scholarly journals Pathogen inferred to have dispersed thousands of kilometres at sea, infecting multiple keystone kelp species

2021 ◽  
Vol 168 (4) ◽  
Author(s):  
Abigail L. Mabey ◽  
Elahe Parvizi ◽  
Ceridwen I. Fraser
Keyword(s):  
New Zealand ◽  
Phylogenetic Analyses ◽  
Disease Outbreaks ◽  
Marion Island ◽  
Brown Macroalgae ◽  
Ecosystem Responses ◽  
Durvillaea Antarctica ◽  
Close Relationship ◽  
Biodiversity And Ecosystem Function ◽  
Relationship Of

AbstractProtistan pathogens have been found to infect populations of some large brown macroalgae. Infection could reduce the ability of macroalgae to withstand hydrodynamic pressures through weakening tissues and reducing flexibility. Widespread mortality of macroalgae if disease outbreaks were to occur could have important flow-on consequences for biodiversity and ecosystem function. Recent discoveries of the protistan pathogen Maullinia infecting the ecologically keystone southern bull kelp Durvillaea in Chile, Australia, and on Marion Island, raise the possibility that this pathogen is dispersing across ocean basins with buoyant hosts. To determine whether Maullinia also infects southern bull kelp in New Zealand, samples of gall-like tissue from Durvillaea antarctica, D. poha, and D. willana were collected from intertidal sites, and genetic analyses (sequencing of partial 18S rRNA) carried out. Maullinia infections were detected in all three species of Durvillaea. Phylogenetic analyses show a close relationship of New Zealand Maullinia to M. braseltonii previously detected in Chile and on Marion Island. Based on its genetic similarity to distant lineages and its presence on buoyant hosts that have been shown to drift long distances at seas, we infer that Maullinia has dispersed across the Southern Ocean through rafting of infected bull kelp. Understanding the capacity of pathogens to disperse across oceans is critical part of forecasting and managing ecosystem responses to environmental change.

scholarly journals Linking morphological and molecular sources to disentangle the case of Xylodon australis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Javier Fernández-López ◽  
M. Teresa Telleria ◽  
Margarita Dueñas ◽  
Mara Laguna-Castro ◽  
Klaus Schliep ◽  
...  
Keyword(s):  
New Zealand ◽  
Phylogenetic Analyses ◽  
Single Species ◽  
R Package ◽  
Molecular Data ◽  
Historical Collections ◽  
Close Relationship ◽  
Kinship Relations ◽  
History Of ◽  
Different Sources

AbstractThe use of different sources of evidence has been recommended in order to conduct species delimitation analyses to solve taxonomic issues. In this study, we use a maximum likelihood framework to combine morphological and molecular traits to study the case of Xylodon australis (Hymenochaetales, Basidiomycota) using the locate.yeti function from the phytools R package. Xylodon australis has been considered a single species distributed across Australia, New Zealand and Patagonia. Multi-locus phylogenetic analyses were conducted to unmask the actual diversity under X. australis as well as the kinship relations respect their relatives. To assess the taxonomic position of each clade, locate.yeti function was used to locate in a molecular phylogeny the X. australis type material for which no molecular data was available using morphological continuous traits. Two different species were distinguished under the X. australis name, one from Australia–New Zealand and other from Patagonia. In addition, a close relationship with Xylodon lenis, a species from the South East of Asia, was confirmed for the Patagonian clade. We discuss the implications of our results for the biogeographical history of this genus and we evaluate the potential of this method to be used with historical collections for which molecular data is not available.

New aristonectine elasmosaurid plesiosaur specimens from the Early Maastrichtian of Angola and comments on paedomorphism in plesiosaurs

2015 ◽  
Vol 94 (1) ◽  
pp. 93-108 ◽  
Author(s):  
R. Araújo ◽  
M.J. Polcyn ◽  
J. Lindgren ◽  
L.L. Jacobs ◽  
A.S. Schulp ◽  
...  
Keyword(s):  
New Zealand ◽  
Histological Analysis ◽  
Phylogenetic Analyses ◽  
External Morphology ◽  
Sister Taxon ◽  
Close Relationship

AbstractNew elasmosaurid plesiosaur specimens are described from the Early Maastrichtian of Angola. Phylogenetic analyses reconstruct the Angolan taxon as an aristonectine elasmosaurid and the sister taxon of an unnamed form of similar age from New Zealand. Comparisons also indicate a close relationship with an unnamed form previously described from Patagonia. All of these specimens exhibit an ostensibly osteologically immature external morphology, but histological analysis of the Angolan material suggests an adult with paedomorphic traits. By extension, the similarity of the Angolan, New Zealand and Patagonian material indicates that these specimens represent a widespread paedomorphic yet unnamed taxon.

scholarly journals Investigation of the red algal parasites Rhodophyllis parasitica sp. nov. and Pterocladiophila hemisphaerica from New Zealand

2021 ◽  
Author(s):  
◽  
Maren Preuss
Keyword(s):  
Phylogenetic Analysis ◽  
New Zealand ◽  
Parasite Species ◽  
Nuclear Dna ◽  
Morphological Characteristics ◽  
Close Relationship ◽  
Red Algal ◽  
Different Origins ◽  
Relationship Of ◽  
The Relationship

<p>Red algal parasites are common within red algae and most parasites are closely related to their host. Red algal parasites can switch hosts and their development is unique. Red algal parasites are poorly known in New Zealand. There are only four parasites described in New Zealand and those are based on morphological characteristics. This thesis focuses on the two red algal parasites Rhodophyllis parasitica sp. nov. and Pterocladiophila hemisphaerica from New Zealand. First, development and phylogeny and distribution of an undescribed red algal parasite growing on Rhodophyllis membranacea was investigated. Microscopy, molecular markers (ITS2, cox1, cox2-3 spacer) and phylogenetic analysis, and herbarium sampling were used to address these questions. The parasite, described as Rhodophyllis parasitica sp. nov. shows a close relationship of all genomes to Rhodophyllis membranacea, which suggests that the parasite evolved from its hosts. The parasite is widely distributed throughout New Zealand. The second parasite, Pterocladiophila hemisphaerica was grouped taxonomically, based on morphology, in the order Gracilariales and parasitizes Pterocladia lucida in the order Gelidiales. Molecular marker were used to reveal the relationship of Pterocladiophila hemisphaerica to its host: if the parasite is grouped in the Gracilariales or the Gelidiales; if host switches might have occurred; and if atp8 is present in the parasite. Nuclear DNA (SSU rRNA, LSU rRNA), mitochondrial (cox1) and plastid regions (rbcL-rbcS spacer) from the parasite were sequenced and phylogenetic analysis performed. New primer were designed to amplify atp8 and genetic analysis performed. Pterocladiophila hemisphaerica evolved in the Florideophytes but neither in the Gracilariales or Gelidiales and the parasite possibly switched hosts at least two times, which was shown by three different origins of chloroplast, mitochondria and nuclear DNA. Atp8 in the parasite is present but probably a pseudogene. Rhodophyllis parasitica sp. nov. is the first described red algal parasite species in New Zealand in 55 years and Pterocladiophila hemisphaerica is the first parasite with organelles and nuclei with different histories of origin.</p>

Nodularia (Cyanobacteria, Nostocaceae): a phylogenetically uniform genus with variable phenotypes

Phytotaxa ◽  
2014 ◽  
Vol 172 (3) ◽  
pp. 235 ◽  
Author(s):  
Klára Řeháková ◽  
Jan Mareš ◽  
Alena Lukešová ◽  
Eliška Zapomělová ◽  
Kateřina Bernardová ◽  
...  
Keyword(s):  
Phenotypic Variability ◽  
Phylogenetic Analyses ◽  
Morphological Variability ◽  
Taxonomic Resolution ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Traditional System ◽  
Ecological Features ◽  
Close Relationship ◽  
Relationship Of

The taxonomy of cyanobacteria currently faces the challenge of overhauling the traditional system to better reflect the results of phylogenetic analyses. In the present study, we assessed the phylogenetic position, morphological variability, ability to produce the toxin nodularin, and source habitat of 17 benthic and soil isolates of Nodularia. A combined analysis of two loci (partial 16S rRNA gene and rbcLX region) confirmed the genus as a monophyletic unit and the close relationship of its members. However, the taxonomic resolution at the subgeneric level was extremely problematic. The phylogenetic clustering did not show any reasonable congruence with either morphological or ecological features commonly used to separate taxa in heterocytous cyanobacteria. Despite the near phylogenetic similarity of planktonic, benthic and soil Nodularia strains, we did not find any new nodularin-producing strains among the non-planktonic isolates. The relatively low variability in conserved molecular markers within the genus Nodularia exemplifies the limitations of the currently accepted taxonomic workflow and polyphasic approach. Elucidation of mechanisms that drive the phenotypic variability in such groups presents a major challenge in cyanobacterial research.

scholarly journals Phylogeny of the Hawkmoth Tribe Ambulycini (Lepidoptera: Sphingidae): Mitogenomes from Museum Specimens Resolve Major Relationships

2019 ◽  
Vol 3 (6) ◽  
Author(s):  
Martijn J T N Timmermans ◽  
Sainab M Daghmoumi ◽  
Deborah Glass ◽  
Chris A Hamilton ◽  
Akito Y Kawahara ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
New Caledonia ◽  
Phylogenetic Analyses ◽  
Long Distance ◽  
Tropical Asia ◽  
Biogeographic History ◽  
The Pacific ◽  
Close Relationship ◽  
Relationship Of ◽  
Dispersal Events

Abstract Ambulycini are a cosmopolitan tribe of the moth family Sphingidae, comprised of 10 genera, 3 of which are found in tropical Asia, 4 in the Neotropics, 1 in Africa, 1 in the Middle East, and 1 restricted to the islands of New Caledonia. Recent phylogenetic analyses of the tribe have yielded conflicting results, and some have suggested a close relationship of the monobasic New Caledonian genus CompsulyxHolloway, 1979 to the Neotropical ones, despite being found on opposite sides of the Pacific Ocean. Here, we investigate relationships within the tribe using full mitochondrial genomes, mainly derived from dry-pinned museum collections material. Mitogenomic data were obtained for 19 species representing nine of the 10 Ambulycini genera. Phylogenetic trees are in agreement with a tropical Asian origin for the tribe. Furthermore, results indicate that the Neotropical genus Adhemarius Oiticica Filho, 1939 is paraphyletic and support the notion that OrectaRothschild & Jordan 1903 and TrogolegnumRothschild & Jordan, 1903 may need to be synonymized. Finally, in our analysis the Neotropical genera do not collectively form a monophyletic group, due to a clade comprising the New Caledonian genus Compsulyx and the African genus BatocnemaRothschild & Jordan, 1903 being placed as sister to the Neotropical genus ProtambulyxRothschild & Jordan, 1903. This finding implies a complex biogeographic history and suggests the evolution of the tribe involved at least two long-distance dispersal events.

Endoconidioma populi from aspen and alder: phylogeny, and variations in cleistopycnidial morphology and their ecological implications

Botany ◽  
2010 ◽  
Vol 88 (7) ◽  
pp. 675-684 ◽  
Author(s):  
A. Tsuneda ◽  
S. Hambleton ◽  
R. S. Currah
Keyword(s):  
Phylogenetic Analyses ◽  
Basal Area ◽  
Internal Transcribed Spacers ◽  
Ecological Implications ◽  
Close Relationship ◽  
Dispersal Unit ◽  
Morphological Differences ◽  
The Individual ◽  
External Forces ◽  
Relationship Of

Cleistopycnidial ontogeny and sequences of nuclear internal transcribed spacers (ITS) and large subunits (LSU) were compared for five strains of Endoconidioma populi Tsuneda et al.: three from trembling aspen and two from alder. The cleistopycnidia of two of the aspen strains, including the type strain, were subglobose to flask-shaped (mostly 35–100 µm × 30–60 µm), and consisted solely of meristematic cells with thick cell walls that were heavily impregnated with melanin granules. Peridial cells were not visibly differentiated from locular cells and were also capable of forming endoconidia. Endoconidia were released from one to several sites of the cleistopycnidium by the dissolution of peridial cell wall. The alder strains shared these characteristics, except that their cleistopycnidia released both endoconidia and conidiogenous cells. Unlike those four strains, cleistopycnidia of the third aspen strain were cylindrical, often exceeding 500 µm in length, branched, and possessed a peridium of textura angularis that developed from short, determinate hyphae. Conidiogenous cells contained abundant lipid bodies that were not mobilized until the onset of endoconidiogenesis. The peridium at the basal area was prone to breakage by external forces, indicating that the individual cleistopycnidium, as a whole, functions as a dispersal unit. A small number of ITS nucleotide differences among strains corresponded to their observed morphological differences and host association. Phylogenetic analyses suggested a close relationship of E. populi with Hormonema carpetanum Bills, Peláez & Ruibal, and Coniozyma leucospermi (Crous & Denman) Crous.

Latronema whataitai sp. n. (Nematoda: Selachinematidae) from intertidal sediments of New Zealand, with notes on relationships within the family based on preliminary 18S and D2-D3 phylogenetic analyses

Nematology ◽  
2015 ◽  
Vol 17 (8) ◽  
pp. 941-952 ◽  
Author(s):  
Daniel Leduc ◽  
Zeng Zhao
Keyword(s):  
New Zealand ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Small Subunit ◽  
Rrna Genes ◽  
Intertidal Sediments ◽  
Molecular Sequences ◽  
Close Relationship ◽  
Central Tooth ◽  
Family Based

Latronema whataitai sp. n. is described from intertidal sediments of Hataitai Beach, North Island of New Zealand, and its placement within the Selachinematidae investigated using 18S and D2-D3 molecular sequences. Latronema whataitai sp. n. is characterised by relatively slender body (a = 22-25), outer labial setae and cephalic setae of similar length, anterior buccal cavity with three sets of seven teeth with larger central tooth positioned above the other six, circular amphid with faint outline, males with 12-13 precloacal supplements and spicules with pointed projection near distal end, and tail 2.0-2.6 anal body diam. long. The cuticle ultrastructure of the genus is investigated for the first time using scanning electron microscopy. Molecular phylogenies of near full length small subunit and D2-D3 expansion segments of the large subunit rRNA genes do not provide support for the division of Selachinematidae into the subfamilies Selachinematinae and Choniolaiminae, and do not support a close relationship between Latronema and Richtersia despite some morphological similarities. These preliminary results are based on a small number of molecular sequences, and therefore the current morphology-based classification remains the most tractable system for the Selachinematidae until more comprehensive analyses are conducted.

scholarly journals Genetic variability, cryptic species and phylogenetic relationship of six cyathostomin species based on mitochondrial and nuclear sequences

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mariana Louro ◽  
Tetiana A. Kuzmina ◽  
Christina M. Bredtmann ◽  
Irina Diekmann ◽  
Luís M. Madeira de Carvalho ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Host Species ◽  
Phylogenetic Analyses ◽  
Intestinal Nematode ◽  
Mitochondrial Haplotypes ◽  
Nematode Parasites ◽  
Close Relationship ◽  
Geographic Regions ◽  
Second Internal Transcribed Spacer ◽  
Relationship Of

AbstractCyathostomins are important intestinal nematode parasites of equines and include 50 accepted species. Their taxonomy has been frequently revised and the presence of cryptic species suggested. Furthermore, usually molecular- and morphology-based phylogenetic analyses give divergent results. In this study, the nucleotide sequences of the nuclear second internal transcribed spacer (ITS-2) and the mitochondrial partial cytochrome c oxidase subunit I (COI) were determined for adults of six cyathostomin species (Coronocyclus coronatus, Coronocyclus labiatus, Cylicocyclus nassatus, Cylicostephanus calicatus, Cylicostephanus longibursatus, Cylicostephanus minutus) collected from different equine species within two geographic regions. Maximum likelihood trees were calculated for ITS-2, COI, and concatenated data. No obvious differentiation was observed between geographic regions or equine host species. As previously reported, Coronocyclus coronatus and Cylicostephanus calicatus revealed a close relationship. Cryptic species were detected in Cylicostephanus minutus and Cylicostephanus calicatus. Cylicocyclus nassatus and Coronocyclus labiatus showed diverse mitochondrial and nuclear haplotypes occurring in different combinations, while Cylicostephanus longibursatus was comparatively homogenous. In conclusion, a combined analysis of nuclear and mitochondrial haplotypes improved resolution of the phylogeny and should be applied to the remaining cyathostomin species and across additional equine host species and geographic regions.

scholarly journals Chayote mosaic virus, a New Tymovirus Infecting Cucurbitaceae

2000 ◽  
Vol 90 (10) ◽  
pp. 1098-1104 ◽  
Author(s):  
Juan J. Bernal ◽  
Ignacio Jiménez ◽  
Manuel Moreno ◽  
Melanie Hord ◽  
Carmen Rivera ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Protein Gene ◽  
Phylogenetic Analyses ◽  
Disease Symptoms ◽  
Close Relationship ◽  
Andean Potato ◽  
The Caribbean ◽  
Asymptomatic Infections ◽  
Relationship Of ◽  
Host Families

Chayote mosaic virus (ChMV) is a putative tymovirus isolated from chayote crops in Costa Rica. ChMV was characterized at the host range, serological, and molecular levels. ChMV was transmitted mechanically and induced disease symptoms mainly in Cucurbitaceae hosts. Asymptomatic infections were detected in other host families. Serologically, ChMV is related to the Andean potato latent virus (APLV) and the Eggplant mosaic virus (EMV), both members of the genus Tymovirus infecting solanaceous hosts in the Caribbean Basin and South America. The sequence of the genomic RNA of ChMV was determined and its genetic organization was typical of tymoviruses. Comparisons with other tymoviral sequences showed that ChMV was a new member of the genus Tymovirus. The phylogenetic analyses of the coat protein gene were consistent with serological comparisons and positioned ChMV within a cluster of tymoviruses infecting mainly cucurbit or solanaceous hosts, including APLV and EMV. Phylogenetic analyses of the replicase protein gene confirmed the close relationship of ChMV and EMV. Our results suggest that ChMV is related to two tymoviruses (APLV and EMV) of proximal geographical provenance but with different natural host ranges. ChMV is the first cucurbit-infecting tymovirus to be fully characterized at the genomic level.

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