scholarly journals Species Phylogeny versus Gene Trees: A Case Study of an Incongruent Data Matrix Based on Paphiopedilum Pfitz. (Orchidaceae)

2021 ◽  
Vol 22 (21) ◽  
pp. 11393
Author(s):  
Marcin Górniak ◽  
Dariusz L. Szlachetko ◽  
Natalia Olędrzyńska ◽  
Aleksandra M. Naczk ◽  
Agata Mieszkowska ◽  
...  

The phylogeny of the genus Paphiopedilum based on the plastome is consistent with morphological analysis. However, to date, none of the analyzed nuclear markers has confirmed this. Topology incongruence among the trees of different nuclear markers concerns entire sections of the subgenus Paphiopedilum. The low-copy nuclear protein-coding gene PHYC was obtained for 22 species representing all sections and subgenera of Paphiopedilum. The nuclear-based phylogeny is supported by morphological characteristics and plastid data analysis. We assumed that an incongruence in nuclear gene trees is caused by ancestral homoploid hybridization. We present a model for inferring the phylogeny of the species despite the incongruence of the different tree topologies. Our analysis, based on six low-copy nuclear genes, is congruent with plastome phylogeny and has been confirmed by phylogenetic network analysis.

Parasitology ◽  
2011 ◽  
Vol 138 (13) ◽  
pp. 1760-1777 ◽  
Author(s):  
LAURA M. McDONAGH ◽  
JAMIE R. STEVENS

SUMMARYThe Calliphoridae include some of the most economically significant myiasis-causing flies in the world – blowflies and screwworm flies – with many being notorious for their parasitism of livestock. However, despite more than 50 years of research, key taxonomic relationships within the family remain unresolved. This study utilizes nucleotide sequence data from the protein-coding genes COX1 (mitochondrial) and EF1α (nuclear), and the 28S rRNA (nuclear) gene, from 57 blowfly taxa to improve resolution of key evolutionary relationships within the family Calliphoridae. Bayesian phylogenetic inference was carried out for each single-gene data set, demonstrating significant topological difference between the three gene trees. Nevertheless, all gene trees supported a Calliphorinae-Luciliinae subfamily sister-lineage, with respect to Chrysomyinae. In addition, this study also elucidates the taxonomic and evolutionary status of several less well-studied groups, including the genus Bengalia (either within Calliphoridae or as a separate sister-family), genus Onesia (as a sister-genera to, or sub-genera within, Calliphora), genus Dyscritomyia and Lucilia bufonivora, a specialised parasite of frogs and toads. The occurrence of cross-species hybridisation within Calliphoridae is also further explored, focusing on the two economically significant species Lucilia cuprina and Lucilia sericata. In summary, this study represents the most comprehensive molecular phylogenetic analysis of family Calliphoridae undertaken to date.


2012 ◽  
Vol 92 (3) ◽  
pp. 461-472 ◽  
Author(s):  
JiYoung Yang ◽  
Ho-Sung Yoon ◽  
Jae-Hong Pak

Yang, J., Yoon, H.-S. and Pak. J.-H. 2012. Phylogeny of Korean Rubus (Rosaceae) based on the second intron of the LEAFY gene. Can. J. Plant Sci. 92: 461–472. The second intron of the LEAFY gene was used for phylogenetic analysis of Rubus (Rosaceae). The LEAFY gene is conserved among a wide variety of plants and is known to be involved in the morphological evolution of plants. Sequence comparison of LEAFY homologues revealed the phylogenetic relationships of previously unresolved taxa, suggesting the usefulness of this marker rather than the ITS region for representing nuclear gene trees. In addition, a combined analysis of the trnL/F intergenic region of chloroplast DNA and the second intron of the LEAFY gene yielded more imformative data. Based on the data, it was inferred that evolution proceeded from herbs to woody plants, compound leaf to simple leaf, and pink petal to white petal within Korean Rubus taxa. Moreover, the LEAFY and trnL/F combined phylogeny had similar topology with the Rubus classification based on morphological characteristics. Therefore, our results indicate that LEAFY and trnL/F were valuable regions for analyzing the phylogenetic relationships among the Rubus taxa in Korea.


Author(s):  
Sievert Rohwer ◽  
Rebecca B. Harris ◽  
Hollie E. Walsh

Conspecific rape often increases male reproductive success. However, the haste and aggression of forced copulations suggests that males may sometimes rape heterospecific females, thus making rape a likely, but undocumented, source of hybrids between broadly sympatric species. We present evidence that heterospecific rape may be the source of hybrids between Black-footed and Laysan Albatrosses (Phoebastria nigripes, and P. immutabilis, respectively). Extensive field studies have shown that paired (but not unpaired) males of both of these albatross species use rape as a supplemental reproductive strategy. Between species differences in size, timing of laying, and aggressiveness suggest that Black-footed Albatrosses should be more successful than Laysan Albatrosses in heteropspecific rape attempts, and male Black-footed Albatrosses have been observed attempting to force copulations on female Laysan Albatrosses. Nuclear markers showed that the six hybrids we studied were F1s and mitochondrial markers showed that male Black-footed Albatrosses sired all six hybrids. The siring asymmetry found in our hybrids may have long persisted because an IM analysis suggests that long-term gene exchange between these species has been from Black-footed Albatrosses into Laysan Albatrosses. If hybrids are sired in heterospecific rapes, they presumably would be raised and sexually imprinted on Laysan Albatrosses, and two unmated hybrids in a previous study courted only Laysan Albatrosses.


AoB Plants ◽  
2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Nannie L Persson ◽  
Ingrid Toresen ◽  
Heidi Lie Andersen ◽  
Jenny E E Smedmark ◽  
Torsten Eriksson

Abstract The genus Potentilla (Rosaceae) has been subjected to several phylogenetic studies, but resolving its evolutionary history has proven challenging. Previous analyses recovered six, informally named, groups: the Argentea, Ivesioid, Fragarioides, Reptans, Alba and Anserina clades, but the relationships among some of these clades differ between data sets. The Reptans clade, which includes the type species of Potentilla, has been noticed to shift position between plastid and nuclear ribosomal data sets. We studied this incongruence by analysing four low-copy nuclear markers, in addition to chloroplast and nuclear ribosomal data, with a set of Bayesian phylogenetic and Multispecies Coalescent (MSC) analyses. A selective taxon removal strategy demonstrated that the included representatives from the Fragarioides clade, P. dickinsii and P. fragarioides, were the main sources of the instability seen in the trees. The Fragarioides species showed different relationships in each gene tree, and were only supported as a monophyletic group in a single marker when the Reptans clade was excluded from the analysis. The incongruences could not be explained by allopolyploidy, but rather by homoploid hybridization, incomplete lineage sorting or taxon sampling effects. When P. dickinsii and P. fragarioides were removed from the data set, a fully resolved, supported backbone phylogeny of Potentilla was obtained in the MSC analysis. Additionally, indications of autopolyploid origins of the Reptans and Ivesioid clades were discovered in the low-copy gene trees.


2019 ◽  
Vol 20 (20) ◽  
pp. 5167 ◽  
Author(s):  
Qiang Li ◽  
Yuanhang Ren ◽  
Xiaodong Shi ◽  
Lianxin Peng ◽  
Jianglin Zhao ◽  
...  

In the present study, we assembled and compared two mitogenomes from the Rhizopogon genus. The two mitogenomes of R. salebrosus and R. vinicolor comprised circular DNA molecules, with the sizes of 66,704 bp and 77,109 bp, respectively. Comparative mitogenome analysis indicated that the length and base composition of protein coding genes (PCGs), rRNA genes and tRNA genes varied between the two species. Large fragments aligned between the mitochondrial and nuclear genomes of both R. salebrosus (43.41 kb) and R. vinicolor (12.83 kb) indicated that genetic transfer between mitochondrial and nuclear genomes has occurred over evolutionary time of Rhizopogon species. Intronic regions were found to be the main factors contributing to mitogenome expansion in R. vinicolor. Variations in the number and type of introns in the two mitogenomes indicated that frequent intron loss/gain events occurred during the evolution of Rhizopogon species. Phylogenetic analyses based on Bayesian inference (BI) and Maximum likelihood (ML) methods using a combined mitochondrial gene set yielded identical and well-supported tree topologies, wherein Rhizopogon species showed close relationships with Agaricales species. This is the first study of mitogenomes within the genus Rhizopogon, and it provides a basis for understanding the evolution and differentiation of mitogenomes from the ectomycorrhizal fungal genus.


2009 ◽  
Vol 57 (4) ◽  
pp. 167 ◽  
Author(s):  
Gavin Huttley

Did the mammal radiation arise through initial divergence of prototherians from a common ancestor of metatherians and eutherians, the Theria hypothesis, or of eutherians from a common ancestor of metatherians and prototherians, the Marsupionta hypothesis? Molecular phylogenetic analyses of point substitutions applied to this problem have been contradictory – mtDNA-encoded sequences supported Marsupionta, nuclear-encoded sequences and RY (purine–pyrimidine)-recoded mtDNA supported Theria. The consistency property of maximum likelihood guarantees convergence on the true tree only with longer alignments. Results from analyses of genome datasets should therefore be impervious to choice of outgroup. We assessed whether important hypotheses concerning mammal evolution, including Theria/Marsupionta and the branching order of rodents, carnivorans and primates, are resolved by phylogenetic analyses using ~2.3 megabases of protein-coding sequence from genome projects. In each case, only two tree topologies were being compared and thus inconsistency in resolved topologies can only derive from flawed models of sequence divergence. The results from all substitution models strongly supported Theria. For the eutherian lineages, all models were sensitive to the outgroup. We argue that phylogenetic inference from point substitutions will remain unreliable until substitution models that better match biological mechanisms of sequence divergence have been developed.


Diversity ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 88
Author(s):  
Emily Fountain ◽  
Robert Cruickshank ◽  
Adrian Paterson

The delineation of species is important to the fields of evolution, ecology and conservation. The use of only a single line of evidence, e.g., morphology or a single gene sequence, may underestimate or overestimate the level of diversity within a taxon. This problem often occurs when organisms are morphologically similar but genetically different, i.e., for cryptic species. The Hadramphus genus contains four endangered, morphologically similar species of weevils, each endemic to a specific New Zealand region (Hadramphus spinipennis Chatham Islands, H. stilbocarpae Fiordland, H. tuberculatus McKenzie Country, H. pittospori Poor Knights Islands). The systematic relationships among these species are unclear. We used samples from these species and a closely related genus, Lyperobius huttoni, to obtain data from the mitochondrial gene cytochrome c oxidase subunit I and the nuclear gene internal transcribe spacer 2. In addition to the multi-locus coalescent approach, we modelled morphological characteristics combined with the genetic data. We found that H. spinipennis, H. tuberculatus and H. stilbocarpae were a closely related clade. Despite a strong morphological similarity, Hadramphus pittospori was found to be genetically distinct from the other Hadramphus species, which supports the resurrection of the monotypic genus Karocolens for this species.


2004 ◽  
Vol 64 (3a) ◽  
pp. 383-398
Author(s):  
M. L. Christoffersen ◽  
M. E. Araújo ◽  
M. A. M. Moreira

Total sequence phylogenies have low information content. Ordinary misconceptions are that character quality can be ignored and that relying on computer algorithms is enough. Despite widespread preference for a posteriori methods of character evaluation, a priori methods are necessary to produce transformation series that are independent of tree topologies. We propose a stepwise qualitative method for analyzing protein sequences. Informative codons are selected, alternative amino acid transformation series are analyzed, and most parsimonious transformations are hypothesized. We conduct four phylogenetic analyses of philodryanine snakes. The tree based on all nucleotides produces least resolution. Trees based on the exclusion of third positions, on an asymmetric step matrix, and on our protocol, produce similar results. Our method eliminates noise by hypothesizing explicit transformation series for each informative protein-coding amino acid. This approaches qualitative methods for morphological data, in which only characters successfully interpreted in a phylogenetic context are used in cladistic analyses. The method allows utilizing character information contained in the original sequence alignment and, therefore, has higher resolution in inferring a phylogenetic tree than some traditional methods (such as distance methods).


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