (1) trnD gene between atp8 and atp6, (2) trnT and P genes between atp6 and nad5, and (3) trnL1 gene between G and E, resulting in a 'MCYWQGL1E'-block of tRNA genes, are all three considered synapomorphies for Solenogastres. The tRNA gene block 'KARNI' present in Polyplacophora and several conchiferan taxa is dissolved in Solenogastres. CONCLUSION: Our study shows that mitogenomes are suitable to resolve the phylogenetic relationships among Aculifera and within Solenogastres, thus presenting a cost and time efficient compromise to approach evolutionary history in these clades.

Genome, Mitochondrial↗

PubMed2025

Transmission of extended spectrum β-lactamase-producing Escherichia coli and antimicrobial resistance gene flow across One Health compartments in eastern Africa: a whole-genome sequence analysis from a prospective cohort study.

BACKGROUND: The One Health paradigm considers interdependence of human, animal, and environmental health. However, there is little evidence from high-income countries to support the importance of a One Health approach to addressing spread of antimicrobial resistance (AMR). Given AMR is a global threat, understanding how the close interactions of humans with animals and the environment in low-income settings affect the spread of AMR is important. We aimed to investigate diversity and transmission of extended spectrum β-lactamase (ESBL)-producing Escherichia coli across household-linked One Health compartments using genomic data. METHODS: We sequenced whole genomes of ESBL-producing E coli isolates from humans, animals, and the environment from a prospective, longitudinal cohort study conducted in Malawi (April 29, 2019, to Dec 3, 2020) and Uganda (July 16, 2020, to Aug 6, 2021). In the cohort study, 259 households were enrolled at baseline in Malawi and 92 in Uganda from a mix of urban, peri-urban, and rural areas. Households were followed up at months 1, 3, and 6 in Malawi and at months 1, 2, and 4 in Uganda. Samples collected at each visit included human and animal stool, environmental samples from hand-contact areas, food, and water, and broader environmental samples such as river water. Samples were cultured in buffered peptone water and then ESBL chromogenic agar to isolate ESBL-producing E coli. ESBL-producing E coli isolates underwent whole-genome sequencing. We performed phylogenetic analyses, and in-silico multi-locus sequence typing, characterised AMR determinants and linked genotypes with sample location, ecological source, and other covariates. We performed fine-scale single nucleotide polymorphism (SNP) and network analysis to infer strain and plasmid transmission across ecological compartments. The primary outcome was colonisation with ESBL-producing E coli. Secondary outcomes were genomic clusters and ESBL genomic determinants within and between One Health compartments. FINDINGS: We found high diversity of ESBL-producing E coli, with 170 sequence types and 166 genomic clusters identified from 2344 genomes, including 1814 genomes from Malawi (907 human, 221 animal, and 686 environmental) and 530 genomes from Uganda (380 human, 147 animal, and three environmental). Sequence type (ST)131 dominated in Malawi (209 [11·5%] of 1814 genomes), and ST10 dominated in Uganda (45 [8·5%] of 530 genomes). Common ESBL genes blaCTX-M-15 (1604 [68·4%] of 2344 genomes) and blaCTX-M-27 (336 [14·3%] of 2344 genomes) were carried on a complex network of 55 and 30 different plasmids. This diversity of plasmids presented multiple pathways for dissemination and revealed high force of selection. Phylogenetic analyses revealed common intermixing of isolates between humans, animals, and the environment. SNP transmission analysis revealed ecologically overlapping clusters, suggesting ESBL-producing E coli co-circulation both within and between compartments with frequent spillover events. Applying a five-SNP threshold, we inferred 463 human-environment transmission events, 146 human-animal events, and 142 animal-environment events. INTERPRETATION: Our work suggests that a One Health approach is crucial to addressing AMR in eastern Africa. Improving water, sanitation, and hygiene systems will create a safer environment, reduce spillovers of AMR bacteria between compartments, and eventually reduce AMR reservoirs in the environment and in animals. FUNDING: Medical Research Council, National Institute for Health and Care Research, and Wellcome Trust.

Humans↗

PubMed2024

A series of patients infected with the emerging tick-borne Yezo virus in China: an active surveillance and genomic analysis.

BACKGROUND: Yezo virus (YEZV) is an emerging tick-borne pathogen, which was initially reported in Japan in 2021. Only one patient had been reported in China so far. We aimed to describe the epidemiological, clinical, and laboratory findings of a series of patients, and to characterise the viral genomes of YEZV. METHODS: In this active surveillance and genomic analysis, we conducted active surveillance at Mudanjiang Forestry Central Hospital, Heilongjiang Province of northeast China. Participants were eligible for inclusion if they sought medical care for a recent tick bite between May 1 and July 31, in 2022 and 2023, and between May 1 and July 10, in 2024. We collected sera from participants to detect YEZV infection by meta-transcriptomic sequencing, real-time RT-PCR, and indirect immunofluorescence assay. We isolated YEZV by cell culture and characterised the pathogen by morphological and phylogenetic analyses. FINDINGS: A series of 18 patients with YEZV infection (12 male and six female; median age 53 years, IQR 45-60) were identified among 988 participants. The patients presented with fever (18 patients, 100%), headache (ten patients, 56%), dizziness (nine patients, 50%), malaise (three patients, 17%), lumbago (three patients, 17%), and cough (three patients, 17%). Nine (50%) patients had rash around the tick bite site and four (22%) had lymphadenopathy. Nine (50%) patients had gastrointestinal symptoms, and five (28%) had neurological symptoms. We observed leukopenia in ten (63%) and thrombocytopenia in five (31%) of 16 assessed patients. Elevated hepatic transaminase concentrations were identified in 13 (72%) of all 18 patients, lactate dehydrogenase or α-hydroxybutyric dehydrogenase in nine (50%), serum amyloid protein A in 13 (72%), and hypersensitive C-reactive protein in ten (56%). Eight (7%) of 119 Ixodes persulcatus ticks removed from participants were positive for YEZV. Three YEZV strains were isolated from the sera of patients. Ten viral genomes were obtained from five patients, a blood-sucking I persulcatus removed from a participant, and four host-questing tick samples collected in the areas where patients were identified or in the adjacent region. Phylogenetic analyses revealed that YEZVs in either patients or ticks were divided into two clades, each with distinct mutations. INTERPRETATION: Awareness of YEZV infection is important and clinicians should consider the virus when diagnosing patients with suitable symptoms. FUNDING: National Key Research and Development Program of China. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Humans↗

PubMed2026

Characterization and comparative analysis of the complete chloroplast genomes of twelve Allium species from Kazakhstan.

The genus Allium L. represents one of the largest and taxonomically complex groups of monocots, with Central Asia recognized as a major center of its diversity. Despite the high species richness of Allium in Kazakhstan, genomic data for many native taxa remain limited. In this study, we sequenced, assembled, and analyzed the complete chloroplast genomes of 12 Allium species from Kazakhstan. All chloroplast genomes exhibited a conserved quadripartite structure, with genome sizes ranging from 152,029 to 153,521 bp and a uniform gene content of 137 genes, including 88 protein-coding genes, 38 tRNAs, 8 rRNAs, and 3 pseudogenes. Comparative analyses revealed high structural conservation, with most sequence divergence concentrated in intergenic regions. Several highly variable regions, including ycf1, matK, rpoC2, and ycf2, were identified as potential molecular markers. Phylogenetic analyses based on chloroplast genome sequences using Maximum Likelihood and Bayesian approaches recovered three major chloroplast genome-based lineages within Allium, largely consistent with previous phylogenomic studies. Divergence-time analyses suggested that major chloroplast lineage diversification events within the genus occurred during the early Eocene (ca. 47.97 Mya). Overall, this study expands the currently available chloroplast genomic resources for Allium from Kazakhstan, provides insights into chloroplast genome evolution and chloroplast genome-based relationships, and establishes a valuable foundation for future phylogenetic, taxonomic, and evolutionary studies of this diverse genus.

Genome, Chloroplast↗

PubMed2026

The novel transcriptional activator Bhr1 combining NTPase and Zn(II)2Cys6 DNA-binding domains controls (hemi-)cellulase response to mannose-rich substrates in the white-rot fungus Dichomitus squalens.

The regulatory landscape responsible for lignocellulose degradation in white-rot basidiomycete fungi remains largely unexplored. In this study, we characterize a novel transcriptional activator, Bhr1, in the white-rot fungus Dichomitus squalens. Bhr1 exhibits an unusual domain architecture that combines a septin-like P-loop NTPase fold with Zn(II)2Cys6 DNA-binding domains and plays a critical role in activating (hemi-)cellulase enzyme production when D. squalens is exposed to mannose-rich substrates. Using CRISPR/Cas9-mediated gene editing, we generated a bhr1 disruption mutant that displayed distinct phenotypes and enzyme activity profiles on mannose and guar gum compared to the wild type. RNA sequencing data indicate that Bhr1 induces specific (hemi-)cellulase-encoding genes without altering the expression of genes encoding sugar transporters or sugar metabolic enzymes. Phylogenetic analyses show that Bhr1 is basidiomycete specific and largely restricted to saprotrophic and plant-associated Agaricomycetes fungi. Based on the domain architecture of Bhr1 and the effects of its disruption in D. squalens, our findings reveal a lineage-specific regulatory innovation in basidiomycetes that is distinct from those described in ascomycetes. Elucidating the function and evolutionary conservation of Bhr1 advances our understanding of lignocellulose degradation at the molecular level in basidiomycete fungi and may inform studies of their ecological adaptation and the development of biotechnological applications.IMPORTANCEUnderstanding the transcriptional regulatory mechanisms in white-rot fungi, such as Dichomitus squalens, is crucial for advancing our knowledge of lignocellulose degradation. This study identifies D. squalens Bhr1 as a key regulator of (hemi-)cellulase production on mannose-rich substrates and further distinguishes basidiomycete transcription factors involved in plant biomass degradation from their ascomycete counterparts. Our findings highlight the significance of lineage-specific regulators in facilitating adaptive enzyme production for efficient biomass utilization, which is critical to carbon cycling in terrestrial ecosystems. This work establishes a foundation for exploring novel regulatory strategies among wood-degrading fungi, potentially enabling targeted strain engineering in biotechnological applications.

Mannose↗

PubMed2026

Phototrophicity and genomic composition in plant-associated Sphingomonas faeni strains.

Solar radiation impacts most life forms on Earth as an energy source or a regulatory signal. Still, relatively little is known about phototrophic potential and strategies of environmental bacteria beyond cyanobacteria. This study explores the phototrophy related genomic diversity of Sphingomonas faeni strains from boreal, sub-arctic and arctic regions. We analyzed the genomes of 25 plant-associated S. faeni strains isolated from Vaccinium myrtillus, Oxyria digyna, V. vitis-idaea, and Bistorta vivipara, along with a reference S. faeni genome MA-Olki. The strains showed diversity both in overall genome level but also in phototrophic capabilities: Seven strains were identified as aerobic anoxygenic phototrophic bacteria with a complete photosynthesis gene cluster, 16 strains contained xanthorhodopsin genes, and three strains were non-phototrophic, possessing no aerobic anoxygenic phototrophic or xanthorhodopsin genes. Aerobic anoxygenic phototrophic strains were found exclusively in Vaccinium hosts. O. digyna contained only xanthorhodopsin containing strains and B. vivipara showed xanthorhodopsin genes and one non-phototrophic strain. V. vitis-idaea hosted strains for all three different phototrophy categories. Phylogenetic analyses showed aerobic anoxygenic phototrophic positive strains forming a tight phylogenetic group. Xanthorhodopsin strains and non-phototrophic strains clustered into three different subgroups. Phototrophic strains had more photoreceptors. Aerobic anoxygenic phototrophic strains encoded two 5-aminolevulinic acid synthase isoenzymes, one from a hemT-like gene within the photosynthesis gene cluster and one from a hemA-like gene elsewhere in the genome. Our genomic analysis reveals substantial diversity in phototrophic potential among strains of a single bacterial species isolated from different host plants, possibly reflecting the distinct environmental cues each strain encountered.

aerobic anoxygenic phototrophy↗

PubMed2026

Emergence and phylogeography of the dengue vector Aedes aegypti in Southeastern Iran.

BACKGROUND: Aedes (Stegomyia) aegypti (Linnaeus) is the primary vector of dengue, chikungunya, Zika, and yellow fever viruses. Its recent detection in southeastern Iran raises public health concerns about arbovirus spread to new regions. This study provides the first genetic and phylogeographic analysis of Ae. aegypti populations from Sistan and Baluchistan Province (SBP), Iran, to infer their origin and invasion pathways. METHODS: Mitochondrial COI and ND4 genes were analysed in newly collected Ae. aegypti specimens from border areas, ports, and urban centres of SBP. Haplotype network analyses were constructed using the TCS method in PopART, and phylogenetic analyses were conducted using global reference sequences. RESULTS: Iranian specimens comprised 7 COI haplotypes (n = 18) and 10 ND4 haplotypes (n = 17). COI phylogeny placed Iranian specimens into two main clades, while ND4 analysis distributed them across several derived clades, mostly clustering with lineages from Latin America (Brazil, Mexico) or Africa. One Iranian specimen showed a close relationship with a Saudi Arabian sequence (bootstrap: 98%) near the basal region. Combined COI + ND4 analysis revealed a monophyletic clade of Iranian specimens with a Sri Lankan specimen, distinct from other global lineages. The global COI network (n = 47) showed a star-like topology with a dominant haplotype 1 shared among 10 Iranian specimens. The ND4 network (n = 31) revealed a complex topology with 18 haplotypes, where a Saudi Arabian and one Iranian specimen (~30 mutational steps) possibly represented the peripheral root. CONCLUSIONS: Detection of diverse Ae. aegypti clades confirm establishment of this vector in southeastern Iran. Results support multiple introductions and genetic connectivity with Latin America, Africa, and South Asia, pointing to an emerging invasion corridor. Continued genomic surveillance and integrated vector monitoring are urgently needed to guide prevention strategies.

Animals↗

PubMed2026

Phylogeography and molecular evolution of Newcastle disease virus across a century of global surveillance.

Newcastle disease virus (NDV) remains one of the most economically important avian pathogens worldwide, causing recurrent outbreaks in poultry despite decades of vaccination and disease control efforts. Since the first reported outbreak of NDV a hundred years ago, numerous molecular epidemiological studies have been conducted globally across diverse geographic and production settings. Following a century of NDV circulation and evolution, the present study aimed to compile all publicly available NDV sequence data and perform a comprehensive global analysis of the genetic diversity, phylogenetic relationship, and global spatiotemporal distribution of NDV over a 100-year timescale. All publicly available NDV complete genome and full-length fusion (F) gene sequences were retrieved from GenBank up to February 2026. Following rigorous quality control, phylogenetic analyses were performed based on complete genomes and F gene datasets. Phylogenetic analysis identified two genotypes within Class I and 20 genotypes within Class II NDVs, with extensive diversification at the sub-genotype level. Genotype XIII exhibited the greatest sub-genotypic diversity, while genotype VII represented the most globally disseminated genotype, reported across 36 countries. Chronological assessment based on the earliest available reports indicated an increasing number of recognized genotypes from the 1930s to recently described sub-genotypes such as XIII.2.3 and XXII.2.2. Regional diversity analysis revealed the highest genotype diversity in Western Africa, Eastern Asia, and Southern Asia. Comparative residue analysis demonstrated substantial genotype-specific variation within critical functional domains of the fusion protein, including cleavage sites, neutralizing epitopes, and heptad repeat regions. Overall, this study provides the first comprehensive 100-year global overview of NDV evolution and phylogeography. The findings highlight continuous viral diversification, broad geographic dissemination of multiple genotypes, and ongoing molecular variation, emphasizing the need for sustained genomic surveillance and periodic evaluation of vaccine compatibility with emerging NDV genotypes.

100-years of data↗

PubMed2026

Halolitoreus marinus gen. nov., sp. nov. and Halolitoreus rarus sp. nov., halophilic archaea isolated from diverse coastal tidal flats, and proposal of the novel family Halolitoreaceae fam. nov. in the order Halobacteriales within the class Halobacteria.

Coastal tidal flats represent dynamic saline environments that harbor largely unexplored haloarchaeal communities. In this study, amplicon sequencing, metagenomic analyses, and cultivation-based approaches revealed substantial haloarchaeal diversity in tidal flats from four provinces of eastern China despite their relatively low salinity. Five haloarchaeal strains, designated YSMS36T, DYSN1, QDMS2, CMSO5T, and ZSTT2, were isolated from diverse tidal flats. Theses strains shared 16S rRNA gene sequence similarities of 92.1-92.2% with their closest validly named relative, Salinilacihabitans rarus AD-4T. Phylogenetic analyses based on 16S rRNA and rpoB' gene sequences showed that the five strains formed a distinct and well-supported monophyletic lineage, separated from currently recognized members of the class Halobacteria. Average amino acid identity (AAI), average nucleotide identity (ANI), and digital DNA-DNA hybridization (dDDH) values between these five strains and the related Halobacteria representatives were 49.3-62.7%, 66.9-74.9%, and 16.2-29.5%, respectively, and well below the accepted thresholds for species and genus delineation. Phylogenomic analyses further supported their placement within a novel family of the order Halobacteriales. Based on phylogenetic, genomic, chemotaxonomic, and phenotypic analyses, these five strains represent two novel species of a novel genus within a novel family. The names, Halolitoreaceae fam. nov., Halolitoreus marinus gen. nov., sp. nov., and Halolitoreus rarus sp. nov. are herein proposed.

Coastal tidal flat↗

PubMed2025

Whole genome sequencing and phylogenetic classification accelerate the implementation of respiratory syncytial virus genomic surveillance in Canada: a pilot study.

UNLABELLED: Whole genome sequencing (WGS) has emerged as a powerful tool to facilitate the study of existing and emerging infectious diseases. WGS-based genomic surveillance provides information on the genetic diversity and tracks the evolution of important viral pathogens, including respiratory syncytial virus (RSV). Multiplex tiling polymerase chain reaction (PCR) assays have been used to facilitate sequencing of a variety of pathogens in support of genomics-based surveillance initiatives. We developed, optimized, and implemented multiplex tiling PCR assays for RSVA and RSVB capable of generating near-complete genomes in the majority of contemporaneous specimens tested. A pilot data set comprising 52 RSVA and 37 RSVB genomes derived from Canadian clinical specimens during the 2022-2023 respiratory virus season was used to perform phylogenetic analyses using both near-complete genome and glycoprotein (G) sequences. Overall, the RSV phylogenetic tree built with whole genomes showed identical lineage clusters as compared to the G gene but was more discriminatory. Moreover, the availability of complete genomes enables the identification of a broader range of mutations. For instance, mutations identified in the fusion protein among Canadian isolates tested here, including S377N, K272M, S276N, S211N, S206I, and S209Q, could affect the efficacy of current vaccines or antiviral-based therapeutics. In conclusion, our work reinforces other recent studies demonstrating the utility of multiplex tiling PCR assays to facilitate high-throughput WGS of RSV, which is capable of supporting enhanced genomic surveillance initiatives, as well as the more comprehensive genomic analyses required to inform public health strategies for the development and usage of vaccines and antiviral drugs. IMPORTANCE: We present assays to efficiently sequence genomes of RSVA and RSVB. This enables researchers and public health agencies to acquire high-quality genomic data using rapid and cost-effective approaches. Genomic data-based comparative analysis can be used to conduct surveillance and monitor circulating isolates for efficacy of vaccines and antiviral therapeutics.

Humans↗