Genetic variation within species of the nematode genus Cloacina (Strongyloidea:Cloacininae) parasitic in the stomachs of rock wallabies, Petrogale spp. (Marsupialia:Macropodidae) in Queensland

2009 ◽  
Vol 57 (1) ◽  
pp. 1 ◽  
Author(s):  
Neil B. Chilton ◽  
Florence Huby-Chilton ◽  
Peter M. Johnson ◽  
Ian Beveridge ◽  
Robin B. Gasser

Four morphospecies of Cloacina, parasitic nematodes in the stomachs of rock wallabies (Petrogale spp.) from Queensland, were compared genetically using sequence data of the two internal transcribed spacers of nuclear ribosomal DNA (rDNA). The results suggest that two geographically isolated populations of C. ernabella from P. purpureicollis were genetically distinct. Based on the autapomorphic species concept, these two C. ernabella populations represented different species. For the three other nematode morphospecies, there were genetic differences among individuals of a morphospecies present in different species of host. The results suggest that each may represent a complex of sibling species, with a different species present in each species of rock wallaby examined for that morphospecies. In the C. caenis and C. pearsoni complexes, the lineage present in P. purpureicollis from western Queensland represents a sister taxon to those in the P. pencillata complex from the east coast. In the C. robertsi complex, the taxon parasitic in P. persephone represents the sister taxon to those in the P. pencillata complex and in P. purpureicollis. C. robertsi was found for the first time in P. purpureicollis from Winton in central Queensland, suggesting contact in the recent past between populations of P. purpureicollis and a member of the P. penicillata complex.

1998 ◽  
Vol 11 (4) ◽  
pp. 321 ◽  
Author(s):  
Austin R. Mast

Despite considerable research interest in the subtribe Banksiinae (Banksia L.f. and Dryandra R.Br.), no strongly supported phylogenetic hypothesis for the relationship between the genera exists, nor have molecular characters been sampled for phylogenetic reconstruction at any level. In this study, DNA sequence characters were sampled from chloroplast DNA (cpDNA; the trnL intron, the trnL 3′ exon, and the spacer between the trnL 3′ exon and trnF) and nuclear ribosomal DNA (nrDNA; both internal transcribed spacers) of 18 species of Banksia and five of Dryandra, with six outgroup taxa from the subfamily Grevilleoideae. The molecular characters provided the opportunity to code taxa outside of Banksia for cladistic comparison with the genus—an opportunity not previously provided by morphological characters. Cladistic analyses, using parsimony, explored the effects of various weightings of transition to transversion events and base substitution to insertion and deletion events to determine which relationships in the cladograms were robust. The trnL/trnF and ITS characters strongly supported a paraphyletic Banksia with respect to a monophyletic Dryandra. The molecular results supported a single root for Thiele and Ladiges’(1996) unrooted morphological cladogram along the branch between the Isotylis to B. fuscolutea clade and the Grandes to B. tricuspis clade. George’s (1981) subgenus Banksia and section Banksia appeared dramatically non-monophyletic. The distribution of eastern taxa at derived positions on the molecular cladograms suggested considerable cladogenesis in the the genus prior to the formation of the Nullarbor Plain during the Tertiary.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Tanapan Sukee ◽  
Ian Beveridge ◽  
Anson V. Koehler ◽  
Ross Hall ◽  
Robin B. Gasser ◽  
...  

Abstract Background The subfamily Phascolostrongylinae (Superfamily Strongyloidea) comprises nematodes that are parasitic in the gastrointestinal tracts of macropodid (Family Macropodidae) and vombatid (Family Vombatidae) marsupials. Currently, nine genera and 20 species have been attributed to the subfamily Phascolostrongylinae. Previous studies using sequence data sets for the internal transcribed spacers (ITS) of nuclear ribosomal DNA showed conflicting topologies between the Phascolostrongylinae and related subfamilies. Therefore, the aim of this study was to validate the phylogenetic relationships within the Phascolostrongylinae and its relationship with the families Chabertiidae and Strongylidae using mitochondrial amino acid sequences. Methods The sequences of all 12 mitochondrial protein-coding genes were obtained by next-generation sequencing of individual adult nematodes (n = 8) representing members of the Phascolostrongylinae. These sequences were conceptually translated and the phylogenetic relationships within the Phascolostrongylinae and its relationship with the families Chabertiidae and Strongylidae were inferred from aligned, concatenated amino acid sequence data sets. Results Within the Phascolostrongylinae, the wombat-specific genera grouped separately from the genera occurring in macropods. Two of the phascolostrongyline tribes were monophyletic, including Phascolostrongylinea and Hypodontinea, whereas the tribe Macropostrongyloidinea was paraphyletic. The tribe Phascolostrongylinea occurring in wombats was closely related to Oesophagostomum spp., also from the family Chabertiidae, which formed a sister relationship with the Phascolostrongylinae. Conclusion The current phylogenetic relationship within the subfamily Phascolostrongylinae supports findings from a previous study based on ITS sequence data. This study contributes also to the understanding of the phylogenetic position of the subfamily Phascolostrongylinae within the Chabertiidae. Future studies investigating the relationships between the Phascolostrongylinae and Cloacininae from macropodid marsupials may advance our knowledge of the phylogeny of strongyloid nematodes in marsupials. Graphical Abstract


2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Francesco Rubino ◽  
Amalia Voukelatou ◽  
Francesca De Luca ◽  
Carla De Giorgi ◽  
Marcella Attimonelli

Plant-parasitic nematodes are important pests of crop plants worldwide, and also among the most difficult animals to identify. Their identification based on nuclear ribosomal DNA (rDNA) cistron (18S, 28S, and 5.8S RNA genes, and internal transcribed spacers, ITS1 and ITS2) is becoming a popular tool. Sequences from nuclear ribosomal RNA repeats have been used to demonstrate the identity of isolates from various hosts and to unravel the relationships of cryptic and complex species. In addition, the availability of RNA sequences allows study of phylogenetic relationships between nematodes, also for more complete understanding of their biology as agricultural pests. PPNEMA is a plant-parasitic nematode bioinformatic resource. It consists of a database of ribosomal cistron sequences from various species grouped according to nematode genera, and a search system allowing data to be extracted according to both text and pattern searching. PPNEMA offers to the scientific community a preprocessed archive of plant parasitic nematode sequences useful for nematologists. It is a tool to retrieve plant nematode multialigned sequences for phylogenetic studies or to recognize a nematode by comparing its rDNA sequence with the PPNEMA available genus specific multialignments.


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)


2002 ◽  
Vol 80 (9) ◽  
pp. 1002-1017 ◽  
Author(s):  
Suzanne I Warwick ◽  
Ihsan A Al-Shehbaz ◽  
Robert A Price ◽  
Connie Sauder

The genus Sisymbrium as currently circumscribed includes about 94 species disjunctly distributed in the Old (41 spp.) and the New World (53 spp.). Sisymbrium has been variously delimited, with several segregate genera proposed (subtribe Sisymbriinae) primarily for the new World taxa, including Schoenocrambe, Coelophragmus, and Mostacillastrum. Using sequence data from the internal transcribed spacers of nuclear ribosomal DNA and the 5.8S rRNA gene (collectively, ITS region), we examined the evolutionary relationships of Old and New World Sisymbrium species with its segregate genera and the validity of O.E. Schulz's classical sectional treatment of Sisymbrium. Sequence data were obtained from 33 Sisymbrium species, representing all 14 sections and two Sisymbrium species formerly assigned to segregate genera Coelophragmus and Mostacillastrum (subtribe Sisymbriinae), and two putative Sisymbrium species currently assigned to Neotorularia. Sequence data were also obtained from 26 taxa from segregate or related genera includingSchoenocrambe, Werdermannia (subtribe Sisymbriinae), eight genera in the Thelypodieae, Sibara (tribe Arabideae) and Pringlea (tribe Pringleeae), four members of the tribe Brassiceae, and three other Neotorularia species. Results from maximum parsimony analysis showed a polyphyletic origin for Sisymbrium and did not correspond well to Schulz's sectional classification. Sisymbrium species were split into three major clades: Old World Sisymbrium (including Neotorularia aculeolata, Neotorularia afghanica, and the type species of Schoenocrambe, Schoenocrambe linifolia, the sole New World member of this Old World clade); New World Sisymbrium (along with the remaining New World taxa) and designated as the New World Thelypodieae alliance; and the tribe Brassiceae ( including Sisymbrium supinum and Sisymbrium thellungii).Key words: Sisymbrium, Schoenocrambe, ITS, Thelypodieae, taxonomy, Brassicaceae.


Parasitology ◽  
2019 ◽  
Vol 146 (13) ◽  
pp. 1673-1682 ◽  
Author(s):  
Tanapan Sukee ◽  
Ian Beveridge ◽  
Neil B. Chilton ◽  
Abdul Jabbar

AbstractThe genetic variation and taxonomic status of the four morphologically-defined species of Macropostrongyloides in Australian macropodid and vombatid marsupials were examined using sequence data of the ITS+ region (=first and second internal transcribed spacers, and the 5.8S rRNA gene) of the nuclear ribosomal DNA. The results of the phylogenetic analyses revealed that Ma. baylisi was a species complex consisting of four genetically distinct groups, some of which are host-specific. In addition, Ma. lasiorhini in the common wombat (Vombatus ursinus) did not form a monophyletic clade with Ma. lasiorhini from the southern hairy-nosed wombat (Lasiorhinus latifrons), suggesting the possibility of cryptic (genetically distinct but morphologically similar) species. There was also some genetic divergence between Ma. dissimilis in swamp wallabies (Wallabia bicolor) from different geographical regions. In contrast, there was no genetic divergence among specimens of Ma. yamagutii across its broad geographical range or between host species (i.e. Macropus fuliginosus and M. giganteus). Macropostrongyloides dissimilis represented the sister taxon to Ma. baylisi, Ma. yamagutii and Ma. lasiorhini. Further morphological and molecular studies are required to assess the species complex of Ma. baylisi.


Parasitology ◽  
2007 ◽  
Vol 134 (7) ◽  
pp. 1041-1051 ◽  
Author(s):  
S. D'AMELIO ◽  
N. B. BARROS ◽  
S. INGROSSO ◽  
D. A. FAUQUIER ◽  
R. RUSSO ◽  
...  

SUMMARYSpecimens of Contracaecum spp. from Phalacrocorax auritus and Pelecanus occidentalis from Florida were characterized by sequencing of the small subunit of the mitochondrial ribosomal RNA gene (rrnS) and by PCR-based RFLP analysis of the same gene and of the internal transcribed spacers (ITS) of nuclear ribosomal DNA. Analyses of the rrnS sequence data using the MP and UPGMA approaches yielded trees with similar topologies, delineating 3 main clusters. Specimens from Ph. auritus, morphologically assigned to C. rudolphii (s.l.), were part of the cluster comprising also the other 2 species of the C. rudolphii complex (A and B), but representing a genetically distinct group, potentially corresponding to a distinct lineage within the complex, provisionally named as C. rudolphii C. The second cluster comprised 5 individuals from P. occidentalis, which formed a genetically relatively homogeneous group. The rrnS data indicate that these specimens (indicated as Contracaecum sp. 1) are clearly genetically different from the morphologically most closely related species, i.e. C. rudolphii (s.l.) and C. microcephalum, and could represent a new species. The third cluster comprised 7 specimens from P. occidentalis morphologically assigned to C. multipapillatum (s.l.). These were shown to be genetically homogeneous and related to but quite distinct from C. multipapillatum from Greece, although additional studies are needed to assess their status. PCR-RFLP based markers for the quick identification of these taxa are provided.


2012 ◽  
Vol 26 (2) ◽  
pp. 204 ◽  
Author(s):  
Shokoofeh Shamsi ◽  
Robin Gasser ◽  
Ian Beveridge

Three species of Anisakis from Australian marine mammals, including Anisakis brevispiculata, A. simplex C and A. pegreffii, are described and characterised genetically on the basis of sequence data for the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear rDNA. Parasite specimens were collected from Delphinus delphis, Tursiops truntatus and Kogia sima in Australia. A. brevispiculata is reported for the first time in Australia. However, analyses of sequence data suggests that A. brevispiculata in Australia is genetically distinct from specimens considered to represent the same species from other parts of the world. Fourth larval and adult stages of A. pegreffii were found in dolphins. Assigning larvae to A. pegreffii was based on the ITS-1 and ITS-2 sequences. A description of these larvae also is provided. Furthermore, fourth-stage larvae of A. simplex C were found in Kogia sima. Alignments of ITS-1 and ITS-2 sequences for members of A. simplex sensu lato revealed that nucleotide differences in ITS-1 can be used to differentiate among members of A. simplex sensu lato. This study reinforces the use of a combined molecular and morphological approach for the specific identification of anisakid nematodes.


2018 ◽  
Vol 93 (04) ◽  
pp. 486-493 ◽  
Author(s):  
N.B. Chilton ◽  
F. Huby-Chilton ◽  
A. Koehler ◽  
R.B. Gasser ◽  
I. Beveridge

AbstractThe phylogenetic relationships of 42 species of cloacinine nematodes belonging to three tribes (Coronostrongylinea, Macropostrongylinea and Zoniolaiminea) were examined based on sequence data of the first and second internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. All nematodes examined are parasites of Australian macropodid marsupials. None of the three nematode tribes was monophyletic. Paraphyly was also encountered in three genera: Papillostrongylus, Monilonema and Wallabinema. Species within the genus Thallostonema were limited to a single host genus (i.e. Thylogale), whereas species within the five principal genera (Coronostrongylus, Macropostrongylus, Popovastrongylus, Wallabinema and Zoniolaimus) were found to occur in multiple host genera. Potential modes of evolution among these nematodes are discussed.


1997 ◽  
Vol 75 (4) ◽  
pp. 519-532 ◽  
Author(s):  
Y. J. Liu ◽  
S. O. Rogers ◽  
Y. J. Liu ◽  
J. F. Ammirati

The genus Cortinarius Fr. (Cortinariaceae, Agaricales) is divided into four or more subgenera. Dermocybe (Fr.) Sacc. has been recognized as either a subgenus of Cortinarius or a separate genus, distinguished in part by the presence of various anthraquinonic pigments. Nucleotide sequences of ribosomal DNA 5.8S and internal transcribed spacers were used to investigate the phylogenetic relationships among species of Dermocybe and selected taxa from subgenera of Cortinarius. Sequence data from 47 herbarium specimens representing 31 taxa (28 species plus 3 varieties) of Dermocybe and Cortinarius were analyzed using parsimony, maximum likelihood, and neighbor joining. In general, molecular data support the morphological groupings of the taxa, although they more closely correspond to biochemical (anthraquinone and other) analyses. Phylogenetic trees showed that, while the sections Dermocybe and Malicoriae are monophyletic, and the concolorous or almost concolorous red species (section Sanguineae, such as D. sanguinea and relatives) together formed a coherent clade, the subgenus Dermocybe sensu lato itself is polyphyletic. Cortinarius californicus clusters with taxa in Cortinarius, subgenus Telamonia, section Armillati. Dermocybe olivaceopicta is more closely related to other subgenera of Cortinarius than to Dermocybe. Within the genus Cortinarius, certain of the subgenera may actually represent coherent genera. Of the subgenera examined, Telamonia, Phlegmacium, and possibly Sericeocybe appear to represent well defined taxonomic groupings. However, current assignments of taxa within Leprocybe and Myxacium were inconsistent with the molecular data. Reorganization of some taxa and taxonomic groups is suggested. Key words: Dermocybe, Cortinarius, molecular phylogeny, rDNA, ITS1, ITS2.


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