scholarly journals The first complete plastid genomes of Melastomataceae are highly structurally conserved

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2715 ◽  
Author(s):  
Marcelo Reginato ◽  
Kurt M. Neubig ◽  
Lucas C. Majure ◽  
Fabian A. Michelangeli

BackgroundIn the past three decades, several studies have predominantly relied on a small sample of the plastome to infer deep phylogenetic relationships in the species-rich Melastomataceae. Here, we report the first full plastid sequences of this family, compare general features of the sampled plastomes to other sequenced Myrtales, and survey the plastomes for highly informative regions for phylogenetics.MethodsGenome skimming was performed for 16 species spread across the Melastomataceae. Plastomes were assembled, annotated and compared to eight sequenced plastids in the Myrtales. Phylogenetic inference was performed using Maximum Likelihood on six different data sets, where putative biases were taken into account. Summary statistics were generated for all introns and intergenic spacers with suitable size for polymerase chain reaction (PCR) amplification and used to rank the markers by phylogenetic information.ResultsThe majority of the plastomes sampled are conserved in gene content and order, as well as in sequence length and GC content within plastid regions and sequence classes. Departures include the putative presence ofrps16andrpl2pseudogenes in some plastomes. Phylogenetic analyses of the majority of the schemes analyzed resulted in the same topology with high values of bootstrap support. Although there is still uncertainty in some relationships, in the highest supported topologies only two nodes received bootstrap values lower than 95%.DiscussionMelastomataceae plastomes are no exception for the general patterns observed in the genomic structure of land plant chloroplasts, being highly conserved and structurally similar to most other Myrtales. Despite the fact that the full plastome phylogeny shares most of the clades with the previously widely used and reduced data set, some changes are still observed and bootstrap support is higher. The plastome data set presented here is a step towards phylogenomic analyses in the Melastomataceae and will be a useful resource for future studies.

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 543 ◽  
Author(s):  
Jun Li ◽  
Deng-Feng Xie ◽  
Xian-Lin Guo ◽  
Zhen-Ying Zheng ◽  
Xing-Jin He ◽  
...  

Bupleurum L. (Apiaceae) is a perennial and herbal genus, most species of which have high medicinal value. However, few studies have been performed using plastome data in this genus, and the phylogenetic relationships have always been controversial. In this study, the plastid genomes of Bupleurum chinense and Bupleurum commelynoideum were sequenced, and their gene content, order, and structure were counted and analyzed. The only three published Bupleurum species (B. boissieuanum, B. falcatum, and B. latissimum) and other fifteen allied species were selected to conduct a series of comparative and phylogenetic analyses. The genomes of B. chinense and B. commelynoideum were 155,869 and 155,629 bp in length, respectively, both of which had a typical quadripartite structure. The genome length, structure, guanine and cytosine (GC) content, and gene distribution were highly similar to the other three Bupleurum species. The five Bupleurum species had nearly the same codon usages, and eight regions (petN-psbM, rbcL-accD, ccsA-ndhD, trnK(UUU)-rps16, rpl32-trnL(UAG)-ccsA, petA-psbJ, ndhF-rpl32, and trnP(UGG)-psaJ-rpl33) were found to possess relatively higher nucleotide diversity, which may be the promising DNA barcodes in Bupleurum. Phylogenetic analysis revealed that all Bupleurum species clustered into a monophyletic clade with high bootstrap support and diverged after the Chamaesium clade. Overall, our study provides new insights into DNA barcoding and phylogenetic relationship between Bupleurum and its related genera, and will facilitate the population genomics, conservation genetics, and phylogenetics of Bupleurum in Apiaceae.


2021 ◽  
Author(s):  
Caesar Al Jewari ◽  
Sandra L Baldauf

Phylogenomics uses multiple genetic loci to reconstruct evolutionary trees, under the stipulation that all combined loci share a common phylogenetic history, i.e., they are congruent. Congruence is primarily evaluated via single-gene trees, but these trees invariably lack sufficient signal to resolve deep nodes making it difficult to assess congruence at these levels. Two methods were developed to systematically assess congruence in multi-locus data. Protocol 1 uses gene jackknifing to measure deviation from a central mean to identify taxon-specific incongruencies in the form of persistent outliers. Protocol_2 assesses congruence at the sub-gene level using a sliding window. Both protocols were tested on a controversial data set of 76 mitochondrial proteins previously used in various combinations to assess the eukaryote root. Protocol_1 showed a concentration of outliers in under-sampled taxa, including the pivotal taxon Discoba. Further analysis of Discoba using Protocol_2 detected a surprising number of apparently exogenous gene fragments, some of which overlap with Protocol_1 outliers and others that do not. Phylogenetic analyses of the full data using the static LG-gamma evolutionary model support a neozoan-excavate root for eukaryotes (Discoba sister), which rises to 99-100% bootstrap support with data masked according to either Protocol_1 or Protocol_2. In contrast, site-heterogeneous (mixture) models perform inconsistently with these data, yielding all three possible roots depending on presence/absence/type of masking and/or extent of missing data. The neozoan-excavate root places Amorphea (including animals and fungi) and Diaphoretickes (including plants) as more closely related to each other than either is to Discoba (Jakobida, Heterolobosea, and Euglenozoa), regardless of the presence/absence of additional taxa.


2016 ◽  
Author(s):  
Scott V. Edwards ◽  
Alison Cloutier ◽  
Allan J. Baker

AbstractNoncoding markers have a particular appeal as tools for phylogenomic analysis because, at least in vertebrates, they appear less subject to strong variation in GC content among lineages. Thus far, ultraconserved elements (UCEs) and introns have been the most widely used noncoding markers. Here we analyze and study the evolutionary properties of a new type of noncoding marker, conserved non-exonic elements (CNEEs), which consists of noncoding elements that are estimated to evolve slower than the neutral rate across a set of species. Although they often include UCEs, CNEEs are distinct from UCEs because they are not ultraconserved, and, most importantly, the core region alone is analyzed, rather than both the core and its flanking regions. Using a data set of 16 birds plus an alligator outgroup, and ~3600 - ~3800 loci per marker type, we found that although CNEEs were less variable than UCEs or introns and in some cases exhibited a slower approach to branch resolution as determined by phylogenomic subsampling, the quality of CNEE alignments was superior to those of the other markers, with fewer gaps and missing species. Phylogenetic resolution using coalescent approaches was comparable among the three marker types, with most nodes being fully and congruently resolved. Comparison of phylogenetic results across the three marker types indicated that one branch, the sister group to the passerine+falcon clade, was resolved differently and with moderate (> 70%) bootstrap support between CNEEs and UCEs or introns. Overall, CNEEs appear to be promising as phylogenomic markers, yielding phylogenetic resolution as high as for UCEs and introns but with fewer gaps, less ambiguity in alignments and with patterns of nucleotide substitution more consistent with the assumptions of commonly used methods of phylogenetic analysis.


Phytotaxa ◽  
2014 ◽  
Vol 176 (1) ◽  
pp. 156 ◽  
Author(s):  
NALIN N. WIJAYAWARDENE ◽  
KEVIN D. HYDE ◽  
ERIO CAMPORESI ◽  
D. JAYARAMA BHAT ◽  
YU SONG ◽  
...  

A new species Homortomyces tamaricis is introduced from Cervia, Italy. It is distinct from H. combreti, the type species of this monotypic genus, in having smaller conidia, smaller paraphyses and shorter supporting cells. Morphologically Homortomyces is similar to Stilbospora, which groups in Diaporthales incertae sedis in maximum-likelihood analysis of LSU rDNA sequences. Maximum-likelihood analysis of the combined data set of LSU and ITS rDNA sequences indicates that Homortomyces species cluster with Tubeufiaceae with 77% bootstrap support, but group as a distinct clade with high bootstrap value (100%). These two genera show convergent evolution since both share very similar morphological characters, but have distinct phylogenetic lineages. Further phylogenetic analyses are needed, when more strains of Homortomyces and related genera are available, to resolve the genus familial placement. We maintain the genus in Dothideomycetes incertae sedis. No sexual state has yet been reported for this genus.


Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 765-775
Author(s):  
Rafael Zardoya ◽  
Axel Meyer

Abstract The complete nucleotide sequence (17,005 bp) of the mitochondrial genome of the caecilian Typhlonectes natans (Gymnophiona, Amphibia) was determined. This molecule is characterized by two distinctive genomic features: there are seven large 109-bp tandem repeats in the control region, and the sequence for the putative origin of replication of the L strand can potentially fold into two alternative secondary structures (one including part of the tRNACys). The new sequence data were used to assess the phylogenetic position of caecilians and to gain insights into the origin of living amphibians (frogs, salamanders, and caecilians). Phylogenetic analyses of two data sets—one combining protein-coding genes and the other combining tRNA genes—strongly supported a caecilian + frog clade and, hence, monophyly of modern amphibians. These two data sets could not further resolve relationships among the coelacanth, lungfishes, and tetrapods, but strongly supported diapsid affinities of turtles. Phylogenetic relationships among a larger set of species of frogs, salamanders, and caecilians were estimated with a mitochondrial rRNA data set. Maximum parsimony analysis of this latter data set also recovered monophyly of living amphibians and favored a frog + salamander (Batrachia) relationship. However, bootstrap support was only moderate at these nodes. This is likely due to an extensive among-site rate heterogeneity in the rRNA data set and the narrow window of time in which the three main groups of living amphibians were originated.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7480 ◽  
Author(s):  
Qi Chen ◽  
Xiaobo Wu ◽  
Dequan Zhang

Fritillaria cirrhosa D. Don, whose bulb is used in a well-known traditional Chinese medicine to relieve cough and eliminate phlegm, is one of the most important medicinal plants of Fritillaria L. The species is widely distributed among the alpine regions in southwestern China and possesses complex morphological variations in different distributions. A series of newly related species were reported, based on obscure morphological differences. As a result, F. cirrhosa and its closely related species constitute a taxonomically complex group. However, it is difficult to accurately identify these species and reveal their phylogenetic relationships using traditional taxonomy. Molecular markers and gene fragments have been adopted but they are not able to afford sufficient phylogenetic resolution in the genus. Here, we report the complete chloroplast genome sequences of F. cirrhosa and its closely related species using next generation sequencing (NGS) technology. Eight plastid genomes ranged from 151,058 bp to 152,064 bp in length and consisted of 115 genes. Gene content, gene order, GC content, and IR/SC boundary structures were highly similar among these genomes. SSRs and five large repeat sequences were identified and the total number of them ranged from 73 to 79 and 63 to 75, respectively. Six highly divergent regions were successfully identified that could be used as potential genetic markers of Fritillaria. Phylogenetic analyses revealed that eight Fritillaria species were clustered into three clades with strong supports and F. cirrhosa was closely related to F. przewalskii and F. sinica. Overall, this study indicated that the complete chloroplast genome sequence was an efficient tool for identifying species in taxonomically complex groups and exploring their phylogenetic relationships.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8392 ◽  
Author(s):  
Janice Valencia-D ◽  
José Murillo-A ◽  
Clara Inés Orozco ◽  
Carlos Parra-O ◽  
Kurt M. Neubig

Here we present the first two complete plastid genomes for Brunelliaceae, a Neotropical family with a single genus, Brunellia. We surveyed the entire plastid genome in order to find variable cpDNA regions for further phylogenetic analyses across the family. We sampled morphologically different species, B. antioquensis and B. trianae, and found that the plastid genomes are 157,685 and 157,775 bp in length and display the typical quadripartite structure found in angiosperms. Despite the clear morphological distinction between both species, the molecular data show a very low level of divergence. The amount of nucleotide substitutions per site is one of the lowest reported to date among published congeneric studies (π = 0.00025). The plastid genomes have gene order and content coincident with other COM (Celastrales, Oxalidales, Malpighiales) relatives. Phylogenetic analyses of selected superrosid representatives show high bootstrap support for the ((C,M)O) topology. The N-fixing clade appears as the sister group of the COM clade and Zygophyllales as the sister to the rest of the fabids group.


2021 ◽  
Author(s):  
Qiu-Ping Jiang ◽  
Megan Price ◽  
Xian-Lin Guo ◽  
Wei Gou ◽  
Song-Dong Zhou ◽  
...  

Abstract Background Subtribe Angelicinae is a large and taxonomically complex group of Apiaceae, encompassing Angelica, Archangelica, Coelopleurum, Conioselinum, Czernaevia, Glehnia, Levisticum and Ostericum that are distributed in the Northern Hemisphere, and whether this taxa is natural is debatable, especially between Angelica and Ostericum. To determine genommic evolution and phylogenetic relationships between Angelica, Ostericum, and related species, we newly assembled the complete plastid genome sequences of eight subtribe Angelicinae species and Melanosciadium pimpinelloideum using next-generation sequencing technology. Results The nine plastid genomes we sequenced were conserved, and their size ranged from 146765 bp to 164329 bp, showing the typical quadripartite circular structure with an overall GC content of 37.5–37.8%. IR boundary analyses showed that the genes in the LSC region transfer into the IR regions and the SSC region was relatively stable. Codon usage patterns were similar among these species and we identified 66–86 SSRs, with the most abundant SSR being mononucleotide. The Pi analyses showed that petA-psbJ(0.02778), atpI-atpH(0.17333) and petA-psbJ(0.04726) intergenic regions had the highest Pi values in Angelica, Ostericum, and ten species, respectively. Conclusions Ostericum exhibited significant differences in size of genomes, content of genes and tRNAs, GC content, some type of SSRs, and IR boundaries to Angelica, and phylogenetic analyses found the relatedness between Angelica and Ostericum is more distant in protein-coding genes of the plastid genomes trees and nrITS trees.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shaojuan Qian ◽  
Yonghong Zhang ◽  
Shiou Yih Lee

The complete chloroplast genomes of three species of Edgeworthia namely, Edgeworthia albiflora, Edgeworthia chrysantha, and Edgeworthia gardneri (Thymelaeaceae), are reported and characterized. The chloroplast genomes displayed a typical quadripartite structure with conserved genome arrangement and specific divergence. The genomes ranged in length from 172,708 to 173,621 bp and displayed similar GC content of 36.5–36.7%. A total of 138–139 genes were predicted, including 92–93 protein-coding, 38 tRNAs and eight rRNAs genes. Variation in the number of short simple repeats and inverted region boundaries of the three cp genomes were observed. A mutational hotspot was detected along the nucleotide sequence from the ndhF to the trnL-UAG genes. The chloroplast genome-based and internal transcribed spacer (ITS)-based phylogenetic analyses using maximum-likelihood (ML) and Bayesian inference (BI) revealed that E. albiflora diverged before E. chrysantha and E. gardneri and placed the Edgeworthia clade at the base of the Eurasian Daphne group with strong bootstrap support. With an effective taxonomic treatment of the species of Edgeworthia, further molecular analyses of their intra- and interspecific genetic variation are inclined to support the treatment of E. albiflora and E. gardneri as two natural groups. The genetic information obtained from this study will provide valuable genomic resources for the identification of additional species and for deducing the phylogenetic evolution of Edgeworthia.


2021 ◽  
Author(s):  
Paul Lorenzo Gaite ◽  
Wilson Aala, Jr ◽  
Michael Bacus ◽  
Christian Labrador ◽  
April Mae Numeron ◽  
...  

The technical limitations of capillary sequencing in providing insights on phylogeny have been greatly aided in recent years by the implementation of next generation sequencing platforms which can generate whole mitochondrial genome (mitogenome) sequences. In this study, enriched mitochondrial DNA of Cynopterus brachyotis from Mindanao, Philippines was sequenced using the Illumina MiSeq platform. A total of 653,967 clean paired-end reads was assembled using a MIRA-MITObim pipeline, resulting to a consensus mitogenome sequence length of 17,382 bases and a GC content of 41.48%, which is consistent with other published mitogenomes in fruit bats. The assembled C. brachyotis mitogenome was annotated using the MITOS online server and was able to resolve all mitochondrial genes, except for one transfer RNA gene (trnT) which may be further resolved by additional capillary sequencing of the region. Sequence analysis showed that the Philippine C. brachyotis is only 90%-91% homologous with other Cynopterus spp. based on its full mitogenome sequence. Phylogenetic analysis of fruit bat mitogenomes deposited in online repositories revealed that the Philippine C. brachyotis in this study has diverged from Asian Cynopterus, namely Cynopterus brachyotis and Cynopterus sphinx from other parts of Asia (100% bootstrap support) with the latter two forming a separate clade. This divergence at the species level was consistent with phylogentic inference using cytochrome oxidase 1 (CO1) and cytochrome B (cytb) gene markers. Our results strengthen the previously reported hypothesis that the C. brachyotis in the Philippines is distinct from its Asian counterparts and should be therefore elevated to a new species.


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