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Mol Phylogenet Evol [journal]
- Exploring New Dating Approaches for Parasites: The Worldwide Apodanthaceae (Cucurbitales) As an Example. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 21.
Gene trees of holoparasitic plants usually show distinctly longer branch lengths than seen in photosynthetic closest relatives. Such substitution rate jumps have made it difficult to infer the absolute divergence times of parasites. An additional problem is that parasite clades often lack a fossil record. Using nuclear and mitochondrial DNA sequences of Apodanthaceae, a worldwide family of endoparasites living inside Fabaceae and Salicaceae, we compared several new dating approaches: (i) an uncorrelated lognormal (UCLN) model calibrated with outgroup fossils, (ii) ages of host lineages as a maximal age in an UCLN model, (iii) user-assigned local clocks, and (iv) outgroup-fossil-calibrated random local clocks (RLC) with varying prior probabilities on the number of permitted rate changes (RLCu and RLCp models), a variable that has never been explored. The resulting dated phylogenies include all 10 species of the family, three in Australia, one in Iran, one in Africa, and the remainder in the Americas. All clock models infer a drastic rate jump between nonparasitic outgroups and Apodanthaceae, but since they distribute the rate heterogeneity differently, they result in much-different age estimates. Bayes factors using path and stepping-stone sampling indicated that the RLCp model fit poorly, while for matR topologically unconstrained RLCu and UCLN models did not differ significantly and for 18S, the UCLN model was preferred, Under the equally well fitting models, the Apodanthaceae appear to be a relatively old clade, with a stem age falling between 65 and 81 my, the divergence of Apodanthes from Pilostyles between 36 and 57 my ago, and the crown age of the Australian clade 8 to 18 my ago. In our study system, host-age calibrations did not yield well-constrained results, but they may work better in other parasite clades. For small data sets where statistical convergence can be reached even with complex models, random local clocks should be explored as an alternative to the exclusive reliance on UCLN clocks.
- Towards a phylogeny of the Tenebrionoidea (Coleoptera). [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jun 2.:305-312.
The phylogenetic relationships of the beetle superfamily Tenebrionoidea are investigated using the most comprehensive genetic data set compiled to date. With ∼34,000 described species in approximately 1250 genera and 28 families, Tenebrionoidea represent one of the most diverse and species-rich superfamilies of beetles. The interfamilial relationships of the Tenebrionoidea are poorly known; previous morphological and molecular phylogenies recovered few well-supported and often conflicting relationships between families. Here we present a molecular phylogeny of Tenebrionoidea based on genes commonly used to resolve family and superfamily-level phylogenies of beetles (18S, 28S, 16S, 12S, tRNA Val and COI). The alignment spanned over 6.5KB of DNA sequence and over 300 tenebrionoid genera from 24 of the 28 families were sampled. Maximum Likelihood and Bayesian analysis could not resolve deeper level divergences within the superfamily and very few relationships between families were supported. Increasing gene coverage in the alignment by removing taxa with missing data did not improve clade support but when rogue taxa were removed increased resolution was recovered. Investigation of signal strength suggested conflicting phylogenetic signal was present in the standard genes used for beetle phylogenetics, even when rogue taxa were removed. Our study of Tenebrionoidea highlights that even with relatively comprehensive taxon sampling within a lineage, this standard set of genes is unable to resolve relationships within this superfamily.
- Phylogeography of Cuban Rivulus: evidence for allopatric speciation and secondary dispersal across a marine barrier. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 19.
The genus Rivulus is currently comprised of two species, R. cylindraceus and R. insulaepinorum, which are endemic to Cuba. However, the taxonomic status of the latter species remains dubious because of the poor quality of the original description. In addition, a recent barcoding survey suggests that the two species may be conspecific. The aim of this study was to test the hypothesis that the two species represent a single evolutionary clade. To delimit the species and their evolutionary history, we used a combination of molecular phylogenetic analyses, with both mitochondrial and nuclear sequences, tests of phylogeographic hypotheses, combined with morphological measurements and information on known dispersal barriers and species distribution. None of the data sets support R. insulaepinorum and R. cylindraceus as separate taxa. However, a new species, restricted to the northwestern part of the main island, was identified by phylogenetic analyses, body colour pattern and geographical distribution. The evolutionary distance between the two lineages (cytb, d = 15%; CAM-4, d = 2.5%) indicates a long period of divergence. Phylogeographic analyses shed light on the dispersal history of R. cylindraceus, which probably originated on the Isla de la Juventud. They also suggest that each lineage had contrasting histories; Rivulus sp. is restricted to a relatively small geographic area whereas R. cylindraceus has dispersed considerably and more than once from its centre of origin, probably facilitated by sea level fluctuations. These results strengthen previous findings, i.e. that the diversity of Cuban freshwater fishes is far from well-known and deserves more in-depth studies, and that vicariance and dispersal events have resulted in a complex biogeographical landscape which has had a significant impact on the freshwater fishes of the Caribbean islands.
- The shared mitochondrial genome of Rupicapra pyrenaica ornata and Rupicapra rupicapra cartusiana: Old remains of a common past. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 15.
Mitochondrial DNA (mtDNA) has largely been used for species delimitation. However, mtDNA introgression across species boundaries can lead to inconsistent phylogenies. Partial sequences of the mitochondrial genome in the chamois, genus Rupicapra, show the presence of three well differentiated clades, West (mtW), Central (mtC) and East (mtE), each with a geographically restricted distribution. The complete mtDNAs of the clades mtW and mtE (main representatives of the two currently considered species R. pyrenaica and R. rupicapra respectively) have been reported. In the present study, we sequenced the clade mtC present in populations from both species inhabiting the central area of Europe: the Apennines (R. pyrenaica ornata) and the Chartreuse Mountains (R. rupicapra cartusiana). The phylogenetic comparison with the genomes of Caprini highlights the ancient presence of chamois in Europe relative to the fossil record, and the old age of the chamois clade mtC that was split from the clade mtW in the early Pleistocene. The separation of R. pyrenaica ornata and R. rupicapra cartusiana female lineages was recent, dating of the late Pleistocene. Our data represent an example of mtDNA introgression of resident females of Chartreuse Mountains into immigrant males of R. rupicapra due to male-biased migration and female phylopatry.
- Evolution of Bornaviruses. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 18.
Recently, Avian Bornavirus (ABV) was identified to be a new member of the Bornaviridae family consisting solely of the mammal-infecting Borna disease virus (BDV). Here, to gain more insights into the evolution of these bornaviruses, the time-stamped N gene sequences of BDV genotype 1 (BDV1) and ABV were subjected to Bayesian coalescent analyses. The nucleotide substitution rates and the divergence times were estimated. Age calculations suggested that the first diversification event of the analyzed BDV1 isolates might have taken place about 300 years ago, and revealed that ABV was an old virus newly recognized. Great differences were observed in the rate of nucleotide substitution and the pattern of codon usage bias between BDV1 and ABV. Moreover, the analyzed bornaviruses might be descended from an AT-rich ancestor.
- The corbiculate bees arose from New World oil-collecting bees: Implications for the origin of pollen baskets. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 15.
The economically most important group of bees is the "corbiculates", or pollen basket bees, some 890 species of honeybees (Apis), bumblebees (Bombus), stingless bees (Meliponini), and orchid bees (Euglossini). Molecular studies have indicated that the corbiculates are closest to the New World genera Centris, with 230 species, and Epicharis, with 35, albeit without resolving the precise relationships. Instead of concave baskets, these bees have hairy hind legs on which they transport pollen mixed with floral oil, collected with setae on the anterior and middle legs. We sampled two-thirds of all Epicharis, a third of all Centris, and representatives of the four lineages of corbiculates for four nuclear gene regions, obtaining a well-supported phylogeny that has the corbiculate bees nested inside the Centris/Epicharis clade. Fossil-calibrated molecular clocks, combined with a biogeographic reconstruction incorporating insights from the fossil record, indicate that the corbiculate clade arose in the New World and diverged from Centris 84 (72-95)mya. The ancestral state preceding corbiculae thus was a hairy hind leg, perhaps adapted for oil transport as in Epicharis and Centris bees. Its replacement by glabrous, concave baskets represents a key innovation, allowing efficient transport of plant resins and large pollen/nectar loads and freeing the corbiculate clade from dependence on oil-offering flowers. The transformation could have involved a novel function of Ubx, the gene known to change hairy into smooth pollen baskets in Apis and Bombus.
- Phylogeny and character evolution of the fern genus Tectaria (Tectariaceae) in the Old World inferred from chloroplast DNA sequences. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 14.
In this study we provide a phylogeny for the pantropical fern genus Tectaria, with emphasis on the Old World species, based on sequences of five plastid regions (atpB, ndhF plus ndhF-trnL, rbcL, rps16-matK plus matK, and trnL-F). Maximum parsimony, maximum likelihood, and Bayesian inference are used to analyze 115 individuals, representing ca. 56 species of Tectaria s.l. and 36 species of ten related genera. The results strongly support the monophyly of Tectaria in a broad sense, in which Ctenitopsis, Hemigramma, Heterogonium, Psomiocarpa, Quercifilix, Stenosemia, and Tectaridium should be submerged. Such broadly circumscribed Tectaria is supported by the arising pattern of veinlets and the base chromosome number (x=40). Four primary clades are well resolved within Tectaria, one from the Neotropic (T. trifoliata clade) and three from the Old World (T. subtriphylla clade, Ctenitopsis clade, and T. crenata clade). Tectaria crenata clade is the largest one including six subclades. Of the genera previously recognized as tectarioid ferns, Ctenitis, Lastreopsis, and Pleocnemia, are confirmed to be members in Dryopteridaceae; while Pteridrys and Triplophyllum are supported in Tectariaceae. To infer morphological evolution, 13 commonly used characters are optimized on the resulting phylogenetic trees and in result, are all homoplastic in Tectaria.
- Artemia biodiversity in Asia with the focus on the phylogeography of the introduced American species Artemia franciscana Kellogg 1906. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 11.
Asia harbors a diverse group of sexual and asexual Artemia species, including the invasive Artemia franciscana, which is native to the Americas. The phylogeny of Asian Artemia species and the phylogeography of the introduced A. franciscana from 81 sampling localities in Eurasia, Africa and America were elucidated using mitochondrial (COI) and nuclear DNA (ITS1) sequences. According to a COI phylogeny, 6 distinctive genetic groups were recognized, with a complex phylogeographic structure among Asian Artemia. A haplotype complex which includes parthenogenetic lineages is distributed in 39 inland geographical localities in Asia, illustrating a wide distribution with a narrow genetic structure on this continent. The invasive A. franciscana was discovered in 31 geographical localities along the southern and eastern coastal regions of Asia. Three sexual species (A. sinica, A. tibetiana and A. urmiana) have a restricted distribution in certain geographical localities in Asia. In contrast to COI phylogeny reconstruction, ITS1 sequences showed inconsistency with the COI tree, indicating incomplete lineage sorting which provided the low genetic divergence in the Asian clade. Asian A. franciscana showed higher haplotype diversity as compared to the source population from the Great Salt Lake (USA), which could be attributed to multiple introductions by mass dispersal in Asia via human activities. The invasive success of A. franciscana in Asia could lead to a long-term biodiversity disturbance of the autochthonous Artemia species on the continent.
- Nucleotide substitution analyses of the glaucophyte Cyanophora suggest an ancestrally lower mutation rate in plastid vs mitochondrial DNA for the Archaeplastida. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jul 11.
A lot is known about the evolution and architecture of plastid, mitochondrial, and nuclear genomes, but surprisingly little is known about their relative rates of mutation. Most available relative-rate data come from seed plants, which, with few exceptions, have a mitochondrial mutation rate that is lower than those of the plastid and nucleus. But new findings from diverse plastid-bearing lineages have shown that for some eukaryotes the mitochondrial mutation rate is an order of magnitude greater than those of the plastid and nucleus. Here, we explore for the first time relative rates of mutation within the Glaucophyta-one of three main lineages that make up the Archaeplastida (or Plantae sensu lato). Nucleotide substitution analyses from distinct isolates of the unicellular glaucophyte Cyanophora paradoxa reveal 4-5-fold lower rates of mutation in the plastid and nucleus than the mitochondrion, which is similar to the mutational pattern observed in red algae and haptophytes, but opposite to that of seed plants. These data, together with data from previous reports, suggest that for much of the known photosynthetic eukaryotic diversity, plastid DNA mutations occur less frequently than those in mitochondrial DNA.
- Molecular phylogeny of short-tailed opossums (Didelphidae: Monodelphis): Taxonomic implications and tests of evolutionary hypotheses. [JOURNAL ARTICLE]
- Mol Phylogenet Evol 2014 Jun 2.:199-214.
Short-tailed opossums (genus Monodelphis) represent one of the most speciose clades of New World marsupials, with 26 currently recognized species that collectively range from eastern Panama to northern Argentina. Here we present the first phylogenetic analyses of the genus based on dense taxonomic sampling and multiple genes. From most sampled species we obtained >4800bp of DNA sequence from one mitochondrial gene (CYTB), two autosomal exons (IRBP exon 1, BRCA1 exon 11), one autosomal intron (SLC38 intron 7), and one X-linked intron (OGT intron 14). Maximum-parsimony, maximum-likelihood and Bayesian analyses of these data strongly support the monophyly of Monodelphis and recover six major clades within the genus. Additionally, our analyses support previous suggestions that several nominal taxa are synonyms of other species (M. "sorex" of M. dimidiata, M. "theresa" of M. scalops, M. "rubida" and M. "umbristriata" of M. americana, and M. "maraxina" of M. glirina). By contrast, four unnamed lineages recovered by our analyses may represent new species. Reconstructions of ancestral states of two discrete characters-dorsal pelage color pattern and habitat-suggest that the most recent common ancestor of Monodelphis was uniformly colored (with unpatterned dorsal pelage) and inhabited moist forest. Whereas some dorsal pelage patterns appear to have evolved homoplastically in Monodelphis, dorsal stripes may have had a unique historical origin in this genus.