scholarly journals Phylogenomic analyses support traditional relationships within Cnidaria

2015 ◽  
Author(s):  
Felipe Zapata ◽  
Freya E Goetz ◽  
Stephen A Smith ◽  
Mark Howison ◽  
Stefan Siebert ◽  
...  

Cnidaria, the sister group to Bilateria, is a highly diverse group of animals in terms of morphology, lifecycles, ecology, and development. How this diversity originated and evolved is not well understood because phylogenetic relationships among major cnidarian lineages are unclear, and recent studies present contrasting phylogenetic hypotheses. Here, we use transcriptome data from 15 newly-sequenced species in combination with 26 publicly available genomes and transcriptomes to assess phylogenetic relationships among major cnidarian lineages. Phylogenetic analyses using different partition schemes and models of molecular evolution, as well as topology tests for alternative phylogenetic relationships, support the monophyly of Medusozoa, Anthozoa, Octocorallia, Hydrozoa, and a clade consisting of Staurozoa, Cubozoa, and Scyphozoa. Support for the monophyly of Hexacorallia is weak due to the equivocal position of Ceriantharia. Taken together, these results further resolve deep cnidarian relationships, largely support traditional phylogenetic views on relationships, and provide a historical framework for studying the evolutionary processes involved in one of the most ancient animal radiations.

2015 ◽  
Vol 28 (4) ◽  
pp. 203 ◽  
Author(s):  
Xénia A. Weber ◽  
Alexander N. Schmidt-Lebuhn

The Australasian clade of Gnaphalieae (Asteraceae) is an ecologically diverse group of species whose generic limits and phylogenetic relationships are still partly unresolved. Previous studies including hybridisation trials, morphological characterisation and preliminary phylogenetic analyses within the Gnaphalieae have suggested that two genera, namely, Waitzia and Leucochrysum, require further investigation into their generic boundaries. To explore the phylogenetic relationships of both genera, the present study used a combination of morphological and molecular approaches. The character traits of herbarium specimens from 14 species and six infraspecific taxa of Waitzia, Leucochrysum and Anemocarpa were examined. Chloroplast (psbA–trnH) and nuclear ribosomal ITS and ETS sequences were generated for phylogenetic analysis. Our findings support Waitzia in its current circumscription as a monophyletic group, whereas Leucochrysum was found to be polyphyletic. Leucochrysum fitzgibbonii was found to be the sister group of Waitzia and shares characters of the involucral bracts, indumentum and growth habit with that genus. The species is formally transferred to the genus Waitzia as W. fitzgibbonii.


2014 ◽  
Vol 281 (1794) ◽  
pp. 20141739 ◽  
Author(s):  
Felipe Zapata ◽  
Nerida G. Wilson ◽  
Mark Howison ◽  
Sónia C. S. Andrade ◽  
Katharina M. Jörger ◽  
...  

Gastropods are a highly diverse clade of molluscs that includes many familiar animals, such as limpets, snails, slugs and sea slugs. It is one of the most abundant groups of animals in the sea and the only molluscan lineage that has successfully colonized land. Yet the relationships among and within its constituent clades have remained in flux for over a century of morphological, anatomical and molecular study. Here, we re-evaluate gastropod phylogenetic relationships by collecting new transcriptome data for 40 species and analysing them in combination with publicly available genomes and transcriptomes. Our datasets include all five main gastropod clades: Patellogastropoda, Vetigastropoda, Neritimorpha, Caenogastropoda and Heterobranchia. We use two different methods to assign orthology, subsample each of these matrices into three increasingly dense subsets, and analyse all six of these supermatrices with two different models of molecular evolution. All 12 analyses yield the same unrooted network connecting the five major gastropod lineages. This reduces deep gastropod phylogeny to three alternative rooting hypotheses. These results reject the prevalent hypothesis of gastropod phylogeny, Orthogastropoda. Our dated tree is congruent with a possible end-Permian recovery of some gastropod clades, namely Caenogastropoda and some Heterobranchia subclades.


2014 ◽  
Author(s):  
Felipe Zapata ◽  
Nerida G. Wilson ◽  
Mark Howison ◽  
Sónia CS Andrade ◽  
Katharina M. Jörger ◽  
...  

Gastropods are a highly diverse clade of molluscs that includes many familiar animals, such as limpets, snails, slugs, and sea slugs. It is one of the most abundant groups of animals in the sea and the only molluscan lineage that has successfully colonised land. Yet the relationships among and within its constituent clades have remained in flux for over a century of morphological, anatomical and molecular study. Here we re-evaluate gastropod phylogenetic relationships by collecting new transcriptome data for 40 species and analysing them in combination with publicly available genomes and transcriptomes. Our datasets include all five main gastropod clades: Patellogastropoda, Vetigastropoda, Neritimorpha, Caenogastropoda and Heterobranchia. We use two different methods to assign orthology, subsample each of these matrices into three increasingly dense subsets, and analyse all six of these supermatrices with two different models of molecular evolution. All twelve analyses yield the same unrooted network connecting the five major gastropod lineages. This reduces deep gastropod phylogeny to three alternative rooting hypotheses. These results reject the prevalent hypothesis of gastropod phylogeny, Orthogastropoda. Our dated tree is congruent with a possible end-Permian recovery of some gastropod clades, namely Caenogastropoda and some Heterobranchia subclades.


2017 ◽  
Author(s):  
Guifre Torruella ◽  
Xavier Grau-Bove ◽  
David Moreira ◽  
Sergey A Karpov ◽  
John Burns ◽  
...  

Aphelids are poorly known phagotrophic parasites of algae whose life cycle and morphology resemble those of the widely diverse parasitic rozellids (Cryptomycota, Rozellomycota). In previous phylogenetic analyses of RNA polymerase and rRNA genes, aphelids and rozellids formed a monophyletic group together with the extremely reduced parasitic Microsporidia, named Opisthosporidia, which was sister to Fungi. However, the statistical support for that group was always moderate. We generated the first transcriptome data for one aphelid species, Paraphelidium tribonemae. In-depth multi-gene phylogenomic analyses using various protein datasets place aphelids as the closest relatives of Fungi to the exclusion of rozellids and Microsporidia. In contrast with the comparatively reduced Rozella allomycis genome, we infer a rich, free-living-like aphelid proteome, including cellulases likely involved in algal cell-wall penetration, enzymes involved in chitin biosynthesis and several metabolic pathways. Our results suggest that Fungi evolved from a complex aphelid-like ancestor that lost phagotrophy and became osmotrophic.


2019 ◽  
Vol 19 (6) ◽  
Author(s):  
Wanqing Zhao ◽  
Qing Zhao ◽  
Min Li ◽  
Jiufeng Wei ◽  
Xianhong Zhang ◽  
...  

Abstract The family Pentatomidae, the largest within the superfamily Pentatomoidae, comprises about 5,000 species; many of which are economically important pests. Although the phylogeny of Pentatomidae species has been studied using various molecular markers, their phylogenetic relationships remain controversial. Recently, mitochondrial genomes (mitogenomes) have been extensively employed to examine the phylogenetics and evolution of different insects, and in this study, we sequenced complete/near-complete mitochondrial genomes from five shield bug species of Eurydema to gain a better understanding of phylogenetic relationships in the Pentatomidae. The five mitogenomes ranged in length from 15,500 to 16,752 bp and comprised 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a control region. We compared mitogenomic characteristics of the Pentatomidae and constructed phylogenetic trees using Bayesian inference and maximum likelihood methods. Our results showed that gene arrangements, base composition, start/stop codons, gene overlaps, and RNA structures were conserved within the Pentatomidae and that congeneric species shared more characteristics. Saturation and heterogeneity analyses revealed that our PCGs and PCGRNA datasets were valid for phylogenetic analysis. Phylogenetic analyses showed consistent topologies based on BI and ML methods. These analyses strongly supported that Eurydema species belong to the tribe Strachiini, and formed a sister group with Pentatomini. The relationships among Eurydema species were shown to be consistent with their morphological features. (Strachiini + Pentatomini) was found to be a stable sibling of the clade comprising Cappaeini, Graphosomini, and Carpocorini. Furthermore, our results indicated that Graphosoma rubrolineatum (Heteroptera: Pentatomidae) belongs to the Pentatominae and not the Podopinae.


2017 ◽  
Vol 91 (4) ◽  
pp. 829-846 ◽  
Author(s):  
David F. Wright ◽  
William I. Ausich ◽  
Selina R. Cole ◽  
Mark E. Peter ◽  
Elizabeth C. Rhenberg

AbstractA major goal of biological classification is to provide a system that conveys phylogenetic relationships while facilitating lucid communication among researchers. Phylogenetic taxonomy is a useful framework for defining clades and delineating their taxonomic content according to well-supported phylogenetic hypotheses. The Crinoidea (Echinodermata) is one of the five major clades of living echinoderms and has a rich fossil record spanning nearly a half billion years. Using principles of phylogenetic taxonomy and recent phylogenetic analyses, we provide the first phylogeny-based definition for the Clade Crinoidea and its constituent subclades. A series of stem- and node-based definitions are provided for all major taxa traditionally recognized within the Crinoidea, including the Camerata, Disparida, Hybocrinida, Cladida, Flexibilia, and Articulata. Following recommendations proposed in recent revisions, we recognize several new clades, including the Eucamerata Cole 2017, Porocrinoidea Wright 2017, and Eucladida Wright 2017. In addition, recent phylogenetic analyses support the resurrection of two names previously abandoned in the crinoid taxonomic literature: the Pentacrinoidea Jaekel, 1918 and Inadunata Wachsmuth and Springer, 1885. Last, a phylogenetic perspective is used to inform a comprehensive revision of the traditional rank-based classification. Although an attempt was made to minimize changes to the rank-based system, numerous changes were necessary in some cases to achieve monophyly. These phylogeny-based classifications provide a useful template for paleontologists, biologists, and non-experts alike to better explore evolutionary patterns and processes with fossil and living crinoids.


2011 ◽  
Vol 143 (6) ◽  
pp. 662-673 ◽  
Author(s):  
Marc Pollet ◽  
Christoph Germann ◽  
Marco Valerio Bernasconi

AbstractMedetera Fischer von Waldheim is the most speciose genus in the Medeterinae, with a nearly ubiquitous global distribution. Phylogenetic relationships within Medetera and between Medetera and four other medeterine genera were investigated using mitochondrial (COI, 16S) and nuclear (18S) markers to test morphological hypotheses. Our results confirm most of Bickel's hypotheses. Thrypticus Gerstäcker shows a sister-group relationship with Medetera + Dolichophorus Lichtwardt. The Medetera species included here split into two clades. One clade corresponds to the M. diadema L. – veles Loew species group sensu Bickel. The second clade is largely composed of the M. apicalis (Zetterstedt) species group sensu Bickel and the M. aberrans Wheeler species group sensu Bickel + Dolichophorus. Although most Medeterinae are associated with plants (mainly trees), species in at least two separate lineages demonstrate a secondary return to terrestrial habitats. The implication of this evolutionary phenomenon is briefly discussed.


1996 ◽  
Vol 351 (1345) ◽  
pp. 1241-1249 ◽  

Phylogenetic comparative analyses combine information on character states and phylogenetic relationships of taxa to test hypotheses regarding character evolution. These studies encounter uncertainties at various steps, including uncertainty in the topology of phylogenetic trees, the scoring of characters, and the addition of taxa that have not explicitly been included in phylogenetic analyses. Here we highlight a variety of sensitivity tests designed to explore the robustness of comparative conclusions to changes in underlying assumptions. These include the examination of character correlations on a set of plausible phylogenetic hypotheses (including alternative rootings and ‘neighbouring’ trees), as well as under alternative character codings. TreeBASE -a prototype relational database of phylogenetic data - should prove useful in accessing alternative hypotheses.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12104
Author(s):  
Bastian Bentlage ◽  
Allen G. Collins

Higher-level relationships of the Hydrozoan subclass Hydroidolina, which encompasses the vast majority of medusozoan cnidarian species diversity, have been elusive to confidently infer. The most widely adopted phylogenetic framework for Hydroidolina based on ribosomal RNA data received low support for several higher level relationships. To address this issue, we developed a set of RNA baits to target more than a hundred loci from the genomes of a broad taxonomic sample of Hydroidolina for high-throughput sequencing. Using these data, we inferred the relationships of Hydroidolina using maximum likelihood and Bayesian approaches. Both inference methods yielded well-supported phylogenetic hypotheses that largely agree with each other. Using maximum likelihood and Baysian hypothesis testing frameworks, we found that several alternate topological hypotheses proposed previously may be rejected in light of the genomic data generated for this study. Both the maximum likelihood and Bayesian topologies inferred herein consistently score well across testing frameworks, suggesting that their consensus represents the most likely phylogenetic hypothesis of Hydroidolina. This phylogenetic framework places Aplanulata as sister lineage to the remainder of Hydroidolina. This is a strong deviation from previous phylogenetic analyses that placed Capitata or Siphonophorae as sister group to the remainder of Hydroidolina. Considering that Aplanulata represents a lineage comprised of species that for the most part possess a life cycle involving a solitary polyp and free-swimming medusa stage, the phylogenetic hypotheses presented herein have potentially large implications for clarifying the evolution of life cycles, coloniality, and the division of labor in Hydrozoa as taxon sampling for phylogenetic analyses becomes more complete.


2000 ◽  
Vol 77 (12) ◽  
pp. 1756-1768 ◽  
Author(s):  
Kadri Põldmaa ◽  
Ellen Larsson ◽  
Urmas Kõljalg

To infer phylogenetic relationships among species of Hypomyces (Fr.) Tul and allied genera, partial sequences of the 28S rDNA were obtained for 21 strains representing 19 species. On the basis of these data and 38 sequences obtained from GenBank, phylogenetic analyses were performed using the programs PAUP and Pee-Wee. Hypomyces appears to be paraphyletic, with species having wet-conidial phialidic anamorphs more closely related to other genera. Hypomyces chrysostomus Berk & Broome is a sister group to the clade that includes species of Aphysiostroma Barrasa et al., Arachnocrea Moravec, and Hypocrea Fr. Based on morphological and molecular evidence, a new genus, Sporophagomyces, is described for Hypomyces chrysostomus and two allied species. Hypomyces broomeanus Tul. forms one clade with species of Sphaerostilbella Sacc. and is transferred to this genus. The recognition of Arachnocrea is justified. The integration of Cladobotryum Nees species that are not known to undergo sexual reproduction with Hypomyces species that possess Cladobotryum anamorphs receives strong support, but the whole complex of these species appears to be paraphyletic. However, constraint trees, which require monophyly of all these ana- and pleo-morphic species, do not appear significantly less likely than the other trees obtained under maximum likelihood or parsimony criteria. For the remaining species of Hypomyces, four distinct lineages are distinguished.


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