Evolutionary relationships in Oxytropis species, as estimated from the nuclear ribosomal internal transcribed spacer (ITS) sequences point to multiple expansions into the Arctic

Botany ◽  
2012 ◽  
Vol 90 (8) ◽  
pp. 770-779 ◽  
Author(s):  
Annie Archambault ◽  
Martina V. Strömvik
Keyword(s):  
North American ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Trees ◽  
Its Region ◽  
Its Sequences ◽  
The Arctic ◽  
Evolutionary Relationships ◽  
Data Set ◽  
The North ◽  
North American Arctic

Species of the genus Oxytropis are distributed in the northern hemisphere, especially in alpine and arctic areas. Although comprehensive taxonomic treatments exist for local floras, an understanding of the evolutionary relationships is lacking for the genus as a whole. To determine if different ancestral Oxytropis species colonized the North American Arctic separately, as suggested by taxonomy, we sequenced the nuclear ribosomal internal transcribed spacer (ITS) region from 16 Oxytropis specimens, including four species that were used in a previous transcriptome study. In addition, 81 other Oxytropis ITS sequences were retrieved from public sequence databases and included in the analysis. The whole data set was analyzed using phylogenetic trees and statistical parsimony networks. Results show that all Oxytropis ITS sequences are very similar. Furthermore, at least six lineages evolved from different temperate ancestors to colonize the North American Arctic. This pattern is believed to be typical of the arctic flora. Additionally, the sequence relationship analyses confirm that the subgenus Phacoxytropis may be ancestral in Oxytropis.

Phylogeny of Braya and Neotorularia (Brassicaceae) based on nuclear ribosomal internal transcribed spacer and chloroplast trnL intron sequences

2004 ◽  
Vol 82 (3) ◽  
pp. 376-392 ◽  
Author(s):  
Suzanne I Warwick ◽  
Ihsan A Al-Shehbaz ◽  
Connie Sauder ◽  
James G Harris ◽  
Marcus Koch
Keyword(s):  
North American ◽  
Maximum Parsimony ◽  
Internal Transcribed Spacer ◽  
Sequence Data ◽  
Its Region ◽  
Molecular Data ◽  
Its Sequences ◽  
Evolutionary Relationships ◽  
Trnl Intron ◽  
The North

Sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region and the chloroplast trnL intron were used to examine the evolutionary relationships and generic delimitations of Braya, Neotorularia, Dichasianthus, and Sisymbriopsis. Several species, especially the North American - Asian Braya (= Neotorularia) humilis (C.A. Mey.) B.L. Rob., were previously assigned to more than one genus. Sequence data were obtained from all Braya species, except Braya pilosa Hook., seven species of Neotorularia, one of Dichasianthus, and two of Sisymbriopsis. Maximum parsimony analyses showed a poly phyletic origin for Neotorularia, with the genus split into three or four major clades. For both the ITS and trnL sequence data, three species (Neotorularia brachycarpa (Vassilcz.) Hedge & J. Léonard, Neotorularia gamosepala (Hedge) O'Kane & Al-Shehbaz, and Neotorularia humilis (C.A. Mey.) Hedge & J. Léonard) fell within the Braya clade; Neotorularia korolkowii (Regel & Schmalh.) Hedge & J. Léonard formed a separate clade with Dichasianthus subtilissimus (Popov) Ovcz. & Yunussov, while Neotorularia torulosa (Desf.) Hedge & J. Léonard, Neotorularia contor tuplicata (Stephan ex Willd.) Hedge & J. Léonard, Neotorularia dentata (Freyn & Sint.) Hedge & J. Léonard, and Neotorularia tetracmoides (Boiss. & Hausskn.) Hedge & J. Léonard formed either one clade (trnL data) or two clades (ITS data). Sisymbriopsis was not monophyletic, although ITS and trnL data showed a weakly supported relationship between Sisymbriopsis mollipila (Maxim.) Botsch. and one of the Neotorularia clades. Except for Braya forrestii W.W. Sm., which is well supported as sister to the remainder of the Braya clade (ITS data), ITS and trnL sequences showed poor resolution within Braya. Additive ITS sequences indicated allopolyploid origins for Braya fernaldii Abbe, Braya longii Fernald, and three accessions of Braya glabella Richardson (all species with 2n = 56). Morphology and molecular data strongly suggest expanding Braya to include N. humilis, N. brachycarpa, and N. gamosepala; delimiting Neotorularia to include N. torulosa, N. contortuplicata, N. dentata, N. korolkowii, N. tetracmoides, D. subtilissimus, and S. mollipila; and revising Sisymbriopsis.Key words: Braya, Neotorularia, Dichasianthus, Sisymbriopsis, ITS, trnL, Brassicaceae.

Phylogenetic relationships of the monogenomic species of the wheat tribe, Triticeae (Poaceae), inferred from nuclear rDNA (internal transcribed spacer) sequences

Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 211-223 ◽  
Author(s):  
C. Hsiao ◽  
N. J. Chatterton ◽  
K. H. Asay ◽  
K. B. Jensen
Keyword(s):  
Phylogenetic Relationships ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Trees ◽  
Parallel Evolution ◽  
Diploid Species ◽  
Its Region ◽  
Molecular Data ◽  
Nuclear Ribosomal Dna ◽  
The Arctic ◽  
Cytogenetic Evidence

Phylogenetic relationships of 30 diploid species of Triticeae (Poaceae) representing 19 genomes were estimated from the sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The ITS sequence phylogeny indicated that: (i) each genome group of species is monophyletic, concordant with cytogenetic evidence; (ii) Hordeum (I) and Critesion (H) are basal; (iii) Australopyrum (W) is closely related to Agropyron (P); (iv) Peridictyon (G), Heteranthelium (Q), and Dasypyrum (V) are closely related to Pseudoroegneria (S); (v) most of the annuals, Triticum s.l. (A, B, D), Crithopsis (K), Taeniatherum (T), Eremopyrum (F), Henrardia (O), Secale (R), and two perennials, Thinopyrum (J) and Lophopyrum (E), all of Mediterranean origin, are a monophyletic group. However, phylogenetic trees based on morphology group these Mediteranean species with various perennial lineages of the Arctic-temperate region. The molecular data and biogeography of the tribe suggest that the Mediterranean lineage is derived from the Arctic-temperate lineage and that the two lineages have evolved in parallel. Extensive morphological parallelism apparently obscures the true genealogical history of the tribe when only morphology is considered.Key words: Poaceae, Triticeae, rDNA sequence, molecular phylogeny, parallel evolution.

The Arctic Institute of North America

Polar Record ◽  
1956 ◽  
Vol 8 (52) ◽  
pp. 22-23 ◽  
Author(s):  
P. D. Baird
Keyword(s):  
North America ◽  
North American ◽  
Scientific Research ◽  
The Arctic ◽  
The North ◽  
Reference Information ◽  
North American Arctic ◽  
Mcgill University

The Arctic Institute of North America was established in 1945 in two small rooms in McGill University, with a staff consisting of Dr Lincoln Washburn and a secretary, who made up for the lack of equipment and facilities by abundant energy and enthusiasm. Since then the Institute's growth has been considerable, always in the direction of its three main objectives—to form a centre for reference information and study on the North American Arctic, to encourage arctic scientific research in any field, and to disseminate arctic information by means of a journal, other publications, and lectures.

scholarly journals The Oxford Handbook of the Prehistoric Arctic

2016 ◽  
Keyword(s):  
North American ◽  
Full Range ◽  
Limited Range ◽  
Great Accuracy ◽  
The Arctic ◽  
Stone Tool ◽  
Cultural Tradition ◽  
Cold Temperatures ◽  
The North ◽  
North American Arctic

The North American Arctic was one of the last regions on Earth to be settled by humans, due to its extreme climate, limited range of resources, and remoteness from populated areas. Despite these factors, it holds a rich and complex history relating to Inuit, Iñupiat, Inuvialuit, Yupik, and Aleut peoples and their ancestors. The artifacts, dwellings, and food remains of these ancient peoples are remarkably well preserved due to cold temperatures and permafrost, allowing archaeologists to reconstruct their lifeways with great accuracy. Furthermore, the combination of modern Elders’ traditional knowledge with the region’s high-resolution ethnographic record allows past peoples’ lives to be reconstructed to a level simply not possible elsewhere. Combined, these factors yield an archaeological record of global significance—the Arctic provides ideal case studies relating to issues as diverse as the impacts of climate change on human societies, the complex process of interaction between indigenous peoples and Europeans, and the dynamic relationships between environment, economy, social organization, and ideology in hunter-gatherer societies. In this book, each Arctic cultural tradition is described in detail, with up-to-date coverage of recent interpretations of all aspects of their lifeways. Additional chapters cover broad themes applicable to the full range of arctic cultures, such as trade, stone tool technology, ancient DNA research, and the relationship between archaeology and modern arctic communities. The resulting volume, written by the region’s leading researchers, is by far the most comprehensive coverage of North American arctic archaeology ever assembled.

scholarly journals Timing of Breeding Site Availability Across the North-American Arctic Partly Determines Spring Migration Schedule in a Long-Distance Neotropical Migrant

2021 ◽  
Vol 9 ◽  
Author(s):  
Jean-François Lamarre ◽  
Gilles Gauthier ◽  
Richard B. Lanctot ◽  
Sarah T. Saalfeld ◽  
Oliver P. Love ◽  
...  
Keyword(s):  
North American ◽  
Breeding Site ◽  
The Arctic ◽  
Timing Of Breeding ◽  
Long Distance ◽  
Breeding Sites ◽  
The North ◽  
North American Arctic ◽  
Departure Date ◽  
Breeding Location

Long-distance migrants are under strong selection to arrive on their breeding grounds at a time that maximizes fitness. Many arctic birds start nesting shortly after snow recedes from their breeding sites and timing of snowmelt can vary substantially over the breeding range of widespread species. We tested the hypothesis that migration schedules of individuals co-occurring at the same non-breeding areas are adapted to average local environmental conditions encountered at their specific and distant Arctic breeding locations. We predicted that timing of breeding site availability (measured here as the average snow-free date) should explain individual variation in departure time from shared non-breeding areas. We tested our prediction by tracking American Golden-Plovers (Pluvialis dominica) nesting across the North-American Arctic. These plovers use a non-breeding (wintering) area in South America and share a spring stopover area in the nearctic temperate grasslands, located >1,800 km away from their nesting locations. As plovers co-occur at the same non-breeding areas but use breeding sites segregated by latitude and longitude, we could disentangle the potential confounding effects of migration distance and timing of breeding site availability on individual migration schedule. As predicted, departure date of individuals stopping-over in sympatry was positively related to the average snow-free date at their respective breeding location, which was also related to individual onset of incubation. Departure date from the shared stopover area was not explained by the distance between the stopover and the breeding location, nor by the stopover duration of individuals. This strongly suggests that plover migration schedule is adapted to and driven by the timing of breeding site availability per se. The proximate mechanism underlying the variable migration schedule of individuals is unknown and may result from genetic differences or individual learning. Temperatures are currently changing at different speeds across the Arctic and this likely generates substantial heterogeneity in the strength of selection pressure on migratory schedule of arctic birds migrating sympatrically.

scholarly journals A Benchmark for Trace Greenhouse Gases in the Arctic Ocean

Eos ◽  
2017 ◽  
Author(s):  
Terri Cook
Keyword(s):  
Nitrous Oxide ◽  
Greenhouse Gases ◽  
Arctic Ocean ◽  
North American ◽  
The Arctic ◽  
The North ◽  
The Arctic Ocean ◽  
North American Arctic

Samples of seawater from the North American Arctic show that the region is neither a major source nor sink of methane and nitrous oxide to the overlying atmosphere.

Phylogeny of Gremmeniella spp. based on sequences of the 5.8S rDNA and internal transcribed spacer region

1997 ◽  
Vol 75 (5) ◽  
pp. 693-698 ◽  
Author(s):  
Richard C. Hamelin ◽  
Jimmy Rail
Keyword(s):  
North American ◽  
Internal Transcribed Spacer ◽  
Host Specialization ◽  
Evolutionary Relationships ◽  
Abies Sachalinensis ◽  
Internal Transcribed Spacer Region ◽  
5.8S Rdna ◽  
Asian Race ◽  
The North ◽  
Distance Methods

Sequences in the 5.8S rDNA and internal transcribed spacer region were obtained for taxa belonging to Gremmeniella spp., and a phylogenetic analysis was carried out using parsimony and distance methods. A set of hypotheses concerning evolutionary relationships between members of that genus was tested. The hypothesis that all members of Gremmeniella abietina var. abietina are closely related was rejected. It appears that the Asian race is quite divergent from the European and North American races, but could be more closely related to G. abietina var. balsamea. The phylogeny was consistent with host specificity: members of G. abietina var. abietina generally do not infect Abies or Picea spp. but the Asian race occurs on Abies sachalinensis in Japan. The hypothesis that host specialization has created divergence within G. abietina var. balsamea was supported by our analysis because the levels of divergence between isolates originating from Picea spp. and Abies spp. were similar to those found between the North American and European races of G. abietina var. abietina. The hypothesis that greater divergence occurred between Gremmeniella abietina and Gremmeniella laricina than between G. abietina var. abietina and G. abietina var. balsamea was not supported. The level of divergence was as large between the two varieties within G. abietina as between the two species G. abietina and G. laricina. These results indicate that similar taxonomic levels should be applied to these three taxa. Key words: scleroderris canker, internal transcribed spacer (ITS).

scholarly journals Genetic diversity and biogeography in Chaetomorpha melagonium (Ulvophyceae, Cladophorales) based on internal transcribed spacer (ITS rDNA) sequences

2020 ◽  
Author(s):  
C Boedeker ◽  
F Leliaert ◽  
Giuseppe Zuccarello
Keyword(s):  
Genetic Diversity ◽  
Dna Sequences ◽  
Base Pair ◽  
Internal Transcribed Spacer ◽  
Large Subunit ◽  
Point Mutations ◽  
Its Sequences ◽  
The Arctic ◽  
Lsu Rdna ◽  
The North

© 2017 Walter de Gruyter GmbH, Berlin/Boston. Chaetomorpha melagonium is a morphologically distinct species of green algae that occurs throughout the North Atlantic, the North Pacific and the Arctic Ocean. In this study, we analyzed the intraspecific genetic diversity among 14 samples of C. melagonium from across the distribution range based on nuclear large subunit ribosomal DNA (LSU rDNA) and rDNA internal transcribed spacer (ITS) DNA sequences. All samples had identical LSU sequences. The ITS sequences had very few mutations that nevertheless divided the specimens into two groups: one included samples from Iceland, Svalbard, Massachusetts and Alaska with identical ITS sequences; members of this group differed in samples from Europe (France, Germany, Scotland, Sweden, and Wales) by three mutations (two point mutations and one five base pair indel). The European specimens had identical ITS sequences with the exception of a single sample from Brittany that differed by one base pair. The maximum ITS sequence divergence within the samples of C. melagonium was less than 0.5%. This low intraspecific variation in the frequently used highly variable ITS region is discussed in the context of past geological and climatic scenarios.

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