Multilocus Data Research Articles

First report of Morchella galilaea, an autumn species from Pakistan, based on multilocus DNA sequences, light microscopy, and scanning electron microscopy analyses.

Morchella is highly prized for its distinct and delicious taste, making it one of the most sought-after and valuable macrofungi. Despite Pakistan exporting morels to various European countries, Morchella's diversity in this South Asian country has not been cataloged using multilocus DNA sequence data. Realizing the need for their scientific identity, various collections were commissioned, including those from the low and high altitudinal zones of the Charsadda, Swat, and Poonch districts of Pakistan during autumn of 2015 through 2019. Specimens were identified by sequencing the internal transcribed spacer (ITS) region and portions of the RNA polymerase II largest subunit (RPB1), second largest subunit (RPB2), and translation elongation factor 1-α (TEF1) loci. Multigene molecular phylogenetic analysis revealed the autumnal collections were Morchella galilaea Masaphy & Clowez. The species was previously documented in the United States, China, Israel, and Turkey. A detailed taxonomic description, light and scanning electron microscopy, and multigene molecular phylogenetic analyses of the species are reported here for the first time from Pakistan. The study underscores the necessity for further surveys of unexplored areas of Pakistan and systematics of Morchella to augment species diversity and their geographic distribution. RESEARCH HIGHLIGHTS: Specimens of Morchella were collected from low and high altitudinal zones in Pakistan during the autumn. Specimens were assessed using multigene (ITS, RPB1, RPB2, and TEF1) molecular phylogenetic analyses for the first time in Pakistan. The specimens were identified as Morchella galilaea based on multigene molecular phylogenetic analysis. Updated taxonomic descriptions of macro- and microanatomical characters were provided for clarity and precision. Hitherto-unreported shapes of paraphyses and acroparaphyses are observed and thoroughly reported. Scanning electron microscopy (SEM) of an ascospore is provided.

COI Barcodes combined with multilocus data for representative Aporia taxa shed light on speciation in the high altitude Irano-Turanian mountain plateaus (Lepidoptera: Pieridae)

Even though the high plateaus of Qinghai-Tibet and Iran share many faunal elements, the historical biogeography of the species present in this area are not very well understood. We present a complete COI barcode library for Aporia Hübner and a first comprehensive phylogeny for the genus including all known species and majority of subspecies using ten available genes (COI-COII, ND1, ND5, Cytb, EF-1a, Wg, 16S, 28S-D2/D3 and 28S-D8). We then focus on A. leucodice (Eversmann, 1843) and related taxa in order to resolve some long-standing taxonomic issues in this species-group. Based on DNA sequence data as well as morphology, we raise Aporia illumina (Grum-Grshimailo 1890) stat. nov. (= pseudoillumina Tshikolovets 2021 syn. nov.) as a distinct species and designate a lectotype; synonymize Aporia leucodice leucodice Eversmann, 1843 (= A. l. morosevitshae Sheljuzhko, 1908 syn. nov.); and describe a new species, Aporia ahura sp. nov., from the Central Alborz Mountains in northern Iran.

Establishing species boundaries in Bornean geckos.

Species delimitation using mitochondrial DNA (mtDNA) remains an important and accessible approach for discovering and delimiting species. However, delimiting species with a single locus (e.g. DNA barcoding) is biased towards overestimating species diversity. The highly diverse gecko genus Cyrtodactylus is one such group where delimitation using mtDNA remains the paradigm. In this study, we use genomic data to test putative species boundaries established using mtDNA within three recognized species of Cyrtodactylus on the island of Borneo. We predict that multi-locus genomic data will estimate fewer species than mtDNA, which could have important ramifications for the species diversity within the genus. We aim to (i) investigate the correspondence between species delimitations using mtDNA and genomic data, (ii) infer species trees for each target species, and (iii) quantify gene flow and identify migration patterns to assess population connectivity. We find that species diversity is overestimated and that species boundaries differ between mtDNA and nuclear data. This underscores the value of using genomic data to reassess mtDNA-based species delimitations for taxa lacking clear species boundaries. We expect the number of recognized species within Cyrtodactylus to continue increasing, but, when possible, genomic data should be included to inform more accurate species boundaries.

Challenges of molecular barcode-based identification of earthworm specimens for biodiversity assessment

Specimen identification at the species level is a critical challenge for understanding community structure and conserving biodiversity. The use of mitochondrial DNA barcodes, in addition to morphology, has proven to be a useful tool for earthworm identification, but it has also raised difficulties. Thus, approaches to delineating molecular operational taxonomic units (MOTUs) from cytochrome c oxidase subunit 1 (COI) or 16S rDNA sequence data often reveal more mitochondrial lineages than morphospecies, raising the question of whether these MOTUs should be used as taxonomic entities in community structure studies. Here, we used a newly acquired dataset of 576 COI barcodes of earthworms from Metropolitan France that were clustered in 36 MOTUS, corresponding to 21 morphospecies. We also incorporated data gathered from the literature to investigate this question. In order to match our MOTUs with already-described mitochondrial lineages, we downloaded reference sequences from the GenBank and BOLD platforms. In light of the difficulties encountered in recovering these sequences, we recommend that any new mitochondrial lineage described in a study be named consistently with previous works. Next, we analyzed the biological, ecological, and molecular data available in the literature on the different mitochondrial lineages that matched our MOTUs in order to determine if there was a consensus for species delimitation. Although the study specimens mainly belong to the Lumbricidae, which is one of the most studied families of earthworms, the data are often missing to determine if the MOTUs correspond to different species. Pending revision of the taxonomy, MOTUs for which mitochondrial divergence has been confirmed by morphological differences should be considered distinct taxonomic entities in community structure studies. In the absence of morphological differences and pending more data, we propose to distinguish for these analyses, within sexually reproducing morphospecies, the MOTUs for which mitochondrial divergence has been confirmed by multilocus nuclear data, while in the case of reproduction by parthenogenesis, ecological differences between MOTUs are necessary to consider them as different taxonomic entities.

Tropical Logistic Regression Model on Space of Phylogenetic Trees

Classification of gene trees is an important task both in the analysis of multi-locus phylogenetic data, and assessment of the convergence of Markov Chain Monte Carlo (MCMC) analyses used in Bayesian phylogenetic tree reconstruction. The logistic regression model is one of the most popular classification models in statistical learning, thanks to its computational speed and interpretability. However, it is not appropriate to directly apply the standard logistic regression model to a set of phylogenetic trees, as the space of phylogenetic trees is non-Euclidean and thus contradicts the standard assumptions on covariates. It is well-known in tropical geometry and phylogenetics that the space of phylogenetic trees is a tropical linear space in terms of the max-plus algebra. Therefore, in this paper, we propose an analogue approach of the logistic regression model in the setting of tropical geometry. Our proposed method outperforms classical logistic regression in terms of Area under the ROC Curve in numerical examples, including with data generated by the multi-species coalescent model. Theoretical properties such as statistical consistency have been proved and generalization error rates have been derived. Finally, our classification algorithm is proposed as an MCMC convergence criterion for Mr Bayes. Unlike the convergence metric used by Mr Bayes which is only dependent on tree topologies, our method is sensitive to branch lengths and therefore provides a more robust metric for convergence. In a test case, it is illustrated that the tropical logistic regression can differentiate between two independently run MCMC chains, even when the standard metric cannot.

Evolutionary relationships in the African frog family Ptychadenidae, including the first molecular analysis, range extension, and distribution modelling of the monotypic genus Lanzarana

ABSTRACT The family Ptychadenidae contains three ecologically and morphologically distinct genera: the widespread, species-rich and above-ground dwelling Ptychadena, the less widespread and diverse, burrowing Hildebrandtia, and the little-known, burrowing, monotypic Lanzarana, endemic to Somalia. Previous morphological studies placed Lanzarana in a sister position to Hildebrandtia and these two genera as sister to Ptychadena. However, our analyses of mitochondrial and multilocus nuclear DNA data revealed Lanzarana as a sister lineage to Ptychadena (divergence ∼28 Mya), and Hildebrandtia sister to them (∼42 Mya). This suggests that the common ancestor of ptychadenids may have exhibited a burrowing lifestyle similar to Hildebrandtia and Lanzarana, rather than the more active, above-ground lifestyle of Ptychadena. In addition, based upon analysis of available mitochondrial DNA data, we have identified major clades within the genus Ptychadena and propose them as four species groups, with the P. mascareniensis group being the first diverging lineage (∼20 Mya). We also report four new localities of Lanzarana largeni from central Somaliland, south-western Puntland, southern Somalia and south-eastern Ethiopia, extending the presently known range of the species westward. This represents the first official record of L. largeni from Ethiopia. An ecological niche model of L. largeni for present climatic conditions identifies extensive climatically highly suitable areas in central Somalia and south-eastern Ethiopia. A model for future climatic conditions estimates a substantial extension of climatically suitable areas to northern Somalia and north-eastern Kenya, likely due to predicted more humid conditions accompanying the increase of temperatures in the western Indian Ocean.

Species diversity in Pseudocercospora.

Species of Pseudocercospora are commonly associated with leaf and fruit spots on diverse plant hosts in sub-tropical and tropical regions. Pseudocercospora spp. have mycosphaerella-like sexual morphs, but represent a distinct genus in Mycosphaerellaceae (Mycosphaerellales, Dothideomycetes). The present study adds a further 29 novel species of Pseudocercospora from 413 host species representing 297 host genera occurring in 60 countries and designates four epitypes and one lectotype for established names. This study recognises 329 species names, with an additional 69 phylogenetic lineages remaining unnamed due to difficulty in being able to unambiguously apply existing names to those lineages. To help elucidate the taxonomy of these species, a phylogenetic tree was generated from multi-locus DNA sequence data of the internal transcribed spacers and intervening 5.8S nuclear nrRNA gene (ITS), partial actin (actA), and partial translation elongation factor 1-alpha (tef1), as well as the partial DNA-directed RNA polymerase II second largest subunit (rpb2) gene sequences. Novel species described in this study include those from various countries as follows: Australia, Ps. acaciicola from leaf spots on Acacia sp., Ps. anopter from leaf spots on Anopterus glandulosus, Ps. asplenii from leaf spots on Asplenium dimorphum, Ps. australiensis from leaf spots on Eucalyptus gunnii, Ps. badjensis from leaf spots on Eucalyptus badjensis, Ps. erythrophloeicola from leaf spots on Erythrophleum chlorostachys, Ps. grevilleae from leaf spots on Grevillea sp., Ps. lophostemonigena from leaf spots on Lophostemon confertus, Ps. lophostemonis from leaf spots on Lophostemon lactifluus, Ps. paramacadamiae from leaf spots on Macadamia integrifolia, Ps. persooniae from leaf spots on Persoonia sp., Ps. pultenaeae from leaf spots on Pultenaea daphnoides, Ps. tristaniopsidis from leaf spots on Tristaniopsis collina, Ps. victoriae from leaf spots on Eucalyptus globoidea. Brazil, Ps. musigena from leaf spots on Musa sp. China, Ps. lonicerae-japonicae from leaf spots on Lonicera japonica, Ps. rubigena leaf spots on Rubus sp. France (Réunion), Ps. wingfieldii from leaf spots on Acacia heterophylla. Malaysia, Ps. musarum from leaf spots on Musa sp. Netherlands, Ps. rhododendri from leaf spots on Rhododendron sp. South Africa, Ps. balanitis from leaf spots on Balanites sp., Ps. dovyalidicola from leaf spots on Dovyalis zeyheri, Ps. encephalarticola from leaf spots on Encephalartos sp. South Korea, Ps. grewiana from leaf spots on Grewia biloba, Ps. parakaki from leaf spots on Diospyros kaki, Ps. pseudocydoniae from leaf spots on Chaenomeles lagenaria, Ps. paracydoniae from leaf spots on Chaenomeles speciosa. Thailand, Ps. acerigena from leaf spots on Acer sp., Ps. tectonigena from leaf spots on Tectona grandis. Epitypes are designated for Cercospora bonjeaneae-rectae, Cercospora halleriae, Ps. eucleae, and an epitype as well as a lectotype for Ps. macadamiae. Results obtained in the present study contribute to a better understanding of the host specificity and distribution in Pseudocercospora spp., many of which represent important pathogens of food or fibre crops, or organisms of quarantine concern. Citation: Groenewald JZ, Chen YY, Zhang Y, Roux J, Shin H-D, Shivas RG, Summerell BA, Braun U, Alfenas AC, Ujat AH, Nakashima C, Crous PW (2024). Species diversity in Pseudocercospora. Fungal Systematics and Evolution 13: 29-89. doi: 10.3114/fuse.2024.13.03.

Fungal Species Causing Canker and Wilt of Ficus carica and Evidence of Their Association by Bark Beetles in Italy.

Field surveys conducted during 2021 and 2022 in Western Sicily, Italy, revealed the presence of common fig trees severely affected by trunk and crown root canker and bark cracking. Moreover, in conjunction with the symptomatic tissues, the same surveyed plants showed the presence of bark beetle holes and internal wood galleries. The predominant beetle Criphalus dilutus was previously reported attacking figs in Sicily. Phylogenetic analyses based on multilocus DNA data showed the presence of different fungal taxa associated with disease symptoms, including Botryosphaeria dothidea, Ceratocystis ficicola, Diaporthe foeniculina, Neocosmospora bostrycoides, N. perseae, and Neofusicoccum luteum. Pathogenicity tests conducted on potted fig plants showed that all the species were pathogenic to fig, with C. ficicola and Neocosmospora spp. as the most aggressive fungal species. Moreover, isolations conducted from the bodies of emerging adult insects recovered from disease samples confirmed the presence of C. ficicola and Neocosmospora spp., suggesting the potential involvement of C. dilutus in their dissemination.

Diversity of mycoparasitic Pythium sensu stricto and Globisporangium species in West Azarbaijan province of Iran

AbstractPythium sensu stricto (s.s.) and Globisporangium species are important components of the soil microbial community and exhibit diverse lifestyles, including mycoparasitism. However, a comprehensive understanding of the species diversity of these mycoparasites in the West Azarbaijan province of Iran is lacking. In this study, a total of 114 mycoparasitic Pythium s.s. and Globisporangium isolates were obtained from agricultural soils collected from six regions in the province. Through DNA barcoding, all Globisporangium isolates were identified as G. nunn, while the barcode markers were insufficient to accurately resolve species boundaries in Pythium s.s. By combining morphological and multilocus sequence data, five species within the genus Pythium s.s. were identified: P. salmasense sp. nov., a potentially new species, and three known species, P. acanthicum, P. ornamentatum, and P. periplocum. Pythium ornamentatum was the most common species and found in all regions studied, followed by G. nunn and P. acanthicum, which were both isolated from four regions. While the isolates of G. nunn showed no mycoparasitic activity against Sclerotinia sclerotiorum, all Pythium s.s. species were capable of infecting the hyphae of this pathogen. The existence of mycoparasitic species is promising for biological control of soil‐borne fungal pathogens in the province. The widespread occurrence of P. ornamentatum, G. nunn, and P. acanthicum may suggest their adaptation to local soil and environmental conditions, indicating their potentially superior effectiveness in controlling plant diseases across different regions if used as biocontrol agents.

Rectifying a century of misidentifications: a taxonomic re-evaluation of sipo snakes (Colubridae: Chironius) on Trinidad

The island of Trinidad has several endemic reptile species that in some cases are morphologically indistinguishable, or almost so, from their mainland counterparts. In particular, many snakes from the island have not been examined thoroughly with modern scientific methods and may therefore be misidentified. At least two species of sipo snakes (Chironius carinatus, C. septentrionalis) are reported to inhabit Trinidad, both being considered species already inhabiting the mainland, though their identities are based solely on morphology. Here, we evaluate the molecular distinctiveness of these Trinidadian snakes and assess their relationships to other members of the genus. We constructed a multi-locus data set (12S rRNA, 16S rRNA, cyt b, ND4, cmos, NT3, Rag-1, Rag-2) including novel sequences and those available on GenBank to perform Bayesian and maximum likelihood phylogenetic analyses. Our phylogenetic reconstruction elucidates the identity of both Trinidad species, which have been misidentified since their discovery, and we provide a literature review of their taxonomic history. More specifically, our results suggest that the Trinidad population of Chironius carinatus is an undescribed species, that we describe herein as Chironius nigelnoriegai sp. nov., and is the sister to C. flavopictus. Our results also demonstrate that the Trinidad population previously identified as C. septentrionalis is instead the mainland species C. cochranae, a member of a clade with C. foveatus, C. laurenti, and C. multiventris. Finally, we generated a time tree and inferred that our new species separated from C. flavopictus approximately 4 million years ago in the Pliocene, a time when the island of Trinidad detached from Northern Venezuela. This work contributes to a better understanding of species diversity of Trinidad and we hope that it assists in conservation efforts towards this important endemic region. These findings support the prospect of rapid speciation on Trinidad and implies that more extensive surveys of island squamates will reveal additional cryptic diversity. http://zoobank.org/urn:lsid:zoobank.org:pub:500DB91B-62CD-4051-9831-0BEEAC64C8E2

UCE-derived mitochondrial phylogeny reveals pervasive mito-nuclear discordances in serotine bats (genus Eptesicus) and complex evolutionary history in Eptesicus (Histiotus)

Studies of evolution and biodiversity require solid understanding of species systematics revealed by molecular phylogeny using multilocus genomic data. Multilocus analyses, nevertheless, remain difficult in non-model taxa due to limited access to samples and molecular resources. To help overcome this limitation, ultra-conserved elements (UCEs) have been developed to generate large nuclear datasets and build more robust species phylogenies. Recently, MitoFinder pipeline was developed to further extract mitochondrial genes from the off-target sequences in UCE libraries to allow mito-nuclear comparison and increase the mitochondrial genomic database. Here we applied MitoFinder to published UCE datasets of serotine bats (genus Eptesicus) and focused on E. (Histiotus) whose evolutionary history is poorly understood. Our results showed extensive mito-nuclear discordances in the divergence of major clades in Eptesicus and within E. (Histiotus), indicating potential incomplete lineage sorting and historical mitochondrial introgression within and across subgenera. Moreover, we collected several new samples of E. (Histiotus), including the first molecular data of the recently described E. (H) diaphanopterus, and combined available published sequences to generate the most taxa-complete mitochondrial phylogeny of E. (Histiotus) bats. Results supported the early divergence of E. (H.) magellanicus and the species status of E. (H.) diaphanopterus. In addition, we found strong evidence of cryptic diversity, with potentially new taxa in Peru, Uruguay, and Brazil, which needs to be evaluated in future studies using complementary data. Our study enriched the sequence database of serotine bats and shed light on the hidden diversity and complex evolutionary history of E. (Histiotus).

Environmentally associated colour divergence does not coincide with population structure across Lesser Antillean anoles

Abstract Species distributed across heterogeneous environments may undergo local adaptation, which can be limited by the homogenizing effects of gene flow. Lesser Antillean anoles exhibit dorsal colour variation associated with dramatic shifts in environment across small spatial scales, providing an excellent system for studying the maintenance of local adaptation despite ongoing gene flow. The 1995 Soufriere Hills eruption on Montserrat provides an opportunity to understand how natural disasters may influence the evolution of insular species. Thus, our study had two main objectives. First, we collected genetic, phenotypic, and environmental data to investigate whether environmentally associated dorsal coloration reflects underlying population structure in three species of Lesser Antillean anoles. Second, we examined the short-term evolutionary consequences of volcanism by comparing pre- and posteruption samples of Anolis lividus using multilocus sequence data. We found all three species exhibited genetic isolation-by-distance but not isolation-by-environment. Furthermore, phenotypic differences within each species were not predicted by genetic distances, suggesting gene flow across colour morphs. We confirmed the repopulation of A. lividus in the impacted area and found genetic diversity equivalent to pre-eruption sampling. Our findings contribute to our understanding of local adaptation in spatially small-scale systems and the impact of catastrophic natural disasters on population structure.

Taxonomy and phylogeny of the family Suberitidae (Porifera: Demospongiae) in California

This study presents a comprehensive taxonomic revision of the family Suberitidae (Porifera: Demospongiae) for California, USA. We include the three species previously known from the region, document two additional species previously known from other regions, and formally describe four new species as Pseudosuberites latke sp. nov., Suberites californiana sp. nov., Suberites kumeyaay sp. nov., and Suberites agaricus sp. nov. Multi-locus DNA sequence data is presented for seven of the nine species, and was combined with all publicly available data to produce the most comprehensive global phylogeny for the family to date. By integrating morphological and genetic data, we show that morphological characters may be sufficient for regional species identification but are likely inadequate for global classification into genera that reflect the evolutionary history of the family. We therefore propose that DNA sequencing is a critical component to support future taxonomic revisions.

Characterization of Colletotrichum species obtained from citrus in northern Thailand and introducing a new host record for C. plurivorum

AbstractCitrus trees are affected by many plant‐pathogenic fungi. The present study aimed to characterize Colletotrichum species on citrus showing anthracnose symptoms, leaf and fruit spot and wither tip in northern Thailand using multilocus data and assay their pathogenicity. The surveys were carried out from December 2021 to January 2022 and 73 isolates were obtained from infected tissues. The fungal strains were identified based on morphological traits and were confirmed via amplification and sequencing of ITS, ACT, CHS‐1, GAPDH and TUB2. In all, 41 isolates were subjected to multilocus phylogeny. Forty of these isolates of Colletotrichum species belonged to the C. gloeosporioides species complex and one isolate belonged to the C. orchidearum species complex. Colletotrichum siamense, comprising 19 isolates, was the most dominant species associated with symptomatic citrus, followed by C. gloeosporioides (17 isolates), C. fructicola (three isolates), C. endophytica (one isolate) and C. plurivorum (one isolate). C. plurivorum is reported for the first time from citrus in the world. These isolates were obtained from mandarin (Citrus reticulata), pomelo (C. maxima), Persian lime (C. latifolia), Thai lime (C. hystrix) and acid lime (C. aurantifolia). The pathogenicity of the isolated fungi was tested through inoculation on branch, fruit and leaf using the detached method on mandarin, pomelo and Persian lime hosts, confirming Koch's postulate. In terms of disease severity, C. gloeosporioides and C. siamense were observed to be the most pathogenic species. This is the first pathogenic and molecular study of Colletotrichum species infecting citrus in northern Thailand.

Ngāokeoke Aotearoa: The Peripatoides Onychophora of New Zealand.

(1) Background: Originally described as a single taxon, Peripatoides novaezealandiae (Hutton, 1876) are distributed across both main islands of New Zealand; the existence of multiple distinct lineages of live-bearing Onychophora across this spatial range has gradually emerged. Morphological conservatism obscured the true endemic diversity, and the inclusion of molecular tools has been instrumental in revealing these cryptic taxa. (2) Methods: Here, we review the diversity of the ovoviviparous Onychophora of New Zealand through a re-analysis of allozyme genotype data, mitochondrial DNA cytochrome oxidase subunit I sequences, geographic information and morphology. (3) Results: New analysis of the multilocus biallelic nuclear data using methods that do not require a priori assumptions of population assignment support at least six lineages of ovoviviparous Peripatoides in northern New Zealand, and mtDNA sequence variation is consistent with these divisions. Expansion of mitochondrial DNA sequence data, including representation of all existing taxa and additional populations extends our knowledge of the scale of sympatry among taxa and shows that three other lineages from southern South Island can be added to the Peripatoides list, and names are proposed here. In total, 10 species of Peripatoides can be recognised with current data.

PyPop: a mature open-source software pipeline for population genomics.

Python for Population Genomics (PyPop) is a software package that processes genotype and allele data and performs large-scale population genetic analyses on highly polymorphic multi-locus genotype data. In particular, PyPop tests data conformity to Hardy-Weinberg equilibrium expectations, performs Ewens-Watterson tests for selection, estimates haplotype frequencies, measures linkage disequilibrium, and tests significance. Standardized means of performing these tests is key for contemporary studies of evolutionary biology and population genetics, and these tests are central to genetic studies of disease association as well. Here, we present PyPop 1.0.0, a new major release of the package, which implements new features using the more robust infrastructure of GitHub, and is distributed via the industry-standard Python Package Index. New features include implementation of the asymmetric linkage disequilibrium measures and, of particular interest to the immunogenetics research communities, support for modern nomenclature, including colon-delimited allele names, and improvements to meta-analysis features for aggregating outputs for multiple populations. Code available at: https://zenodo.org/records/10080668 and https://github.com/alexlancaster/pypop.

A revised phylogeny of Boletaceae using whole genome sequences

ABSTRACT The porcini mushroom family Boletaceae is a diverse, widespread group of ectomycorrhizal (ECM) mushroom-forming fungi that so far has eluded intrafamilial phylogenetic resolution based on morphology and multilocus data sets. In this study, we present a genome-wide molecular data set of 1764 single-copy gene families from a global sampling of 418 Boletaceae specimens. The resulting phylogenetic analysis has strong statistical support for most branches of the tree, including the first statistically robust backbone. The enigmatic Phylloboletellus chloephorus from non-ECM Argentinian subtropical forests was recovered as a new subfamily sister to the core Boletaceae. Time-calibrated branch lengths estimate that the family first arose in the early to mid-Cretaceous and underwent a rapid radiation in the Eocene, possibly when the ECM nutritional mode arose with the emergence and diversification of ECM angiosperms. Biogeographic reconstructions reveal a complex history of vicariance and episodic long-distance dispersal correlated with historical geologic events, including Gondwanan origins and inferred vicariance associated with its disarticulation. Together, this study represents the most comprehensively sampled, data-rich molecular phylogeny of the Boletaceae to date, establishing a foundation for future robust inferences of biogeography in the group.

High diversity within and low but significant genetic differentiation among geographic and temporal populations of the global Streptococcus pneumoniae.

Streptococcus pneumoniae is the major cause of invasive pneumococcal disease. However, the global population structure remains largely unexplored. In this study, we investigated the spatial and temporal patterns of genetic variation of S. pneumoniae based on archived multilocus sequence typing data from PubMLST.org. Our analyses demonstrated both shared and unique distributions of sequence types (STs) and allele types among regional populations. Among the 17 915 global STs, 36 representing 15 263 isolates were broadly shared among all six continents, consistent with recent clonal dispersal and expansion of this pathogen. The analysis of molecular variance revealed that>96% genetic variations were found within individual regional populations. However, though low (<4%), statistically significant genetic differentiation among regional populations was observed. Comparisons between non-clone-corrected and clone-corrected datasets showed that localized clonal expansion contributed significantly to the observed genetic differentiations among regions. Temporal analyses of the isolates showed that implementation of pneumococcal conjugate vaccine impacted the distributions of STs, but the effect on population structure was relatively limited. Linkage disequilibrium analyses identified evidence for recombination in all continental populations; however, the inferred recombination was not random. We discussed the limitations and implications of our analyses to the global epidemiology and future vaccine developments for S. pneumoniae.

Bursts of coalescence within population pedigrees whenever big families occur.

We consider a simple diploid population-genetic model with potentially high variability of offspring numbers among individuals. Specifically, against a backdrop of Wright-Fisher reproduction and no selection, there is an additional probability that a big family occurs, meaning that a pair of individuals has a number of offspring on the order of the population size. We study how the pedigree of the population generated under this model affects the ancestral genetic process of a sample of size two at a single autosomal locus without recombination. Our population model is of the type for which multiple-merger coalescent processes have been described. We prove that the conditional distribution of the pairwise coalescence time given the random pedigree converges to a limit law as the population size tends to infinity. This limit law may or may not be the usual exponential distribution of the Kingman coalescent, depending on the frequency of big families. But because it includes the number and times of big families, it differs from the usual multiple-merger coalescent models. The usual multiple-merger coalescent models are seen as describing the ancestral process marginal to, or averaging over, the pedigree. In the limiting ancestral process conditional on the pedigree, the intervals between big families can be modeled using the Kingman coalescent but each big family causes a discrete jump in the probability of coalescence. Analogous results should hold for larger samples and other population models. We illustrate these results with simulations and additional analysis, highlighting their implications for inference and understanding of multilocus data.

Fasta2Structure: a user-friendly tool for converting multiple aligned FASTA files to STRUCTURE format

BackgroundThe STRUCTURE software has gained popularity as a tool for population structure and genetic analysis. Nevertheless, formatting data to meet STRUCTURE's specific requirements can be daunting and susceptible to errors, especially when handling multilocus data. This article highlights the creation of a graphical user interface (GUI) application tailored to streamline the process of converting multiple sequence alignments into a single, cohesive file that is compatible with the STRUCTURE software.ResultsThe application has been developed utilizing Tkinter for the GUI and Biopython for handling FASTA files. This program processes the files, pinpoints variable sites, and converts the sequences into a binary format. Subsequently, the sequences are concatenated and presented within the graphical interface's text area, enabling users to review and confirm the results. Furthermore, the program stores the concatenated results in a file, delivering a ready-to-use input for the STRUCTURE software.ConclusionThis application offers an efficient and dependable solution for transforming multiple aligned FASTA files into a concatenated binary format file, which is compatible with the STRUCTURE software. With its user-friendly graphical interface and error-reduction approach, this tool proves invaluable for researchers engaged in population structure and genetic analysis.