The most extensive combined phylogenetic analyses of the subclass Marchantiidae yet undertaken was conducted on the basis of morphological and molecular data. The morphological data comprised 126 characters and 56 species. Taxonomic sampling included 35 ingroup species with all genera and orders of Marchantiidae sampled, and 21 outgroup species with two genera of Blasiidae (Marchantiopsida), 15 species of Jungermanniopsida (the three subclasses represented) and the three genera of Haplomitriopsida. Takakia ceratophylla (Bryophyta) was employed to root the trees. Character sampling involved 92 gametophytic and 34 sporophytic traits, supplemented with ten continuous characters. Molecular data included 11 molecular markers: one nuclear ribosomal (26S), three mitochondrial genes (nad1, nad5, rps3) and seven chloroplast regions (atpB, psbT‐psbH, rbcL, ITS, rpoC1, rps4, psbA). Searches were performed under extended implied weighting, weighting the character blocks against the average homoplasy. Clade stability was assessed across three additional weighting schemes (implied weighting corrected for missing entries, standard implied weighting and equal weighting) in three datasets (molecular, morphological and combined). The contribution from different biological phases regarding node recovery and diagnosis was evaluated. Our results agree with many of the previous studies but cast doubt on some relationships, mainly at the family and interfamily level. The combined analyses underlined the fact that, by combining data, taxonomic enhancements could be achieved regarding taxon delimitation and quality of diagnosis. Support values for many clades of previous molecular studies were improved by the addition of morphological data. The long‐held assumption that morphology may render spurious or low‐quality results in this taxonomic group is challenged. The morphological trends previously proposed are re‐evaluated in light of the new phylogenetic scheme.
The eusporangiate marattialean ferns represent an ancient radiation with a rich fossil record but limited modern diversity in the tropics. The long evolutionary history without close extant relatives has confounded studies of the phylogenetic origin, rooting and timing of marattialean ferns. Here we present new complete plastid genomes of six marattialean species and compiled a plastid genome dataset representing all of the currently accepted marattialean genera. We further supplemented this dataset by compiling a large dataset of mitochondrial genes and a phenotypic data matrix covering both extant and extinct representatives of the lineage. Our phylogenomic and total-evidence analyses corroborated the postulated position of marattialean ferns as the sister to leptosporangiate ferns, and the position of Danaea as the sister to the remaining extant marattialean genera. However, our results provide new evidence that Christensenia is sister to Marattia and that M. cicutifolia actually belongs to Eupodium. The apparently highly reduced rate of molecular evolution in marattialean ferns provides a challenge for dating the key phylogenetic events with molecular clock approaches. We instead applied a parsimony-based total-evidence dating approach, which suggested a Triassic age for the extant crown group. The modern distribution can best be explained as mainly resulting from vicariance following the breakup of Pangaea and Gondwana. We resolved the fossil genera Marattiopsis, Danaeopsis and Qasimia as members of the monophyletic family Marattiaceae, and the Carboniferous genera Sydneia and Radstockia as the monophyletic sister of all other marattialean ferns.
In recent years, the use of extensive molecular and morphological datasets has clarified the phylogenetic relationships among the orders of complex thalloid liverworts (Marchantiidae). However, previous studies excluded extinct taxa; thereby, undersampling the actual taxonomic diversity of the group. Here, we conducted a total-evidence analysis of Marchantiidae incorporating fossils. The combined dataset consisted of 11 genes-sampled from the nuclear, mitochondrial and plastid genomes-and 128 morphological characters. Sixty-two species, representing all classes and orders within Marchantiophyta and genera within Marchantiidae were included in the analyses. Six fossils were scored from literature: two assigned to the outgroup (Metzgeriothallus sharonae and Pallaviciniites sandaolingensis) and four to the ingroup (Marchantites cyathodoides, M. huolinhensis, Ricciopsis ferganica and R. sandaolingensis). Tree searches were conducted using parsimony as the optimality criterion. Clade sensitivity was assessed across a wide range of weighting regimes. Also, we evaluated the influence of fossils on the inferred topologies and branch support. Our results were congruent with previously inferred clades above the order level: Neohodgsoniales was sister to a clade formed by Sphaerocarpales and Marchantiales. However, relationships among families within Marchantiales contradicted recent studies. For instance, a clade consisting of Monosoleniaceae, Wiesnerellaceae and Targioniaceae was sister to the morphologically simple taxa instead of being nested within them as in previous studies. Novel synapomorphies were found for several clades within Marchantiales. Outgroup fossils were more influential than Marchantiidae fossils on overall topologies and branch support values. Except for a single weighting scheme, sampling continuous characters and down-weighting characters improved fossil stability. Ultimately, our results challenge the widespread notion that bryophyte fossils are problematic for phylogenetic inference.
Aims The precise localization of manifest posteroseptal accessory pathways (APs) often poses diagnostic challenges considering that a small area may encompass AP that may be ablated from the right or left endocardium, or epicardially within the coronary sinus (CS). We sought to explore whether the QRS transition pattern in the precordial lead may help to discriminate the necessary ablation approach. Methods and results Consecutive patients who underwent a successful ablation of a single manifest AP over a 5-year period were included. Standard 12-lead electrocardiograms were reviewed. A total of 273 patients were identified. Mean age was 31 ± 15 years and 62% were male. Of the 110 identified posteroseptal AP, 64 were ablated from the right endocardium, 33 from the left endocardium, and 13 inside the CS. While a normal precordial QRS transition was most often observed, a subset of 33 patients presented an atypical ‘double transition’ pattern which specifically identified right endocardial AP. The combination of a q wave in V1 with a proportion of the positive QRS component in V1 < V2 > V3, predicted a right endocardial AP with a 100% specificity. In case of a positive QRS sum in V2, this ‘double transition’ pattern predicted a posteroseptal right endocardial AP with 99.5% specificity and 44% sensitivity. The positive predictive value was 97%. The only false positive was a midseptal AP. In the case of a negative or isoelectric QRS sum in V2, APs were located more laterally on the tricuspid annulus. Conclusion The combination of a q wave in V1 with a double QRS transition pattern in the precordial leads is highly specific of a right endocardial AP and rules out the need for CS or left-sided mapping.
Liverworts are known for their large chemical diversity. Much of this diversity is synthesized and enclosed within the oil bodies (OB), a synapomorphy of the lineage. OB contain the biosynthetic enzymes to produce and store large quantities of sesquiterpenoids and other compounds while limiting their cytotoxicity. Recently, there were important biochemical and molecular discoveries related to OB formation, diversity and biochemistry that allows the comparison with other secretory structures of land plants in an evo-devo perspective. In this review, we address and discuss the most recent advances in OB origin, development and function to understand the importance of these organelles in liverwort physiology and adaptation to the changing environment. Our mapping of OB-types and chemical compounds to the current liverwort phylogeny suggests that OB were already present in the most recent common ancestor of liverworts, supporting OB evolved as the first secretory structure in land plants. Still, we require a better sampling to define the macroevolutionary pattern governing the ancestral type of OB. We conclude that current efforts in finding molecular mechanisms responsible for this morphological and chemical diversity of secretory structures will help understand the evolution of each major group of land plants, and open new avenues in biochemical research of bioactive compounds for both bryophytes and vascular plants.
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The class Polytrichopsida are a phylogenetically isolated moss lineage of around 200 species. The nematodontous peristome found in most species has a fundamentally different structure from the arthrodontous peristome of the Bryopsida and may be independently evolved from an ancestral type of spore dehiscence apparatus. Within the class generic circumscriptions and relationships are now fairly confidently resolved and more or less congruent with the most developed pre-molecular taxonomy. Drawing on previously published datasets, we conducted a phylogenetic analysis of a novel matrix of terminals representing diversity across the Polytrichopsida. The class comprises 17 extant genera and two known only from fossils. Most of these are numerically small, the most notable exception being Pogonatum with over 50 species. Considering current phylogenetic hypotheses in the light of morphology and global distributions, Alophosia, Bartramiopsis and Lyellia, the earliest diverging lineages according to recent phylogenetic analyses, appear to be relicts, with scattered and disjunct distributions. All of these genera lack peristomes, while all later originating lineages have nematodontous peristomes developed from bundles of “u-shaped” whole cells. The genus Dawsonia, sister to all other peristomate taxa, differs in its unique peristome composed of long, bristle-like teeth arranged in concentric layers. Many members of some traditional genera found to be polyphyletic in recent studies are part of a southern hemisphere grade and only distantly related to the superficially similar northern hemisphere species with which they were historically classified. A large apical clade including eight genera accounts for the majority of the diversity, these being most speciose in northern temperate regions or the Asian tropics. Many of the Polytrichopsida are relatively large plants with well-developed vasculature and a “pseudo-mesophyll” capable of supporting relatively high rates of photosynthesis in moist, well-illuminated environments. With ten described species, Cenozoic fossils of Polytrichopsida are fairly numerous compared with other mosses. Records of fossils from older sediments have been rare, but recently several well-preserved fossils of Polytrichopsida have been found, most of which still await detailed description.
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