Phylogenetic Research Research Articles

Detection and Phylogenetic Analysis of an Exotic Strain of Porcine Epidemic Diarrhea Virus and Its Effect on an Affected Herd Immunized Against the Endemic Strain in Thailand

Porcine epidemic diarrhea (PED) is caused by the PED virus, with genogroup 2 (G2), comprising G2a and G2b, being the primary contributors to outbreaks worldwide. In Thailand, G2a was the only virulent strain identified until the emergence of the first G2b strain in 2014, followed by additional G2b strains in 2015–2016, particularly those closely related to virulent strains from China. This led to increased awareness of more frequent and complex outbreaks. This study examined farms affected by G2a and G2b strains, both employing planned exposure of sows to intestines from G2a-affected piglets, a traditional practice in Thailand. The analysis focused on the milk and colostrum profiles of sows, including viral neutralization and ELISA methods, as well as histopathological assessments of piglet intestinal villi. Additionally, a novel G2b strain was sequenced for phylogenetic and protein structure analyses. The results revealed no significant differences in colostrum and milk profiles between the farms. However, piglets infected with G2b showed significantly more severe intestinal damage. A unique insertion in the protein structure of the novel G2b strain led to the identification of a new epitope and potential changes in viral properties. This study highlights the importance of monitoring emerging strains and provides valuable insights for enhancing preventive strategies and advancing phylogenetic research.

The Organellar Genomes of Melanthalia abscissa and Polyopes polyideoides (Rhodophyta, Florideophyceae).

Florideophyceae is the most species rich red algal class, including large numbers of well-studied, economically important species and lesser-known clades. We present the complete plastid and mitocondrial genome assemblies of two Florideophycean species, Melanthalia abscissa (Gracilariaceae) and Polyopes polyideoides (Halymeniaceae). We identified more large-scale rearrangements within the plastid genomes of Gracilariales than within Halymeniales. Maximum likelihood phylogenies using rbcL data support the placement of both M. abscissa and P. polyideoides samples in monophyletic genera. However, not all genera within Halymeniales were recovered as monophyletic. Sequences that appear to be derived from red algal plasmids were identified within the plastid genome of M. abscissa. Determining the presence or absence of plasmid-derived sequences in the P. polyideoides plastome is more difficult due to a lack of publicly available data for Halymeniaceae. The addition of the sequences produced by this study will support further phylogenetic and systematic research on these Rhodophytan genera and orders.

The complete chloroplast genome of Vaccinium henryi Hemsl. 1889 (Ericaceae)

Vaccinium henryi Hemsl. 1889 is an endemic deciduous shrub in China, belonging to the family Ericaceae. In this study, the first complete chloroplast genome of V. henryi was assembled and annotated. The genome was 176,339 bp in size containing a large single-copy region of length 106,115 bp, a small single-copy region of length 3022 bp, and a pair of inverted repeat regions of 33,601 bp each. It contained 139 genes, including 91 protein-coding genes, 40 tRNA genes, and 8 rRNA genes. Phylogenetic analysis exhibited that V. henryi and V. oldhamii were phylogenetic closely related. The chloroplast genome of V. henryi would provide valuable information for phylogenetic and evolutionary research on genus Vaccinium.

Characterization of the Complete Chloroplast Genomes and Phylogenetic Analysis of Sapotaceae

The Sapotaceae family comprises 65–70 genera and over 1250 species, holding significant ecological and economic value. Although previous studies have made some progress in the phylogenetic relationships and classification of Sapotaceae, many issues remain unresolved and require further in-depth research. In this study, we sequenced and assembled the complete chloroplast genomes of 21 plants from 11 genera of Sapotaceae, conducted a comparative genomic analysis, and performed a phylogenetic analysis by incorporating 16 previously published chloroplast genomes of Sapotaceae. The results showed that the chloroplast genome sizes in 21 plants of Sapotaceae range between 157,920 bp and 160,130 bp, exhibiting the typical quadripartite structure. Each genome contains 84–85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes, while the ndhF gene is absent in Pouteria campechiana and Pouteria sapota. The relative synonymous codon usage (RSCU) analysis showed that isoleucine (Ile) is the most commonly used, while the codon for methionine (Met) is the least utilized. Additionally, five highly variable regions (petA-psbJ, psbI-trnS-GGA, rpl2_2-psbA, rps19-rpl2_2, and ycf4-cemA) and two coding sequences, ycf1 and matK, were identified as candidate molecular markers for species differentiation and a phylogenetic analysis within the Sapotaceae family. Phylogenetic trees were reconstructed using complete chloroplast genome sequences and analyzed using ML and BI methods, which revealed that the Sapotaceae family is divided into three distinct clades, each receiving strong statistical support (BS = 100, PP = 1). The intergeneric analysis revealed that Madhuca and Palaquium are sister groups (BS = 91, PP = 1), as are Gambeya and Chrysophyllum (BS = 91, PP = 1). Pouteria and Chrysophyllum are among the larger groups in the Sapotaceae family but the traditional classification boundaries of these genera are unstable and unfeasible, as the current genus boundaries fail to support their natural evolutionary relationships. In the phylogenetic tree, Eberhardtia aurata is placed on a separate branch. The morphological classification system shows that E. aurata has rust-colored pubescence on its branches, abaxial leaf surfaces, petioles, and other areas, which clearly distinguishes it from other genera. This study provides valuable insights into advancing phylogenetic research, population genetics, molecular breeding, and conservation strategies by comparing chloroplast genome structures and characteristics and constructing phylogenetic trees.

Comparative analysis of Hymenasplenium (Aspleniaceae) chloroplast genomes from China.

Hymenasplenium is one of the two genera in the large fern family Aspleniaceae. A previous study explored the molecular phylogeny of this genus using several chloroplast DNA fragments and identified three major clades, one of which is the monophyletic Old World clade with southwestern China as its diversity center. To date, there were only a few studies conducted on chloroplast genomes in Hymenasplenium or Aspleniaceae, limiting the understanding of the plastome features and its role in evolution of this group. Here, we studied the complete chloroplast genomes of 12 Hymenasplenium species covering all four subclades of the Old World clade distributed in China. The length of the Hymenasplenium plastomes ranged from 151,617 to 151,930 bp, and contained 129 genes in total, comprising 87 protein-coding, 34 tRNA, and eight rRNA genes. The GC content ranged from 41.8% to 42.1%. Comparative analyses of the Hymenasplenium chloroplast genomes displayed conserved genomic structure and identical gene arrangement. A total of 1,375 simple sequence repeats and 1,639 large repeats were detected. In addition, we detailed hypervariable regions that can be helpful for further phylogenetic research and species delimitation in Hymenasplenium. Furthermore, we supported phylogenetic relationships among major groups as well as possible cryptic speciation found in previous research in the genus. Our study provides new insights into evolutionary history and basic resources for phylogenetic and taxonomic studies of the genus Hymenasplenium.

Cladopusyangjiangensis (Podostemaceae), a new species from Guangdong, South China, redefining the phylogenetic relationships within Cladopus.

This paper introduces Cladopusyangjiangensis, a newly identified species that enriches our understanding of the diversity of the Podostemaceae in East Asia. Distinctive in its morphological traits, this species is characterized by the region's longest flowering shoots and exhibits a high number of elongated leaves per cluster, along with relatively slender roots. Phylogenetic analyses using Maximum Likelihood and Bayesian Inference methods on plastome and matK sequences confirm C.yangjiangensis as a distinct species. It forms a clade with C.fukienensis, its closest relative, together branching off from C.austrosinensis. The plastome of C.yangjiangensis is 132,818 bp in length, comprising two inverted repeat regions of 20,881 bp, which are separated by large and small single-copy regions of 78,713 and 12,343 bp, respectively. Genetic analysis reveals the extensive loss of the ycf1 and ycf2 genes in the chloroplast genome, a trait common to the Podostemaceae, suggesting adaptations to environmental conditions or gene transfers to nuclear or mitochondrial genomes. This study improves the clarity of phylogenetic relationships in previous studies and underscores the importance of continued taxonomic and phylogenetic research.

A DNA barcode reference of Asian ferns with expert-identified voucher specimens and DNA samples

Ferns belong to species-rich group of land plants, encompassing more than 11,000 extant species, and are crucial for reflecting terrestrial ecosystem changes. However, our understanding of their biodiversity hotspots, particularly in Southeast Asia, remains limited due to scarce genetic data. Despite harboring around one-third of the world’s fern species, less than 6% of Southeast Asian ferns have been DNA-sequenced. In this study, we addressed this gap by sequencing 1,496 voucher-referenced and expert-identified fern samples from (sub)tropical Asia, spanning Malaysia, the Philippines, Taiwan, and Vietnam, to retrieve their rbcL and trnL-F sequences. This DNA barcode collection of Asian ferns encompasses 956 species across 152 genera and 34 families, filling major gaps in fern biodiversity understanding and advancing research in systematics, phylogenetics, ecology and conservation. This dataset significantly expands the Fern Tree of Life to over 6,000 species, serving as a pivotal and global reference for worldwide barcoding identification of ferns.

Vindicating Lineage Eliminativism

AbstractThis article defends a selective eliminativist position with respect to the concept of “biological lineage” as used in certain areas of contemporary evolutionary biology. We argue that its primary epistemic roles in these contexts—explaining social evolution and cumulative selection—clash with empirical evidence, and that enforcing the concept of “lineage” even obstructs fruitful research avenues in several biological research fields, including phylogenetic research. Drawing on this, we suggest that, in many instances, it would be best to get rid of the concept of “lineage” and think in terms that are more closely aligned with the empirical complexity of the biological world. Specifically, this entails that, instead of looking for the lineage that may have given rise to the entities possessing certain biological characteristics, biologists should generally look for any potential process allowing such possession, with the formation of a lineage just one possibility among many.

PhyloForge: Unifying Micro- and Macroevolution With Comprehensive Genomic Signals.

The dimensions of phylogenetic research have expanded to encompass the study of large-scale populations at the microevolutionary level and comparisons between different species or taxonomic units at the macroevolutionary level. Traditional phylogenetic tools often struggle to handle the diverse and complex data required for these different evolutionary scales. In response to this challenge, we introduce PhyloForge, a robust tool designed to seamlessly integrate the demands of both micro- and macroevolution, comprehensively utilising diverse phylogenomic signals, such as genes, SNPs, and structural variations, as well as mitochondrial and chloroplast genomes. PhyloForge's innovation lies in its capability to seamlessly integrate multiple phylogenomic signals, enabling the unified analysis of multidimensional genomic data. This unique feature empowers researchers to gain a more comprehensive understanding of diverse aspects of biological evolution. PhyloForge not only provides highly customisable analysis tools for experienced researchers but also features an intuitively designed interface, facilitating effortless phylogenetic analysis for beginners. Extensive testing across various domains, including animals, plants and fungi, attests to its broad applicability in the field of phylogenetics. In summary, PhyloForge has significant potential in the era of large-scale genomics, offering a new perspective and toolset for a deeper understanding of the evolution of life. PhyloForge codes could be found in GitHub (https://github.com/wangyayaya/PhyloForge/), and the program could be installed in Conda (https://anaconda.org/wangxiaobei/phyloforge).

Complete Chloroplast Genomes and Phylogenetic Analysis of Woody Climbing Genus Phanera (Leguminosae).

Phanera Lour., a genus in the subfamily Cercidoideae of the family Leguminosae, is characterized by woody liana habit, tendrils, and distinctive bilobate or bifoliolate leaves. The genus holds important medicinal value and constitutes a complex group characterized by morphological diversity and unstable taxonomic boundaries. However, limited information on the chloroplast genomes of this genus currently available constrains our understanding of its species diversity. Hence, it is necessary to obtain more chloroplast genome information to uncover the genetic characteristics of this genus. We collected and assembled the complete chloroplast genomes of nine representative Phanera plants, including Phanera erythropoda, Phanera vahlii, Phanera aureifolia, Phanera bidentata, Phanera japonica, Phanera saigonensis, Phanera championii, Phanera yunnanensis, and Phanera apertilobata. We then conducted a comparative analysis of these genomes and constructed phylogenetic trees. These species are each characterized by a typical quadripartite structure. A total of 130-135 genes were annotated, and the GC content ranged from 39.25-42.58%. Codon usage analysis indicated that codons encoding alanine were dominant. We found 82-126 simple sequence repeats, along with 5448 dispersed repeats, mostly in the form of forward repeats. Phylogenetic analysis revealed that 16 Phanera species form a well-supported monophyletic group, suggesting a possible monophyletic genus. Furthermore, 10 hypervariable regions were detected for identification and evolutionary studies. We focused on comparing chloroplast genome characteristics among nine Phanera species and conducted phylogenetic analyses, laying the foundation for further phylogenetic research and species identification of Phanera.

Whole genome sequence of the denitrifying thermophile Geobacillus thermodenitrificans subsp. calidus DSM 22629T.

We present a full genome sequence for the thermophilic denitrifier Geobacillus thermodenitrificans subsp. calidus DSM 22629T (3,408,575 bp, 48.94% GC). This genome includes 3,615 predicted genes, including those needed to reduce nitrate to nitrogen gas. This organism and genome sequence provide valuable resources for future phylogenetic, genomic, and biotechnological research.

Seeking the first phylogenetic method–Edvard A. Vainio (1853–1929) and his troubled endeavour towards a natural lichen classification in the late nineteenth century Finland

Edvard August Vainio was a world-renowned Finnish lichenologist. In Finland, however, he was a controversial person due to his strong pro-Finnish political views. Equally disputed was his opinion that systematics should be based on evolutionary theory and phylogenetic thinking. Vainio was familiar with the ideas of the early German phylogeneticists—especially those of Carl Wilhelm von Nägeli – and, applying them, aimed to create an exact method for building a natural classification of lichens already at the end of the nineteenth century. In this respect, Vainio was a true pioneer, as no actual phylogenetic method had yet been developed. In the general spirit of the time, Vainio focused on finding the ancestors of species and other taxa by comparing primitive and derived features of homologous characters. However, Vainio already understood the concept of sister groups in 1880, the identification of which is the basis of all modern phylogenetic research. Nevertheless, the distinctive method developed by Vainio was not so much focused on the construction of a phylogenetic tree, but on revealing the origin of species through the differentiation and fixation of their polymorphic variation. Indeed, Vainio’s species concept is surprisingly similar to the phylogenetic species concepts presented a hundred years later. Although in many ways progressive, Vainio’s views did not influence the development of phylogenetics more widely, but his discussions are nevertheless a valuable source to understanding the early development of phylogenetic theory.

Mitochondrial Genome Assembly and Structural Characteristics Analysis of Gentiana rigescens.

Gentiana rigescens, an alpine plant with significant medicinal value, possesses a complex genetic background. However, comprehensive genomic research on G. rigescens is still lacking, particularly concerning its organelle genome. In this study, G. rigescens was studied to sequence the mitochondrial genome (mitogenome) and ascertain the assembly, informational content, and developmental expression of the mitogenome. The mitogenome of G. rigescens was 393,595 bp in length and comprised four circular chromosomes ranging in size from 6646 bp to 362,358 bp. The GC content was 43.73%. The mitogenome featured 30 distinct protein-coding genes, 26 tRNA genes, and 3 rRNA genes. The mitogenome of G. rigescens also revealed 70 SSRs, which were mostly tetra-nucleotides. In addition, 48 homologous fragments were found between the mitogenome and the chloroplast genome, with the longest measuring 23,330 bp. The documentation of the mitochondrial genome of G. rigescens is instrumental in advancing the understanding of its physiological development. Decoding the G. rigescens mitogenome will offer valuable genetic material for phylogenetic research on Gentianaceae and enhance the use of species germplasm resources.

On the importance of assessing topological convergence in Bayesian phylogenetic inference.

Modern phylogenetics research is often performed within a Bayesian framework, using sampling algorithms such as Markov chain Monte Carlo (MCMC) to approximate the posterior distribution. These algorithms require careful evaluation of the quality of the generated samples. Within the field of phylogenetics, one frequently adopted diagnostic approach is to evaluate the effective sample size and to investigate trace graphs of the sampled parameters. A major limitation of these approaches is that they are developed for continuous parameters and therefore incompatible with a crucial parameter in these inferences: the tree topology. Several recent advancements have aimed at extending these diagnostics to topological space. In this reflection paper, we present two case studies-one on Ebola virus and one on HIV-illustrating how these topological diagnostics can contain information not found in standard diagnostics, and how decisions regarding which of these diagnostics to compute can impact inferences regarding MCMC convergence and mixing. Our results show the importance of running multiple replicate analyses and of carefully assessing topological convergence using the output of these replicate analyses. To this end, we illustrate different ways of assessing and visualizing the topological convergence of these replicates. Given the major importance of detecting convergence and mixing issues in Bayesian phylogenetic analyses, the lack of a unified approach to this problem warrants further action, especially now that additional tools are becoming available to researchers.

Assembly and comparative analysis of the first complete mitochondrial genome of Salix psammophila, a good windbreak and sand fixation shrub.

Salix psammophila, commonly known as the sandlive willow, is a vital shrub species within the Salicaceae family, particularly significant for its ecological role in regions susceptible to desertification and sandy soils. In this study, we assembled the complete S. psammophila mitochondrial genome using Pacbio HiFi third-generation sequencing data. The genome was found to be a typical single circular structure, with a total length of 715,555 bp and a GC content of 44.89%. We annotated 33 unique protein-coding genes (PCGs), which included 24 core mitochondrial genes and 9 variable genes, as well as 18 tRNA genes (5 of which were multicopy genes) and 3 rRNA genes. Comparative analysis of the PCGs from the mitochondrial genomes of S. psammophila, Populus deltoides, Populus simonii, Salix wilsonii, and Salix suchowensis revealed that these genes are relatively conserved within the Salicaceae family, with variability primarily occurring in the ribosomal protein genes. The absence of the rps14, which encodes a ribosomal protein, may have played a role in the evolution of stress tolerance in Salicaceae plants. Additionally, we identified 232 SSRs, 19 tandem repeat sequences, and 236 dispersed repeat sequences in the S. psammophila mitochondrial genome, with palindromic and forward repeats being the most abundant. The longest palindromic repeat measured 260 bp, while the longest forward repeat was 86,068 bp. Furthermore, 324 potential RNA editing sites were discovered, all involving C-to-U edits, with the nad4 having the highest number of edits. These findings provide valuable insights into the phylogenetic and genetic research of Salicaceae plants.

The complete chloroplast genome of Fuchsia standishii J. Harrison, 1840 (Onagraceae) from Yunnan, China

Fuchsia standishii J. Harrison, 1840, a perennial shrub, is renowned for its vividly colored and uniquely shaped blooms, which have an extended flowering season. Commonly cultivated as an ornamental potted plant, it is utilized in traditional Chinese medicine. In this study, we successfully sequenced and assembled the complete chloroplast genome of F. standishii using high-throughput Illumina sequencing technology. The assembled chloroplast genome displays a typical quadripartite structure, with a total length of 156,391 bp. It consists of a pair of inverted repeat regions (IRs), each measuring 25,069 bp, separated by a large single-copy region (LSC) of 87,754 bp and a small single-copy region (SSC) of 18,499 bp. The overall GC content of the genome is 37.60%. The genome includes a total of 129 genes, comprising 84 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenetic analysis of 17 complete chloroplast genomes revealed that F. standishii forms a monophyletic group with the entire Circaea. This study provides a molecular foundation for future phylogenetic research on Fuchsia.

Unveiling the Understudied: a Look at Phylogenetic Research on Mollusks in Brazil

Unveiling the Understudied: a Look at Phylogenetic Research on Mollusks in Brazil

Genetic Variability in Mediterranean Coastal Ecosystems: Insights into Ostrea spp. (Bivalvia: Ostreidae).

Oysters are sessile, filter-feeding bivalve molluscs widely distributed in estuarine and coastal habitats worldwide. They constitute a valuable resource for fisheries and extensive aquaculture and provide essential ecological services. Yet, their genetic diversity and distribution remain understudied. The variability in shell morphology complicates species classification, which is influenced by environmental and genetic factors. Although molecular phylogenetics research has refined oyster taxonomy and identified approximately 100 extant species, numerous taxonomic uncertainties persist. In the present study, we aimed to document the occurrence of small flat oysters of the genus Ostrea along the Mediterranean coastal areas of Liguria and Sardinia (Italy). Specifically, 16S rRNA sequence data were used to identify Ostrea species. Our findings offer novel insights into the O. stentina species complex and O. neostentina, a new species in the Mediterranean coastal areas of Italy. The study data further our understanding of Ostrea species diversity, distribution, and evolutionary patterns.

Analysis of Codon Usage Bias in the Plastid Genome of Diplandrorchis sinica (Orchidaceae).

In order to understand the bias and main affecting factors of codon usage in the plastid genome of Diplandrorchis sinica, which is a rare and endangered plant species in the Orchidaceae family, the complete plastid genome sequence of D. sinica was downloaded from the GenBank database and 20 protein-coding sequences that met the analysis requirements were finally selected. The GC content, length of the amino acid (Laa), relative synonymous codon usage (RSCU), and effective number of codon (ENC) of each gene and codon were calculated using the CodonW and EMBOSS online programs. Neutral plot analysis, ENC-plot analysis, PR2-plot analysis, and correspondence analysis were performed using Origin Pro 2024 software, and correlation analysis between various indicators was performed using SPSS 23.0 software. The results showed that the third base of the codon in the plastid genome of D. sinica was rich in A and T, with a GC3 content of 27%, which was lower than that of GC1 (45%) and GC2 (39%). The ENC value ranged from 35 to 57, with an average of 47. The codon usage bias was relatively low, and there was a significant positive correlation between ENC and GC3. There were a total of 32 codons with RSCU values greater than 1, of which 30 ended with either A or U. There were a total of nine optimal codons identified, namely, UCU, UCC, UCA, GCA, UUG, AUA, CGU, CGA, and GGU. This study indicated that the dominant factor affecting codon usage bias in the plastid genome of D. sinica was natural selection pressure, while the impact of base mutations was limited. The codon usage patterns were not closely related to gene types, and the distribution of photosynthetic system genes and ribosomal protein-coding gene loci was relatively scattered, indicating significant differences in the usage patterns of these gene codons. In addition, the codon usage patterns may not be related to whether the plant is a photosynthetic autotrophic or heterotrophic nutritional type. The results of this study could provide scientific references for the genomic evolution and phylogenetic research of plant species in the family Orchidaceae.

Characterization and phylogenetic analysis of the complete mitochondrial genome of the red alga, Gracilaria eucheumatoides Harvey 1860 (Gracilariales: Gracilariaceae) from Vietnam

The marine red alga, Gracilaria eucheumatoides, is economically significant for its agar production and pharmacologically active compounds. This study reveals its complete mitochondrial genome (mitogenome), sequenced using Illumina’s next-generation technology. The mitogenome is a 25,909 bp circular molecule with a G + C content of 27.21%, comprising 24 protein-coding genes, two ribosomal RNA genes, 24 transfer RNA genes, and one open reading frame (ORF) with an unidentified function. Both gene structure and composition are highly conserved within Gracilaria. The phylogenetic analyses fully support a close relationship of G. eucheumatoides with other Gracilaria species, as well as its sister relationship with G. urvillei. This mitogenome sequencing effort of G. eucheumatoides provides crucial data for future phylogenetic research on marine red algae.