Phylogenetic analysis of DNA sequence data.

Author(s):  
Sergei A. Subbotin

Abstract The goal of phylogenetics is to construct relationships that are true representations of the evolutionary history of a group of organisms or genes. The history inferred from phylogenetic analysis is usually depicted as branching in tree-like diagrams or networks. In nematology, phylogenetic studies have been applied to resolve a wide range of questions dealing with improving classifications and testing evolution processes, such as co-evolution, biogeography and many others. There are several main steps involved in a phylogenetic study: (i) selection of ingroup and outgroup taxa for a study; (ii) selection of one or several gene fragments for a study; (iii) sample collection, obtaining PCR products and sequencing of gene fragments; (iv) visualization, editing raw sequence data and sequence assembling; (v) search for sequence similarity in a public database; (vi) making and editing multiple alignment of sequences; (vii) selecting appropriate DNA model for a dataset; (viii) phylogenetic reconstruction using minimum evolution, maximum parsimony, maximum likelihood and Bayesian inference; (ix) visualization of tree files and preparation of tree for a publication; and (x) sequence submission to a public database. Molecular phylogenetic study requires particularly careful planning because it is usually relatively expensive in terms of the cost in reagents and time.

Author(s):  
Sergei A. Subbotin

Abstract The goal of phylogenetics is to construct relationships that are true representations of the evolutionary history of a group of organisms or genes. The history inferred from phylogenetic analysis is usually depicted as branching in tree-like diagrams or networks. In nematology, phylogenetic studies have been applied to resolve a wide range of questions dealing with improving classifications and testing evolution processes, such as co-evolution, biogeography and many others. There are several main steps involved in a phylogenetic study: (i) selection of ingroup and outgroup taxa for a study; (ii) selection of one or several gene fragments for a study; (iii) sample collection, obtaining PCR products and sequencing of gene fragments; (iv) visualization, editing raw sequence data and sequence assembling; (v) search for sequence similarity in a public database; (vi) making and editing multiple alignment of sequences; (vii) selecting appropriate DNA model for a dataset; (viii) phylogenetic reconstruction using minimum evolution, maximum parsimony, maximum likelihood and Bayesian inference; (ix) visualization of tree files and preparation of tree for a publication; and (x) sequence submission to a public database. Molecular phylogenetic study requires particularly careful planning because it is usually relatively expensive in terms of the cost in reagents and time.


2008 ◽  
Vol 98 (5) ◽  
pp. 499-507 ◽  
Author(s):  
H.C. Zhang ◽  
G.X. Qiao

AbstractThree traditional tribes of Fordini, Pemphigini and Eriosomatini comprise Pemphiginae, and there are two subtribes in Fordini and Pemphigini, respectively. Most of the species in this subfamily live heteroecious holocyclic lives with distinct primary host specificity. The three tribes of Pemphigini (except Prociphilina), Eriosomatini and Fordini use three families of plants, Salicaceae (Populus), Ulmaceae (Ulums) and Anacardiaceae (Pistacia and Rhus), as primary hosts, respectively, and form galls on them. Therefore, the Pemphigids are well known as gall makers, and their galls can be divided into true galls and pseudo-galls in type. We performed the first molecular phylogenetic study of Pemphiginae based on molecular data (EF-1α sequences). Results show that Pemphiginae is probably not a monophylum, but the monophyly of Fordini is supported robustly. The monophyly of Pemphigini is not supported, and two subtribes in it, Pemphigina and Prociphilina, are suggested to be raised to tribal level, equal with Fordini and Eriosomatini. The molecular phylogenetic analysis does not show definite relationships among the four tribes of Pemphiginae, as in the previous phylogenetic study based on morphology. It seems that the four tribes radiated at nearly the same time and then evolved independently. Based on this, we can speculate that galls originated independently four times in the four tribes, and there is no evidence to support that true galls are preceded by pseudo-galls, as in the case of thrips and willow sawflies.


Mycotaxon ◽  
2020 ◽  
Vol 135 (4) ◽  
pp. 765-776
Author(s):  
Sana Jabeen ◽  
Arooj Naseer ◽  
Abdul Nasir Khalid

A new species, Russula rubricolor, was collected in the Himalayan forests of Pakistan. This species is morphologically characterized by the yellowish hymenium, bright red pileus that is convex to flat with central depression and finally infundibuliform and striate towards margin, becoming blackish red with age. The newly reported species is placed in Russula subsect. Maculatinae based molecular phylogenetic analysis of ITS sequence data and supported by the red pileus color.


Paleobiology ◽  
1994 ◽  
Vol 20 (3) ◽  
pp. 259-273 ◽  
Author(s):  
Andrew B. Smith ◽  
D. T. J. Littlewood

Molecular data are becoming an indispensable tool for the reconstruction of phylogenies. Fossil molecular data remain scarce, but have the potential to resolve patterns of deep branching and provide empirical tests of tree reconstruction techniques. A total evidence approach, combining and comparing complementary morphological, molecular and stratigraphical data from both recent and fossil taxa, is advocated as the most promising way forward because there are several well-established problems that can afflict the analysis of molecular sequence data sometimes resulting in spurious tree topologies. The integration of evidence allows us to: (1) choose suitable taxa for molecular phylogenetic analysis for the question at hand; (2) discriminate between conflicting hypotheses of taxonomic relationship and phylogeny; (3) evaluate procedures and assumptions underlying methods of building trees; and (4) estimate rates of molecular evolution in the geological past. Paleontology offers a set of independent data for comparison and corroboration of analyses and provides the only direct means of calibrating molecular trees, thus giving insight into rates of molecular evolution in the geological past.


Zootaxa ◽  
2017 ◽  
Vol 4232 (4) ◽  
pp. 523 ◽  
Author(s):  
XIAOHONG ZHANG ◽  
JINFENG HAO ◽  
YU XIA ◽  
YAGE CHANG ◽  
DAOCHUAN ZHANG ◽  
...  

The higher taxa classification and phylogeny of the insect order Orthoptera have long been controversial. Hexamerin, as a member of the highly conserved arthropod hemocyanin superfamily, has been shown to be a good marker for the phylogenetic study of insects. However, few studies have used hexamerins on the phylogeny of Orthoptera. In this study, we determined twenty-seven different hexamerin subunit type sequences in seventeen speices of Orthoptera. In order to infer the phylogenetic relationships among the superfamilies within Orthoptera and test the monophyly of Orthoptera, phylogenic trees were reconstructed using Neighbor-Joining (NJ) and Bayesian inference (BI) methods with two dipluran and three hymenopteran hexamerin sequences as outgroups. The result supported the monophyly of Orthoptera, which includes two monophyletic suborders Caelifera and Ensifera. The Caelifera includes Acridoidea, Eumastacoidea, Tetrigoidea and Tridactyloidea, and the Ensifera includes Tettigonioidea, Grylloidea and Gryllotalpoidea. Our study is basically consistent with the study of morphological classification. In addition, our study indicates that a relatively comprehensive taxa sampling is essential to solve some problems in phylogenetic reconstruction. 


MycoKeys ◽  
2021 ◽  
Vol 85 ◽  
pp. 57-71
Author(s):  
Taichang Mu ◽  
Zhaoxue Zhang ◽  
Rongyu Liu ◽  
Shubin Liu ◽  
Zhuang Li ◽  
...  

Colletotrichum has numerous host range and distribution. Its species are important plant pathogens, endophytes and saprobes. Colletotrichum can cause regular or irregular depressions and necrotic lesions in the epidermal tissues of plants. During this research Colletotrichum specimens were collected from Mengyin County, Shandong Province, China. A multi-locus phylogenetic analysis of ITS, GAPDH, CHS-1, ACT, TUB2, CAL and GS sequence data combined with morphology, revealed a new species and two known species, viz. C. mengyinense sp. nov., C. gloeosporioides and C. pandanicola, belonging to the C. gloeosporioides species complex. The new species is described and illustrated in this paper and compared with taxa in the C. gloeosporioides species complex.


1999 ◽  
Vol 65 (12) ◽  
pp. 5586-5589 ◽  
Author(s):  
Ken Takai ◽  
Koki Horikoshi

ABSTRACT Molecular phylogenetic analysis of a naturally occurring microbial community in a deep-subsurface geothermal environment indicated that the phylogenetic diversity of the microbial population in the environment was extremely limited and that only hyperthermophilic archaeal members closely related to Pyrobaculum were present. All archaeal ribosomal DNA sequences contained intron-like sequences, some of which had open reading frames with repeated homing-endonuclease motifs. The sequence similarity analysis and the phylogenetic analysis of these homing endonucleases suggested the possible phylogenetic relationship among archaeal rRNA-encoded homing endonucleases.


2015 ◽  
Vol 22 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Fahad M.A. Al-Hemaid ◽  
M. Ajmal Ali ◽  
Joongku Lee ◽  
Soo-Yong Kim ◽  
Md. Oliur Rahman

The present study explored molecular phylogenetic analysis of 28 species of Euphorbia L. for the identification and establishment of molecular evolutionary relationships of Euphorbia scordifolia Jacq. within the genus based on the internal transcribed spacers (ITS) sequences (ITS1-5.8S-ITS2) of nuclear ribosomal DNA (nrDNA). The sequence similarity search using Basic Local Alignment Search Tool (BLAST) of the ITS sequence of E. scordifolia showed the closest sequence similarity to E. supina Raf. The analysis of ITS sequence data revealed four major clades consistent with subgeneric classifications of the genus. Molecular data support placement of E. scordifolia in the subgenus Chamaesyce.Bangladesh J. Plant Taxon. 22(2): 111-118, 2015 (December)


Zootaxa ◽  
2019 ◽  
Vol 4543 (1) ◽  
pp. 127 ◽  
Author(s):  
SEUNGGWAN SHIN ◽  
HEUNGSIK LEE ◽  
SEUNGHWAN LEE

Here we propose a new monophyletic subfamily, the Chaetosciarinae, based on previous morphological cladistic and molecular phylogenetic studies. This new subfamily includes the genera Chaetosciara Frey, Mouffetina Frey, Schwenckfeldina Frey, and Scythropochroa Enderlein. We also provide a definition of the new subfamily Chaetosciarinae and describe common morphological key characters. Three Korean Chaetosciarinae species in three genera are reported, all of which are new to Korea and one (Scythropochroa pseudoquercicola sp. nov.) of which is new to science. A previous molecular phylogenetic study designated Scy. pseudoquercicola as an unidentified species. Our study provides examined species information for members of this new subfamily to accompany the GenBank accession numbers published by a previous molecular phylogenetic study. Furthermore, we present a multigene molecular phylogenetic analysis for the Chaetosciarinae. 


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