The cereal rust mite Abacarus hystrix (Acari: Eriophyoidea) is a complex of species: evidence from mitochondrial and nuclear DNA sequences

2009 ◽  
Vol 100 (3) ◽  
pp. 263-272 ◽  
Author(s):  
A. Skoracka ◽  
M. Dabert
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Sequence Divergence ◽  
28S Rdna ◽  
Host Specialization ◽  
Coi Gene ◽  
Grass Species ◽  
Data Set ◽  
Eriophyoid Mites ◽  
Region Data

AbstractThe cereal rust mite Abacarus hystrix (Nalepa), a significant pest of grasses, has been regarded as one of a few exceptions among eriophyoid mites with reference to the pattern of host plant utilization. At least 60 grass species have been recorded as its hosts. Thus, the mite has long been considered as a host generalist in which host specialization would not be likely to evolve. However, recent studies have revealed that host-associated specialization is possible in A. hystrix. Here, we aimed to discriminate between the three populations of A. hystrix associated with the different hosts (namely quackgrass, ryegrass and smooth brome) on the basis of mitochondrial (COI) and nuclear (D2 region of 28S rDNA) DNA sequences. The phylogenetic trees obtained with the maximum likelihood analysis of both COI and D2 region data sets showed that host-adapted strains of A. hystrix form distinct clades. Furthermore, on the COI nucleotide tree, the quackgrass- and brome-associated strains were internally divided each into two well-supported monophyletic clusters. The nucleotide D2 region data set tree showed that brome-associated strain is polyphyletic in origin. There is clear co-variation of DNA results with earlier morphological and ecological traits, as well as the results of crossing experiments. We showed that reproductively incompatible strains of A. hystrix exhibit more than 20% sequence divergence in the COI gene and 0.2% sequence divergence in the D2 28S rDNA. Our results did not confirm the placement of three host-associated strains of A. hystrix within one, ostensibly generalist, species.

Pycnoclavella stolonialis n. sp. (Tunicata: Ascidiacea), with phylogenetic and distributional remarks on the genus in Europe

Zootaxa ◽  
2010 ◽  
Vol 2407 (1) ◽  
pp. 51 ◽  
Author(s):  
R. PÉREZ-PORTELA ◽  
C. E. GOODWIN ◽  
B. E. PICTON ◽  
X. TURON
Keyword(s):  
New Species ◽  
Phylogenetic Trees ◽  
Sequence Divergence ◽  
Molecular Data ◽  
Coi Gene ◽  
Irish Sea ◽  
Colony Structure ◽  
Colonial Ascidian ◽  
Sea Squirt ◽  
The Irish Sea

Morphological and molecular data based on the COI gene were used to describe a new species of the colonial ascidian genus Pycnoclavella. The new species, P. stolonialis, is widespread sublittorally in the Irish Sea and also occurs on the western Irish coast, Wales and eastern England and may be locally common. It has been commonly known as the ‘pin head’ sea squirt since first recorded from Northern Ireland in 1984 but has not yet been formally described. P. stolonialis is the only described species of Pycnoclavella combining the presence of stolons, peribranchial incubation mode and a larva lacking an otolith. In addition, it features ca. 10% sequence divergence with the closest species of the genus in our phylogenetic trees. P. stolonialis showed intermediate characters between two groups of Pycnoclavella; the stanleyi and the aurilucens groups. Larval morphology and molecular data supported the inclusion of P. stolonialis within the aurilucens group, but the stolonial colony structure is characteristic of the stanleyi group. This implies that colony structure may not be a good character for separating these two groups. New information on distribution is given for P. atlantica, P. aurilucens and P. communis.

Clarification of the systematic position ofCercariaeum crassumWesenberg-Lund, 1934 (Digenea), based on karyological analysis and DNA sequences

2011 ◽  
Vol 86 (3) ◽  
pp. 293-301 ◽  
Author(s):  
R. Petkevičiūtė ◽  
V. Stunžėnas ◽  
G. Stanevičiūtė
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Developmental Stages ◽  
Sequence Divergence ◽  
Sister Group ◽  
Systematic Position ◽  
Life Cycles ◽  
Significant Information ◽  
Rdna Sequences ◽  
Species Specific

AbstractChromosome set and rDNA sequences of the larval digeneanCercariaeum crassumwere analysed in order to clarify its systematic position and possible adult form. Parasites were obtained from the sphaeriid bivalvePisidium amnicum, collected in Lithuanian and Finnish rivers. The karyotype is shown to consist of five pairs (2n = 10) of large, up to 14 μm, chromosomes. Complement, composed of a low diploid number of exclusively bi-armed elements, presumably arose through Robertsonian fusions of acrocentric chromosomes. Consistent with a Robertsonian-derived karyotype, one or two small, metacentric, mitotically stable B chromosomes were detected in the cells of parthenitae isolated from some host individuals. A phylogenetic analysis using rDNA internal transcribed spacer 2 (ITS2) and 28S sequences corroborates the allocation ofC. crassumto the family Allocreadiidae. In neighbour-joining and maximum parsimony phylogenetic treesC. crassumclusters into one clade withAllocreadiumspp., and is the closest sister group in relation toA. isoporum; the level of rDNA sequence divergence between them (2.67% for ITS2 and 1.16% for 28S) is consistent with the level expected for intrageneric variation. The present study adds significant information to a database for establishing species-specific characters for confident characterization of different developmental stages of allocreadiid species, clarification of their life cycles and evaluation of intra- and interspecific variability.

Phylogeny of the genus Scathophaga (Diptera: Scathophagidae) inferred from mitochondrial DNA sequences

2001 ◽  
Vol 79 (3) ◽  
pp. 517-524 ◽  
Author(s):  
M V Bernasconi ◽  
J Pawlowski ◽  
C Valsangiacomo ◽  
J -C Piffaretti ◽  
P I Ward
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Coi Gene ◽  
Similar Species ◽  
Mitochondrial Cytochrome ◽  
Cyt B ◽  
Protein Coding ◽  
Scathophaga Stercoraria ◽  
Mitochondrial Cytochrome B ◽  
Cyt B Gene

Scathophaga stercoraria has been used for a large number of studies in animal ecology and evolution. Morphological phylogenetic work on the relationships among flies of the family Scathophagidae in general, and the genus Scathophaga in particular, has led to limited or incomplete conclusions. We addressed these relationships by sequencing 810 base pairs (bp) from the mitochondrial cytochrome oxidase subunit I (COI) gene and 738 bp of the mitochondrial cytochrome b (Cyt b) gene in 16 species of Scathophagidae. Phylogenetic analysis of these two protein-coding genes allows us to resolve relatively well the relationships within the genus Scathophaga, using both separate and combined (COI + Cyt b) data. Most of the phylogenetic trees generated by our data support the following relationships: (((S. analis + S. inquinata) + S. lutaria) + S. cineraria + (S. taeniopa + S. suilla + S. incola) + S. furcata + S. tropicalis). The most noteworthy findings are that (i) S. obscura and S. tinctinervis, which were formerly placed in the genus Coniosternum, form a sibling species cluster; (ii) S. taeniopa and S. suilla, which are morphologically very similar species, are clearly distinct taxa; (iii) S. analis, considered a doubtful species in the Catalogue of Palearctic Diptera, could be a synonym of S. inquinata; and (iv) the South American S. tropicalis and the Old World S. stercoraria are not sister-species.

scholarly journals Mitochondrial DNA Sequence Phylogeny of Daucus

2020 ◽  
Vol 45 (2) ◽  
pp. 403-408 ◽  
Author(s):  
David M. Spooner ◽  
Holly Ruess ◽  
Philipp Simon ◽  
Douglas Senalik
Keyword(s):  
Mitochondrial Dna ◽  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Plastid Dna ◽  
Nuclear Data ◽  
Bootstrap Support ◽  
Illumina Hiseq ◽  
Data Set ◽  
Closely Related Species ◽  
Mitochondrial Sequences

Abstract—We explored the phylogenetic utility of mitochondrial DNA sequences in Daucus and compared the results with prior phylogenetic results using the same 36 accessions of Daucus (and two additional outgroups) with plastid DNA sequences and with other nuclear results. As in the plastid study we used Illumina HiSeq sequencer to obtain resequencing data of the same accessions of Daucus and outgroups, and analyzed the data with maximum parsimony and maximum likelihood. We obtained data from 47 of 71 total mitochondrial genes but only 17 of these 47 genes recovered major clades that were common in prior plastid and nuclear studies. Our phylogenetic trees of the concatenated data set of 47 genes were moderately resolved, with 100% bootstrap support for most of the external and many of the internal clades, except for the clade of D. carota and its most closely related species D. syrticus. There are areas of hard incongruence with phylogenies using plastid and nuclear data. In agreement with other studies, we conclude that mitochondrial sequences are generally poor phylogenetic markers, at least at the genus level, despite their utility in some other studies.

scholarly journals Annonaceae substitution rates: a codon model perspective

2014 ◽  
Vol 36 (spe1) ◽  
pp. 108-117 ◽  
Author(s):  
Lars Willem Chatrou ◽  
Michael David Pirie ◽  
Robin Van Velzen ◽  
Freek Theodoor Bakker
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Sequence Divergence ◽  
High Ratio ◽  
Molecular Dating ◽  
Codon Model ◽  
Synonymous Substitutions ◽  
Branch Lengths

The Annonaceae includes cultivated species of economic interest and represents an important source of information for better understanding the evolution of tropical rainforests. In phylogenetic analyses of DNA sequence data that are used to address evolutionary questions, it is imperative to use appropriate statistical models. Annonaceae are cases in point: Two sister clades, the subfamilies Annonoideae and Malmeoideae, contain the majority of Annonaceae species diversity. The Annonoideae generally show a greater degree of sequence divergence compared to the Malmeoideae, resulting in stark differences in branch lengths in phylogenetic trees. Uncertainty in how to interpret and analyse these differences has led to inconsistent results when estimating the ages of clades in Annonaceae using molecular dating techniques. We ask whether these differences may be attributed to inappropriate modelling assumptions in the phylogenetic analyses. Specifically, we test for (clade-specific) differences in rates of non-synonymous and synonymous substitutions. A high ratio of nonsynonymous to synonymous substitutions may lead to similarity of DNA sequences due to convergence instead of common ancestry, and as a result confound phylogenetic analyses. We use a dataset of three chloroplast genes (rbcL, matK, ndhF) for 129 species representative of the family. We find that differences in branch lengths between major clades are not attributable to different rates of non-synonymous and synonymous substitutions. The differences in evolutionary rate between the major clades of Annonaceae pose a challenge for current molecular dating techniques that should be seen as a warning for the interpretation of such results in other organisms.

Identification of Neoceratitis asiatica (Becker) (Diptera: Tephritidae) based on morphological characteristics and DNA barcode

Zootaxa ◽  
2017 ◽  
Vol 4363 (4) ◽  
pp. 553
Author(s):  
SHAOKUN GUO ◽  
JIA HE ◽  
ZIHUA ZHAO ◽  
LIJUN LIU ◽  
LIYUAN GAO ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Gap Analysis ◽  
Dna Barcode ◽  
Morphological Characteristics ◽  
Coi Gene ◽  
Economic Losses ◽  
Morphological Identification ◽  
Lycium Barbarum ◽  
Accurate Identification

Neoceratitis asiatica (Becker), which especially infests wolfberry (Lycium barbarum L.), could cause serious economic losses every year in China, especially to organic wolfberry production. In some important wolfberry plantings, it is difficult and time-consuming to rear the larvae or pupae to adults for morphological identification. Molecular identification based on DNA barcode is a solution to the problem. In this study, 15 samples were collected from Ningxia, China. Among them, five adults were identified according to their morphological characteristics. The utility of mitochondrial DNA (mtDNA) cytochrome c oxidase I (COI) gene sequence as DNA barcode in distinguishing N. asiatica was evaluated by analysing Kimura 2-parameter distances and phylogenetic trees. There were significant differences between intra-specific and inter-specific genetic distances according to the barcoding gap analysis. The uncertain larval and pupal samples were within the same cluster as N. asiatica adults and formed sister cluster to N. cyanescens. A combination of morphological and molecular methods enabled accurate identification of N. asiatica. This is the first study using DNA barcode to identify N. asiatica and the obtained DNA sequences will be added to the DNA barcode database. 

Description of a new eelpout Pachycara angeloi sp. nov. (Perciformes: Zoarcidae) from deep-sea hydrothermal vent fields in the Indian Ocean

Zootaxa ◽  
2021 ◽  
Vol 4980 (1) ◽  
pp. 99-112
Author(s):  
RALF THIEL ◽  
THOMAS KNEBELSBERGER ◽  
TERUE KIHARA ◽  
KLAAS GERDES
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Dna Sequences ◽  
Sequence Divergence ◽  
Coi Gene ◽  
Mitochondrial Coi ◽  
Dorsal Fin ◽  
Fin Rays ◽  
Specific Variation ◽  
The Indian Ocean

A new species of eelpout genus Pachycara Zugmayer, 1911 is described based on five specimens caught at a depth of 2419–3275 m along the Central and Southeast Indian Ridges in the Indian Ocean. The specimens were collected during the INDEX cruises in 2016, 2018 and 2019, respectively. The new species is distinguished from its congeners by the following combination of characters: scales and pelvic fins absent; lateral line configuration mediolateral; dorsal fin origin associated with vertebrae 7–9 with no free predorsal pterygiophores; vertebrae 27–28 + 57–59 = 85–87; dorsal-fin rays 78–80, anal-fin rays 58–62; pectoral fin rays 13–15. DNA sequences of a mitochondrial COI gene fragment showed low intra-specific variation ranging from 0–0.3 % sequence divergence and do not reflect different vent sites. This is the 29th species of Pachycara, which is the fifth to be described from specimens collected only from chemosynthetic environments and the sixth known from the Indian Ocean. 

Combining Nuclear and Mitochondrial Loci Provides Phylogenetic Information in the Philopterus Complex of Lice (Psocodea: Ischnocera: Philopteridae)

2020 ◽  
Author(s):  
Tomas Najer ◽  
Ivo Papousek ◽  
Oldrich Sychra ◽  
Andrew D Sweet ◽  
Kevin P Johnson
Keyword(s):  
Genetic Variation ◽  
Phylogenetic Trees ◽  
Sequence Divergence ◽  
Nuclear Genes ◽  
Morphological Data ◽  
Coi Gene ◽  
Phylogenetic Information ◽  
Mitochondrial Coi ◽  
Putative Species ◽  
Mitochondrial Loci

Abstract The Philopterus Complex includes several lineages of lice that occur on birds. The complex includes the genera Philopterus (Nitzsch, 1818; Psocodea: Philopteridae), Philopteroides (Mey, 2004; Psocodea: Philopteridae), and many other lineages that have sometimes been regarded as separate genera. Only a few studies have investigated the phylogeny of this complex, all of which are based on morphological data. Here we evaluate the utility of nuclear and mitochondrial loci for recovering the phylogeny within this group. We obtained phylogenetic trees from 39 samples of the Philopterus Complex (Psocodea: Philopteridae), using sequences of two nuclear (hyp and TMEDE6) and one mitochondrial (COI) marker. We evaluated trees derived from these genes individually as well as from concatenated sequences. All trees show 20 clearly demarcated taxa (i.e., putative species) divided into five well-supported clades. Percent sequence divergence between putative species (~5–30%) for the COI gene tended to be much higher than those for the nuclear genes (~1–15%), as expected. In cases where species are described, the lineages identified based on molecular divergence correspond to morphologically defined species. In some cases, species that are host generalists exhibit additional underlying genetic variation and such cases need to be explored by further future taxonomic revisions of the Philopterus Complex.

scholarly journals Phylogenetic Relationship of Indonesian Water Yam (Dioscorea alata L.) Cultivars Based on DNA Marker Using ITS-rDNA Analysis

2017 ◽  
Vol 9 (2) ◽  
pp. 154
Author(s):  
Purnomo Purnomo ◽  
Budi Setiadi Daryono ◽  
Hironobu Shiwachi
Keyword(s):  
Phylogenetic Relationship ◽  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Morphological Characters ◽  
Its Rdna ◽  
28S Rdna ◽  
Dioscorea Alata ◽  
Cultivar Groups ◽  
Pcr Products ◽  
Water Yam

Research on genetic diversity and intra-species classification of Indonesian Dioscorea alata L. based on morphological characters has been done, and the result shows that there are 4 sub-groups of green cultivars group, and 5 sub-groups of purplish-red cultivars group. The objectives of this study are to determine the phylogenetic relationship cultivars of D. alata Indonesia compared to D. bulbifera as nearest species as well as 3 cultivars from GenBank. The young leaves of 18 water yam cultivar accessions were collected from Java, Madura, South Sumatera, South Kalimantan, Centre Celebes (Sulawesi), Ternate, West Papua, and Nusa Tenggara islands of Indonesia. DNA Isolation was conducted using Phytopure reagent. DNA amplification was conducted using thermocycler, predenaturation at 95 oC 5 minutes, denaturation at 95 oC 1 minutes, annealing at 60 oC 3 minutes, and elongation at 72 oC 2 minutes along with 30 cycles. The PCR products were electrophoresed in 1.5% agarose and visualized under UV transiluminator. Fifty-five µl of PCR products with positive targeted band between 700-800 bp were sent to 1st Base Singapore for purification and sequencing of 18S, ITS-1, 5.8S, ITS-2, and 28S rDNA. The DNA sequences were compared and aligned by BioEdit program (version 7.0.5.2) and MEGA programs. Comparison of entire sequences of the tested samples were aligned by software ClustalW (version 1.83). Phylogenetic trees were based on hierarchical clustering of the alignments of 18S, ITS-1, 5.8S, ITS-2, and 28S rDNA and produced by Neigbor-Joining using MEGA 5 software of the bootstrap values (1000 replicates). The study result shows that D. alata cultivars have high genetic variability on ITS-1, 5.8S, and ITS-2 rDNA region. Groups of green and purplish red cultivars formed based on morphological characters are not formed based on ITS-rDNA markers. Sub-groups were formed based on ITS-rDNA molecular markers derived from both the green and purplish-red cultivar groups. This result revealed that two cultivar groups are not similar with RAPD and morphological characters.

Nucleotide polymorphisms in three genes support host and geographic speciation in tree pathogens belonging toGremmeniellaspp.

2002 ◽  
Vol 80 (11) ◽  
pp. 1151-1159 ◽  
Author(s):  
M Dusabenyagasani ◽  
G Laflamme ◽  
R C Hamelin
Keyword(s):  
North America ◽  
Dna Sequences ◽  
North American ◽  
Abies Balsamea ◽  
Host Specialization ◽  
Rrna Genes ◽  
Nucleotide Polymorphisms ◽  
Group I ◽  
Geographic Separation ◽  
Pinus Spp

We detected nucleotide polymorphisms within the genus Gremmeniella in DNA sequences of β-tubulin, glyceraldehyde phosphate dehydrogenase, and mitochondrial small subunit rRNA (mtSSU rRNA) genes. A group-I intron was present in strains originating from fir (Abies spp.) in the mtSSU rRNA locus. This intron in the mtSSU rRNA locus of strains isolated from Abies sachalinensis (Fridr. Schmidt) M.T. Mast in Asia was also found in strains isolated from Abies balsamea (L.) Mill. in North America. Phylogenetic analyses yielded trees that grouped strains by host of origin with strong branch support. Asian strains of Gremmeniella abietina (Lagerberg) Morelet var. abietina isolated from fir (A. sachalinensis) were more closely related to G. abietina var. balsamea from North America, which is found on spruce (Picea spp.) and balsam fir, and European and North American races of G. abietina var. abietina from pines (Pinus spp.) were distantly related. Likewise, North American isolates of Gremmeniella laricina (Ettinger) O. Petrini, L.E. Petrini, G. Laflamme, & G.B. Ouellette, a pathogen of larch, was more closely related to G. laricina from Europe than to G. abietina var. abietina from North America. These data suggest that host specialization might have been the leading evolutionary force shaping Gremmeniella spp., with geographic separation acting as a secondary factor.Key words: Gremmeniella, geographic separation, host specialization, mitochondrial rRNA, nuclear genes.

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