Molecular Phylogenetic Research Articles

Genetic species concept as applied to multilocus nuclear data

Using the example of multiple species groups and species complexes, it is empirically shown that the resolving power of a set of 10–20 nuclear loci is insufficient for the study of their genetic differentiation. For the adequate analysis of phylogenetic relationships (including reticulation events) and assessment of divergence levels within such groups of closely related species, it is necessary to multiply the number of nuclear loci and transit to high-throughput next-generation deep sequencing. However, the question of the genomic coverage required for the purposes of such study remains open. In other words, exactly how many genes in a set are needed to measure the genetic distance resolving the relationships between branches on the phylogenetic tree reconstruction of a complex of closely related species? We chose protein-coding sequences as a standard set of markers. Distances for 160–180 genes with a combined length of 270 000–300 000 bp were used to estimate the divergence levels of closely related mammalian species. In most cases, the interspecific distances are within the 0.15–0.75% range (median of 0.33%). The range of distances between semi-species is 0.12–0.28% (median of 0.14%). Intraspecific distances are always lower than 0.11%. Rodents show higher values of interspecific distances, 0.25–2.3% (median of 0.72%); distances between half-species range from 0.1 to 0.35%. To determine the number of nuclear loci and their combined length sufficient for the calculation of a genetic distance, we use simulations based on a model that included the following parameters: the average rate of gene evolution, its dispersion, and the level of polymorphism in the modern and ancestral populations. We performed a preliminary analysis of the distribution of loci evolution rates among mammalian taxa based on the data on ~50 thousand nuclear markers. It is shown that a relative error of 10–15%, comparable to the same value for mitochondrial distances between close species based on individual genes (approximately 1000 bp in length), is achieved using approximately 100 loci of 300 bp in length. Based on these data, we propose the following working hypothesis: the threshold of interspecific/intraspecific genetic distance calculated on the basis of the exons most frequently used in mammalian molecular phylogenetics is approximately 0.15%. This hypothesis assumes a species rank for the forms in statu nascendi. It should be noted that not all “good” species have significant genetic distances, since in some cases reproductive barriers form faster than substitutions accumulate in the genome.

Abstract B037: Expression of MRTFA facilitates an immunosuppressive tumor microenvironment via upregulation of VSIR

Abstract Breast cancer, the second highest cause of cancer-related deaths in women, accounts for 31% of female cancer diagnoses. African American women have lower survival rates than White American women, influenced by both biological factors (age, family history, genetic factors, tumor biology) and social determinants (socio-economic status, insurance status, health care access). However, precise biological determinants remain unclear. The primary reason for breast cancer mortality is metastasis to organs like the lung, liver, and brain, with transcription factors playing a key role in this process. Myocardin related transcription factor A/B (MRTFA/B) are co-activators of serum-response factor (SRF), and the MRTF-SRF complex promotes breast cancer cell migration, invasion, and metastasis by regulating genes involved in actin cytoskeleton remodeling. MRTFA also supports tumor growth by modulating cancer-associated fibroblasts (CAFs) and remodeling the extracellular matrix (ECM) in the tumor microenvironment. While the pro-metastatic role of MRTFA/B is established in vitro and in mice, their impact on human cancer progression and metastasis requires further investigation. Therefore, understanding MRTFA's role in breast cancer metastasis is crucial for improving patient outcomes, making it essential to investigate MRTFA/B expression patterns in both tumor cells and the tumor microenvironment (TME). To explore the clinical, demographic, tumor-intrinsic, and tumor microenvironmental patterns of MRTFA/B’s expression and activation, we utilized multiplex imaging methods on multiple racially diverse tissue microarrays (TMA) and bioinformatics analyses of The Cancer Genome Atlas (TCGA), Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), and available single-cell RNA sequencing datasets. Strikingly, MRTFA expression levels were higher in African American patients than in White American patients. Next, we investigated MRTFA expression patterns in the TME by using single-cell sequencing databases and found more abundant MRTFA expression in dendritic cells (DCs) within the TME compared to any other cell subtype. Moreover, our multiplex-imaging of tumor microarray (TMA) samples showed prominent MRTFA expression in HLA-DRA+CD45+ cells, indicative of antigen-presenting cells (APC). Notably, public single-cell RNA sequencing data indicated that breast cancer DCs strongly express the V-set immunoregulatory receptor (VSIR), an immune checkpoint protein, implying the immunosuppressive nature of the TME and we found that this increased VSIR expression is mediated by the MRTF-SRF complex. These findings suggest that DCs expressing MRTFA in breast cancer microenvironment contribute to creating the immunosuppressive TME via upregulation of VSIR expression, resulting in racial breast cancer disparities. Citation Format: Kihak Lee, Stephanie M. Wilk, Alexa M. Gajda, Mohamed Haloul, Virgilia Macias, Elizabeth L. Wiley, Zhengjia Chen, Xinyi Liu, Xiaowei Wang, Maria Sverdlov, Kent F. Hoskins, Ekrem Emrah Er. Expression of MRTFA facilitates an immunosuppressive tumor microenvironment via upregulation of VSIR [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B037.

Widely acclaimed but poorly named: Phylogeny and systematics of the African daisy genus Dimorphotheca (Asteraceae, Calenduleae)

AbstractPhylogenetic relationships in the South African daisy genus Dimorphotheca have long been uncertain, with the taxonomy of the genus relying on a few morphological traits, most prominently capitulum sexual system (e.g., cypsela type) and ray colour, which may not be evolutionarily conserved. Here we present the first well‐sampled molecular phylogeny of Dimorphotheca, based on nuclear ribosomal (ITS, ETS) and plastid trnL‐trnF region DNA sequences from multiple accessions per species. Although the relationships suggested by these markers are broadly congruent, we do find some instances of incongruence which we resolve using a combined decomposition and deletion approach. Using our best estimate of phylogenetic relationships, we reconstruct the evolution of capitulum fertility and ray colour to assess the evolutionary conservatism of these traits and their taxonomic utility. We find support for the monophyly of Dimorphotheca, excluding the recently segregated Osteospermum polypterum, and our data thus support the modern, enlarged circumscription of the genus incorporating the former genus Castalis and Osteospermum sect. Acanthotheca and O. sect. Blaxium. Major subclades within Dimorphotheca are largely cohesive in terms of geographic distribution and morphological traits such as growth form and cypsela structure. While many species are resolved as monophyletic, the polyphyly of a few species suggests a need for taxonomic re‐evaluation. On the basis of both morphological and molecular data, we describe one new species, and elevate one variety to species level. A full taxonomic key to the enlarged genus is presented for the first time. Ancestral reconstructions show that capitulum sexual system and ray lamina colour are not evolutionarily conserved and that neither can therefore be used to delimit major lineages within Dimorphotheca. While our findings resolve some taxonomic problems, they also highlight the need for further species‐level taxonomic work on Dimorphotheca.

Deciphering the Role of ASPM in Breast Cancer: A Comprehensive Multicohort Study

Background: Assembly factor for spindle microtubules (ASPM) has gained significant attention in cancer research due to its association with tumor growth and progression. Through the analysis of large-scale genomic datasets, ASPM has been identified as the top upregulated gene in breast cancer (BC), characterized by high proliferation. This multicohort study aimed to investigate the clinicopathological and prognostic significance of ASPM mRNA and protein expression in BC. Methods: ASPM mRNA expression was assessed using the Cancer Genome Atlas (TCGA) BC cohort and has been further validated in the Molecular Taxonomy of BC International Consortium (METABRIC) (n = 1980), The Uppsala cohort (n = 249), in addition to the combined multicentric cohort (n = 7252). ASPM protein expression was evaluated in a large BC cohort (n = 1300) using immunohistochemistry. The correlations between ASPM expression, clinicopathological parameters, molecular subtypes and outcome were assessed. The response to taxane treatment was compared to the clinical prognosis of ASPM using the ROC plotter. Results: High ASPM mRNA and protein expression were significantly associated with aggressive BC features and poor survival across all cohorts. The association with poor outcomes was maintained in the adjuvant chemotherapy and radio-therapy-treated patients. Responders to taxane treatment showed significantly elevated ASPM levels compared to non-responders. Conclusions: High ASPM expression predicts poor prognosis in BC. It may play a role in treatment resistance within a specific subgroup of patients. Further clinical trials are warranted to explore the potential of ASPM as a target for therapeutic interventions in cancer.

Elymus multiramosus (Poaceae), a new species from the north-western Qinghai-Tibetan Plateau, China

A new species from China, Elymus multiramosus Y.C. Zhang, sp. nov. is described and illustrated herein, based on morphological characters and molecular phylogenetic analysis. The taxonomic descriptions of E. multiramosus and the comparison with related species are presented. The taxonomic distinctiveness of this new species was inferred by Maximum Likelihood (ML) analysis and Bayesian phylogenetic analysis, based on the complete chloroplast genome sequence. It is assigned to the Elymus section and bears similarity to Elymus nutans Griseb. However, it can be easily distinguished from other species by its compound spike, in contrast to the simple spike inflorescence typical of those species. The compound spike is characterised by rhachillas that are extended at the base of the main axis, giving rise to 3–6 mini-spike-like branches. Notably, these branches significantly increase in length from the top towards the bottom of the compound spike. In the molecular phylogeny, Elymus multiramosus from Qinghai, north-western China, is phylogenetically positioned as a distinct lineage. The lineage comprising Elymus sinosubmuticus from Sichuan, east of the Tibetan Plateau and Elymus nutans from the Himalayas forms a sister group to Elymus multiramosus, suggesting that these three species share a common ancestor that is distinct from the lineage leading to Elymus atratus from Gansu, north of the Tibetan Plateau.

An insight into the molecular phylogeny of Drepanidae (Lepidoptera) with an emphasis on the European fauna

An insight into the molecular phylogeny of Drepanidae (Lepidoptera) with an emphasis on the European fauna

Morphological, molecular and 3D synchrotron X-ray tomographic characterizations of Helicascus satunensis sp. nov., a novel mangrove fungus.

A new species of Helicascus satunensis sp. nov. was collected on mature dead fruits of the Nypa palm in Satun Province, southern Thailand. Its morphological characteristics are similar to those of the genus Helicascus. Recently, a genus Helicascus with three species from marine habitats worldwide was studied. The morphology of this fungus was investigated and combined with multigene sequence analyzes of small subunit (SSU), large subunit (LSU), internal transcribed spacer (ITS) ribosomal DNA, translation elongation factor 1-alpha (TEF-1α) and RNA polymerase II (RPB2) genes. Morphologically, H. satunensis sp. nov. is characterized by semi-immersed, lenticular ascomata, multilocules, a bitunicate ascus and smooth, obovoid, dark brown ascospores that are one-septate and unequally two-celled. In addition, 3D visualization using synchrotron X-ray tomography was performed to investigate the interaction between fruiting body and substrata. Molecular phylogeny with multigene revealed that H. satunensis sp. nov. belongs to the family Morosphaeriaceae, order Pleosporales, class Dothideomycetes. Furthermore, H. satunensis sp. nov. forms a well-supported clade with Helicascus species described from marine habitats. Based on the unique morphological and molecular evidence, we propose this fungus, H. satunensis sp. nov., as a new species for Helicascus.

Idiopyrgus Pilsbry, 1911 (Gastropoda, Tomichiidae): a relict genus radiating into subterranean environments

The freshwater gastropod fauna in Brazil presently consists of circa 180 known species, though this is deemed an underestimate. The little-studied cavern faunas have been considered a potential source of undescribed species, particularly regarding the Truncatelloidea. Here, based on new collection efforts in caves in Bahia state, Brazil, we describe two new troglobitic species of Idiopyrgus (Tomichiidae): Idiopyrgus eowynaesp. nov. and Idiopyrgus meriadocisp. nov. We improve upon the previous molecular phylogeny of this genus and take the opportunity to reclassify Spiripockia umbraticola Simone & Salvador, 2021, as Idiopyrgus umbraticola (Simone & Salvador, 2021), comb. nov. The genus Idiopyrgus now contains ten species, reinforcing the presence of Tomichiidae in Brazil as a relict lineage that largely radiated into cave environments. Furthermore, considering that so far only snapshots of their biology are known, we have collated all the information currently available from the literature and field observations on the cavernicolous species of Idiopyrgus. Notably, due to human action in the area where the two new species have been found, they can already be considered vulnerable.

Understanding the anatomical diversity of leaves in the Aspicarpoid clade: New insights for Malpighiaceae systematics

The Aspicarpoid clade represents a strongly supported group within the Stigmaphylloid lineage. The group is composed of four neotropical genera: Aspicarpa Rich., Gaudichaudia Kunth, Janusia A.Juss. and Peregrina W.R.Anderson. In this study, we studied the utility of leaf anatomy characters to support groups recovered in molecular phylogenies and define synapomorphies that can be used in future infra- and supra-generic classifications. Camarea axillaris A.St.-Hil. (1823: 10) and Cottsia Dubard & Dop (1908: 20) were used as outgroups for comparison. Dry leaf samples were re-hydrated, sectioned, stained, and analyzed using a microscope and a stereomicroscope. Characters such as presence and absence of glands, their location and morphotype, petiole and midrib contour, presence of trichomes, accessory bundles, vascular system organization and mesophyll type were utilized for species comparison, showing high taxonomic value for the group. Leaf glands, accessory bundles, sheath extension in the mesophyll and presence of druses and prismatic crystals were the most valuable characters in an evolutionary approach for the clade. Our work confirms the power of leaf anatomy as a taxonomic and evolutionary tool in Malpighiaceae Juss. (1789: 252), as well as its contribution to the delimitation of phylogenetic groups in the Aspicarpoid clade.

A preliminary phylogeny of Malachiinae (Coleoptera, Malachiidae): From multiple genes to whole genomics

AbstractMalachiinae (Coleoptera: Malachiidae), commonly known as true soft‐winged flower beetles, are widely distributed across the globe except New Zealand. It is the largest subfamily of Cleroidea (over 3000 species) and is currently divided into seven tribes, among which the relationships are hard to assess due to their bizarre morphological modifications in males. Although a few molecular phylogenetics were attempted, they were all constructed on basis of four or five short nucleotide fragments, which may not contain enough phylogenetic information, thereby resulting in unclear relationships. To investigate the phylogenetic relationships among the tribes within Malachiinae, low‐coverage whole genomes of 26 species from the superfamily Cleroidea were sequenced and analysed, including 22 species of Malachiinae. The mitochondrial genomes (mitogenomes), nuclear genes (18S, 28S rRNA) and universal single‐copy orthologs (USCOs) were obtained as molecular markers from low‐coverage sequencing data. A total of 24 complete or nearly complete mitochondrial genomes of Malachiidae species were annotated and analysed. Further combined the newly sequenced data and those available in the public database, four different data matrices were analysed by different methods to reconstruct the phylogeny of Malachiinae. The results indicated that these phylogenetic analyses produced consistent topologies, and the phylogenetic relationships within Malachiinae were recovered as (Illopini + (Troglopini + (Colotini + Apalochrini))) + (Ebaeini + (Attalini + Malachiini)).

Assessing the effect of model specification and prior sensitivity on Bayesian tests of temporal signal.

Our understanding of the evolution of many microbes has been revolutionised by the molecular clock, a statistical tool to infer evolutionary rates and timescales from analyses of biomolecular sequences. In all molecular clock models, evolutionary rates and times are jointly unidentifiable and 'calibration' information must therefore be used. For many organisms, sequences sampled at different time points can be employed for such calibration. Before attempting to do so, it is recommended to verify that the data carry sufficient information for molecular dating, a practice referred to as evaluation of temporal signal. Recently, a fully Bayesian approach, BETS (Bayesian Evaluation of Temporal Signal), was proposed to overcome known limitations of other commonly used techniques such as root-to-tip regression or date randomisation tests. BETS requires the specification of a full Bayesian phylogenetic model, posing several considerations for untangling the impact of model choice on the detection of temporal signal. Here, we aimed to (i) explore the effect of molecular clock model and tree prior specification on the results of BETS and (ii) provide guidelines for improving our confidence in molecular clock estimates. Using microbial molecular sequence data sets and simulation experiments, we assess the impact of the tree prior and its hyperparameters on the accuracy of temporal signal detection. In particular, highly informative priors that are inconsistent with the data can result in the incorrect detection of temporal signal. In consequence, we recommend: (i) using prior predictive simulations to determine whether the prior generates a reasonable expectation of parameters of interest, such as the evolutionary rate and age of the root node, (ii) conducting prior sensitivity analyses to assess the robustness of the posterior to the choice of prior, and (iii) selecting a molecular clock model that reasonably describes the evolutionary process.

Identification and Characterization of EIN3/EIL Transcription Factor Family Members in Pinus massoniana Lamb.

Transcription factors refer to types of proteins that perform significant functions in the process of gene expression regulation. The ethylene insensitive 3/ethylene insensitive 3-like (EIN3/EIL) family, functioning as significant transcription factors regulating ethylene, plays a critical role in the growth and development of plants and participates in the plant’s response to diverse environmental stresses. Pinus massoniana is an excellent native tree with high economic and ecological value. However, the study of EIN3/EIL genes in gymnosperms, for instance, P. massoniana, is still relatively limited. In this research, four putative EIN3/EIL genes were identified in the transcriptome of P. massoniana. Bioinformatics analysis showed that PmEIL genes contain a highly conserved EIN3 domain and other structural features of acidic, proline-rich and glutamine-rich sites. The molecular evolution tree analysis demonstrated that the EIN3/EIL family was partitioned into three categories (A, B, and C), and the number, type, and distribution of conserved motifs grouped in one category were similar. The results of qRT-PCR indicated that the expression levels of PmEIL genes were markedly elevated in needles compared to other tissues. Through the analysis of expression patterns of the PmEIL genes under various stress treatments, it was found that the PmEIL genes could participate in plant hormone stimulation induction, osmosis, drought and other response processes. In addition, PmEIL is a nuclear localization protein. PmEIL1, PmEIL3, and PmEIL4 are transcriptional activators, while PmEIL2 is a transcriptional suppressor. This research provides a basis for further elucidating the function of EIN3/EIL transcription factors in growth, development and stress response of P. massoniana.

Molecular phylogeny and morphological identification of two species of Diplostomum (Digenea: Diplostomidae) in fishes from the Ganga River, India: an integrative taxonomic approach

Molecular phylogeny and morphological identification of two species of Diplostomum (Digenea: Diplostomidae) in fishes from the Ganga River, India: an integrative taxonomic approach

Advancing in molecular taxonomy: DNA barcode, a tool to resolve taxonomy and phylogeny of family euphorbiaceous

Advancing in molecular taxonomy: DNA barcode, a tool to resolve taxonomy and phylogeny of family euphorbiaceous

A new leaf inhabiting ascomycete from the Jurassic (ca 170 Mya) of Yorkshire, UK, and insights into the appearance and diversification of filamentous Ascomycota

Leaf-associated fungi, the fungi that depend on leaves to sporulate, have a rich Cenozoic record, however their earlier diversity is poorly characterized. Here we describe Harristroma eboracense gen. et sp. nov., a Middle Jurassic leaf-associated fungus colonizing the leaf cuticle of Nilssonia tenuicaulis (cycadophyte). To place our newly described species into a picture of the diversification of Mesozoic fungi, we reassess fossils with leaf-associated stromata in the context of fungal molecular phylogeny. Being melanized, with radiate stromata, and on leaves, H. eboracense and other fossils from the Jurassic and earlier periods are probably related to filamentous Ascomycota in the superclass Leotiomyceta. Characters needed for further resolution of leaf-associated fungal biology and classification, such as the presence of an ostiole for spore discharge and appressoria for entry into leaf tissue first appear in the Mesozoic fossil record. Among Early Cretaceous fossils, Spataporthe taylorii represents the oldest unambiguous evidence of perithecial Sordariomycetes while Protographum luttrellii and Bleximothyrium ostiolatum are the oldest Dothideomycetes thyriothecia. Environmental observations show that broad leaved gymnosperms (especially cycadophytes) growing in warm temperate wet forests might have been the first environment for the radiation of Leotiomyceta.

Phylogenetic evaluation and genotypic identification of burn-related Pseudomonas aeruginosa strains isolated from post-burn human infections during hospitalization.

Cutaneous burn trauma, compromise of dermal layers and immune defense system is a physical and fiscal burden on healthcare systems. Burn-wound infections are a serious complication of thermal-injury and contribute significantly to care burden. After burn-induced trauma, sepsis by Pseudomonas aeruginosa impairs patient recovery and contributes to mortality and morbidity. Past studies show positive correlation between detection of Pseudomonas species and healing-impaired traumatic wounds. P. aeruginosa is a resilient opportunistic human pathogen and a nosocomial agent involved in pathology of healing-impaired wounds, especially in burn-patients. Expansive array of virulence determinants have resulted in gentamicin- and silver-resistant P. aeruginosa outbreaks. Knowledge of molecular dynamics and phylogeny of P. aeruginosa associated with burn-wounds is limited. Therefore, we conducted whole-genome sequencing for genotyping and phylogenetic analysis of P. aeruginosa burn-associated strains (n=19) isolated from 7 burn cases during hospitalization. Comparison of genetic features in P. aeruginosa strains in the core genome and mobilome detected genetic variations within some clonal infections overtime. Genetic variations were observed among different burn cases, with some features identified in severe lung infections. Polyclonal infections were also observed, with differing genotypes and virulence potentials, highlighting the importance of reasoned sampling of isolates for clinical testing.

Phenotypic and molecular characterization of Prototheca wickerhamii from a Brazilian case of human systemic protothecosis.

The genus Prototheca (alga) comprises a unique group of achlorophyllic saprotrophic and mammalian pathogen species. Despite its rare occurrence in humans and animals, protothecosis is considered an emerging clinical entity with relevance in immunocompromised patients. In this study, the characterization of spherical structures with endospores recovered from a blood culture in an HIV patient was investigated using phenotypic and molecular methodologies. On 2% Sabouraud dextrose agar, the isolate displayed morphological and biochemical characteristics found on isolates identified as Prototheca wickerhamii. To validate these analyses, molecular phylogeny of the internal transcript space (ITS) partial gene confirmed the identity of the isolate as P. wickerhamii. This is the first case of systemic human protothecosis in Brazil. The present case of human Prototheca and those reported in the medical literature highlight the need for novel methodologies to identify pathogenic algae in the clinical laboratory, improving in this way the diagnosis and treatment of this group of neglected pathogens.

Legacy molecular phylogenetics suggests restricting the concept of Melandryidae and resurrecting Osphyidae (Coleoptera: Tenebrionoidea)

The superfamily Tenebrionoidea is one of the most challenging clades in the beetle tree-of-life owing to its vast species richness and complex taxonomic history. Within this group, the family Melandryidae has long been overlooked and its systematics remains poorly known. Using available sequence data, we infer the most comprehensive phylogeny of Melandryidae to date. Our results support the polyphyly of Melandryidae with three independent clades spread across Tenebrionoidea. To accommodate these results, we restrict the status of Melandryidae and resurrect the family Osphyidaestat. rev. The third clade corresponding to the tribe Serropalpini pro parte is placed as incertae sedis within Tenebrionoidea pending further investigation and additional taxon sampling to resolve its phylogenetic placement.

Diversity of Pleosporalean Fungi Isolated from Rice (Oryza sativa L.) in Northern Thailand and Descriptions of Five New Species

Pleosporales represents the largest order within the class Dothideomycetes (Fungi), comprising phytopathogenic, saprobic, and endophytic taxa with a widespread presence in terrestrial and aquatic environments. Rice (Oryza sativa) is a primary economic crop in numerous tropical countries, particularly in Thailand. Studying fungal species associated with rice holds the potential to enhance our understanding of fungal diversity, lifestyles, and biology of rice, offering valuable insights for future research aimed at disease management and yield improvement. Thirty-nine pleosporalean isolates were obtained from various parts of rice plants collected across diverse regions in Chiang Rai Province, Thailand. Species identification involved a combination of morphology and molecular phylogeny, utilizing multi-locus sequence analyses of the ITS, LSU, SSU, gapdh, rpb2, tef1, and tub2 genes. The isolates were identified in 18 taxa distributed across five families and ten genera, including five new species (Bipolaris chiangraiensis, Ophiosphaerella oryzae, Paraphaeosphaeria oryzae, Pyrenochaetopsis oryzicola, and Setophoma oryzicola). Additionally, six new host records and two new geographical records are documented. Photoplates, detailed morphological descriptions, and phylogenetic trees are provided to elucidate the placement of both known and novel taxa.

Journey to the West: migration patterns of the riparian montane genus Myricaria

Myricaria Desv. (Tamaricaceae) is a genus of riparian plants found in montane regions throughout Eurasia. We present molecular phylogenies covering the entire Eurasian range of the genus using the chloroplast interspacer region psbA-trnH, the chloroplast region trnL-trnF, and the nuclear ribosomal Internal Transcribed Spacer (ITS). Biogeographical analyses of the DNA sequencing data based on Takhtajan's Floristic Provinces using a Bayesian Binary Markov Chain Monte Carlo reconstruction show that the origin of Myricaria is the Tibetan Floristic Province, specifically in the Qinghai-Tibetan Plateau. A molecular clock analysis was also performed. We estimate that the crown age of Myricaria is around 22.8 Ma and that the common ancestor of all European Myricaria occurred around 8.8 Ma ago. By covering the entire native range of the genus, our analyses confirm previous hypotheses on the origin and migration patterns of Myricaria, namely a central Asian centre of origin, followed by a westward migration to Europe via the central Asian mountain ranges, the Caucasus, and Eastern Europe. The divergence times and migration routes of Myricaria are remarkably similar to that of the genus Hippophae L.