scholarly journals Plastome Characterization and Phylogenomic Analysis Yield New Insights into the Evolutionary Relationships among the Species of the Subgenus Bryocles (Hosta; Asparagaceae) in East Asia

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1980
Author(s):  
Ji-Young Yang ◽  
Mi-Jung Choi ◽  
Seon-Hee Kim ◽  
Hyeok-Jae Choi ◽  
Seung-Chul Kim

The genus Hosta, which has a native distribution in temperate East Asia and a number of species ranging from 23 to 40, represents a taxonomically important and ornamentally popular plant. Despite its taxonomic and horticultural importance, the genus Hosta has remained taxonomically challenging owing to insufficient diagnostic features, continuous morphological variation, and the process of hybridization and introgression, making species circumscription and phylogenetic inference difficult. In this study, we sequenced 11 accessions of Hosta plastomes, including members of three geographically defined subgenera, Hosta, Bryocles, and Giboshi, determined the characteristics of plastomes, and inferred their phylogenetic relationships. We found highly conserved plastomes among the three subgenera, identified several mutation hotspots that can be used as barcodes, and revealed the patterns of codon usage bias and RNA editing sites. Five positively selected plastome genes (rbcL, rpoB, rpoC2, rpl16, and rpl20) were identified. Phylogenetic analysis suggested (1) the earliest divergence of subg. Hosta, (2) non-monophyly of subg. Bryocles and its two sections (Lamellatae and Stoloniferae), (3) a sister relationship between H. sieboldiana (subg. Giboshi) and H. ventricosa (subg. Bryocles), and (4) reciprocally monophyletic and divergent lineages of H. capitata in Korea and Japan, requiring further studies of their taxonomic distinction.

2007 ◽  
Vol 57 (2) ◽  
pp. 276-286 ◽  
Author(s):  
Ivo M. Chelo ◽  
Líbia Zé-Zé ◽  
Rogério Tenreiro

The phylogenetic structure of the Leuconostoc–Oenococcus–Weissella clade was evaluated by comparison of 16S rRNA gene, dnaA, gyrB, rpoC and dnaK sequence analysis. Phylogenies obtained with the different genes were in overall good agreement and a well-supported, almost fully resolved phylogenetic tree was obtained when the combined data were analysed in a Bayesian approach. A rapid basal diversification of the three genera is suggested. Evolutionary rates of the 16S rRNA gene in these genera seem to be different and specifically related to the evolution of this group, revealing the importance of this sequence in the constitution of the present taxonomy, but preventing its straightforward use in phylogenetic inference.


Nematology ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 377-400 ◽  
Author(s):  
Kimkhuy Khun ◽  
Wilfrida Decraemer ◽  
Marjolein Couvreur ◽  
Gerrit Karssen ◽  
Hanne Steel ◽  
...  

Hirschmanniella mucronatapopulations isolated from two Cambodian provinces were characterised using morphological, morphometric and molecular criteria. Examination of 1024 specimens from 60 different paddy fields revealed high intraspecific variation in morphology and morphometrics, especially in tail terminus shape and stylet length. Sequence results confirmed that morphologically divergent individuals represent a single species, suggesting that neglecting morphological variation has led to an overestimation ofHirschmannielladiversity in former studies. Phylogenetic analysis of the SSU, D2-D3, LSU and ITS1-5.8S-ITS2 regions revealed three concordant clades,H. mucronatahaving a sister relationship withH. kwazunaandH. loofi. Plotting the diagnostic features, including tail terminus shape, stylet length and lip region morphology on the phylogenetic framework, revealed that none of them supported the clades and represented convergent features. All three molecular markers were able to discriminate allHirschmanniellaspecies, but the D2-D3 region was the easiest, fastest and most successful region to be amplified. Species delimitation and the diagnostic features ofHirschmanniellawere re-evaluated.Hirschmanniella abnormalis and H. exactaare considered to be junior synonyms ofH. oryzaeandH. mannaiaspecies inquirenda. Finally, a list of valid species with indication of synonyms and a polytomous key are provided.


2017 ◽  
Vol 49 (5) ◽  
pp. 457-466 ◽  
Author(s):  
Evgeny A. DAVYDOV ◽  
Lidia S. YAKOVCHENKO

AbstractRhizocarpon smaragdulum Davydov & Yakovchenko sp. nov. is described and a phylogenetic analysis (ITS, mtSSU) is presented, confirming its distinctiveness and indicating a sister relationship with R. suomiense and R. subgeminatum. The species is unique among yellow Rhizocarpon species in having a single hyaline ascospore per ascus. The phylogenetic tree suggests that the number of ascospores per ascus has been reduced in Rhizocarpon more than once during the course of its evolution. Two new distributional records are also reported: Rhizocarpon atroflavescens is new for Siberia and R. norvegicum is new for the Altai Mountains. Rhizocarpon norvegicum in this region grows on rocks and is also lichenicolous on Acarospora bullata.


Zootaxa ◽  
2018 ◽  
Vol 4514 (4) ◽  
pp. 487
Author(s):  
ANDRÉS R. ACOSTA-GALVIS ◽  
JEFFREY W. STREICHER ◽  
LUIGI MANUELLI ◽  
TRAVIS CUDDY ◽  
RAFAEL O. DE SÁ

Among New World direct-developing frogs belonging to the clade Brachycephaloidea (= Terraranae), there are several genera with uncertain phylogenetic placements. One notable example is the genus Niceforonia Goin & Cochran 1963, which includes three species that are endemic to Colombia. Three specimens of the species Niceforonia nana were collected and for the first time the genus is included in a molecular phylogenetic analysis of mitochondrial (mtDNA; 12S and 16S) and nuclear (nucDNA; TYR and RAG1) markers. Molecular phylogenetic inference based on concatenated and separate mtDNA and nucDNA analyses recovered Niceforonia nana nested within Hypodactylus Hedges et al. 2008, rendering the latter genus paraphyletic. Consequently, herein we place the genus Hypodactylus in the synonymy of Niceforonia to resolve the paraphyly and place Niceforonia in the subfamily Hypodactylinae. Based on our revised concept of the genus Niceforonia we conducted preliminary morphological comparisons using specimens and literature descriptions. Finally, Nicefornia nana is quite divergent from other species of Niceforonia (uncorrected genetic distances of ca. 10% 16S and 7% TYR) suggesting that further taxonomic revision may be warranted. 


Zootaxa ◽  
2020 ◽  
Vol 4768 (2) ◽  
pp. 271-281 ◽  
Author(s):  
KAZUTAKA YAMADA ◽  
MASAMI HAYASHI

The genus Alpagut Kıyak, 1995, is recorded from East Asia for the first time based on the description of A. masakazui sp. nov. from Japan. Habitus images and illustrations of diagnostic features, including genitalia structures, are provided. The loculus capsulae of A. masakazui sp. nov. is discussed. The presence of a metacoxal adhesive pad is reconfirmed in Dipsocoridae along with a discussion of its morphology. 


Zootaxa ◽  
2020 ◽  
Vol 4718 (1) ◽  
pp. 87-94
Author(s):  
PAWEŁ JAŁOSZYŃSKI

Until now, four species of Clidicus Laporte were found in Sri Lanka, three known from female specimens only. Clidicus minilankanus sp. n., is described, and compared to all remaining sympatric congeners. The Sri Lankan species may form a monophyletic group characterized by several morphological oddities: the head only slightly impressed posteromedially, with a large portion of vertex and frons not divided longitudinally; the pronotum quadrangular and flattened, with vestigial or absent posterior ‘collar’, and the transverse groove that demarcates it from the disc lacking pits or even entirely or partly obliterated; and the metaventrite strongly shortened, so that meso- and metacoxae are nearly adjacent. These characters may justify resurrecting Erineus Walker, a junior synonym of Clidicus (proposed for the first described Sri Lankan species, C. monstrosus (Walker)), as a valid name for a subgenus. This problem must be addressed by a phylogenetic analysis of all Clidicus species, to establish evolutionary relationships within this interesting genus. 


Genes ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 490 ◽  
Author(s):  
Sharma ◽  
Gupta

The class Hematozoa encompasses several clinically important genera, including Plasmodium, whose members cause the major life-threating disease malaria. Hence, a good understanding of the interrelationships of organisms from this class and reliable means for distinguishing them are of much importance. This study reports comprehensive phylogenetic and comparative analyses on protein sequences on the genomes of 28 hematozoa species to understand their interrelationships. In addition to phylogenetic trees based on two large datasets of protein sequences, detailed comparative analyses were carried out on the genomes of hematozoa species to identify novel molecular synapomorphies consisting of conserved signature indels (CSIs) in protein sequences. These studies have identified 79 CSIs that are exclusively present in specific groups of Hematozoa/Plasmodium species, also supported by phylogenetic analysis, providing reliable means for the identification of these species groups and understanding their interrelationships. Of these CSIs, six CSIs are specifically shared by all hematozoa species, two CSIs serve to distinguish members of the order Piroplasmida, five CSIs are uniquely found in all Piroplasmida species except B. microti and two CSIs are specific for the genus Theileria. Additionally, we also describe 23 CSIs that are exclusively present in all genome-sequenced Plasmodium species and two, nine, ten and eight CSIs which are specific for members of the Plasmodium subgenera Haemamoeba, Laverania, Vinckeia and Plasmodium (excluding P. ovale and P. malariae), respectively. Additionally, our work has identified several CSIs that support species relationships which are not evident from phylogenetic analysis. Of these CSIs, one CSI supports the ancestral nature of the avian-Plasmodium species in comparison to the mammalian-infecting groups of Plasmodium species, four CSIs strongly support a specific relationship of species between the subgenera Plasmodium and Vinckeia and three CSIs each that reliably group P. malariae with members of the subgenus Plasmodium and P. ovale within the subgenus Vinckeia, respectively. These results provide a reliable framework for understanding the evolutionary relationships among the Plasmodium/Piroplasmida species. Further, in view of the exclusivity of the described molecular markers for the indicated groups of hematozoa species, particularly large numbers of unique characteristics that are specific for all Plasmodium species, they provide important molecular tools for biochemical/genetic studies and for developing novel diagnostics and therapeutics for these organisms.


2020 ◽  
Author(s):  
Benedict King

Abstract The incorporation of stratigraphic data into phylogenetic analysis has a long history of debate but is not currently standard practice for paleontologists. Bayesian tip-dated (or morphological clock) phylogenetic methods have returned these arguments to the spotlight, but how tip dating affects the recovery of evolutionary relationships has yet to be fully explored. Here I show, through analysis of several data sets with multiple phylogenetic methods, that topologies produced by tip dating are outliers as compared to topologies produced by parsimony and undated Bayesian methods, which retrieve broadly similar trees. Unsurprisingly, trees recovered by tip dating have better fit to stratigraphy than trees recovered by other methods under both the Gap Excess Ratio (GER) and the Stratigraphic Completeness Index (SCI). This is because trees with better stratigraphic fit are assigned a higher likelihood by the fossilized birth-death tree model. However, the degree to which the tree model favors tree topologies with high stratigraphic fit metrics is modulated by the diversification dynamics of the group under investigation. In particular, when net diversification rate is low, the tree model favors trees with a higher GER compared to when net diversification rate is high. Differences in stratigraphic fit and tree topology between tip dating and other methods are concentrated in parts of the tree with weaker character signal, as shown by successive deletion of the most incomplete taxa from two data sets. These results show that tip dating incorporates stratigraphic data in an intuitive way, with good stratigraphic fit an expectation that can be overturned by strong evidence from character data. [fossilized birth-death; fossils; missing data; morphological clock; morphology; parsimony; phylogenetics.]


Author(s):  
Benoit Morel ◽  
Pierre Barbera ◽  
Lucas Czech ◽  
Ben Bettisworth ◽  
Lukas Hübner ◽  
...  

Abstract Numerous studies covering some aspects of SARS-CoV-2 data analyses are being published on a daily basis, including a regularly updated phylogeny on nextstrain.org. Here, we review the difficulties of inferring reliable phylogenies by example of a data snapshot comprising a quality-filtered subset of 8, 736 out of all 16, 453 virus sequences available on May 5, 2020 from gisaid.org. We find that it is difficult to infer a reliable phylogeny on these data due to the large number of sequences in conjunction with the low number of mutations. We further find that rooting the inferred phylogeny with some degree of confidence either via the bat and pangolin outgroups or by applying novel computational methods on the ingroup phylogeny does not appear to be credible. Finally, an automatic classification of the current sequences into sub-classes using the mPTP tool for molecular species delimitation is also, as might be expected, not possible, as the sequences are too closely related. We conclude that, although the application of phylogenetic methods to disentangle the evolution and spread of COVID-19 provides some insight, results of phylogenetic analyses, in particular those conducted under the default settings of current phylogenetic inference tools, as well as downstream analyses on the inferred phylogenies, should be considered and interpreted with extreme caution.


Sign in / Sign up

Export Citation Format

Share Document