Search results for "Gnathostoma"
showing 7 items of 7 documents
Categorical versus geometric morphometric approaches to characterizing the evolution of morphological disparity in Osteostraci (Vertebrata, stem Gnat…
2020
Morphological variation (disparity) tends to be evaluated through two non-mutually exclusive approaches: (i) quantitatively, through geometric morphometrics, and (ii) in terms of discrete, ‘cladistic’, or categorical characters. Uncertainty over the comparability of these approaches diminishes the potential to obtain nomothetic insights into the evolution of morphological disparity, and the few benchmarking studies conducted so far show contrasting results. Here, we apply both approaches to characterising morphology in the stem-gnathostome vertebrate clade Osteostraci, in order to assess congruence between these alternative methods as well as to explore the evolutionary patterns of the grou…
Association between urticaria and nematode infections
2018
Background The association between parasites and urticaria was first suggested in the last century. A wide range, 0-75.4%, of the prevalence of parasitic infection has been reported with chronic urticaria (CU). Moreover, urticaria may be detected in patients with parasitosis. Nematodes are a type of helminth that infect hundreds of millions of people throughout the world. Objective The aim of this work was to collect and review the published studies and cases of urticaria associated with nematode infections. Methods A search of scientific literature data bases from January 1960 until May 2017 was carried out. Results Numerous nematode infections have been associated with urticaria and/or an…
Sequence, evolution and tissue expression patterns of an epidermal type I keratin from the shark Scyliorhinus stellaris.
2004
From the shark Scyliorhinus stellaris we cloned and sequenced a cDNA encoding a novel type I keratin, termed SstK10. By MALDI-MS peptide mass fingerprinting of cytoskeletal proteins separated on polyacrylamide gels, we assigned SstK10 to a 46-kDa protein which is the major epidermal type I (“IE”) keratin in this fish and is specifically expressed in stratified epithelia. In a phylogenetic tree based on type I keratin sequences and with lamprey keratins applied as outgroup, SstK10 branches off in a rather basal position. This tree strongly supports the concept that teleost keratins and tetrapod keratins resulted from two independent gene radiation processes. The only exception is human K18 b…
ITS-2 rDNA sequencing of Gnathostoma species (Nematoda) and elucidation of the species causing human gnathostomiasis in the Americas.
2000
From several gnathostome species the complete internal transcribed spacer ITS-2 ribosomal DNA (rDNA) repeat sequence and a fragment of the 5.8S rDNA were obtained by direct polymerase chain reaction cycle-sequencing and silver-staining methods. The size of the complete ITS-1 sequence in agarose gel electrophoresis was also obtained. The ITS-2 enabled the differentiation of Gnathostoma spinigerum from Thailand and Gnathostoma binucleatum from Mexico and Ecuador and confirmed the validity of the latter. Gnathostoma turgidum, Gnathostoma sp. I (=Gnathostoma procyonis sensu Almeyda-Artigas et al., 1994), and Gnathostoma sp. II (=G. turgidum sensu Foster, 1939 pro parte), all from Mexico, proved…
A new species of the genus Spiroxys (Nematoda: Gnathostomatidae) from Madagascan pleurodiran turtles (Pelomedusidae)
2008
AbstractSpiroxys ankarafantsika, sp. nov. is described from Madagascar in two species of freshwater turtles, Pelusios castanoides and Pelomedusa subrufa. Spiroxys ankarafantsika differs from other species of the genus in having pseudolabial teeth only on the median lobes and no other cuticular prominences, a smooth cuticular collar, deirides as cervical minute spine-like projections, and a gubernaculum without tubes. This is the first record of a nominal species of the genus Spiroxys from the Ethiopian region.
The Globin Gene Repertoire of Lampreys: Convergent Evolution of Hemoglobin and Myoglobin in Jawed and Jawless Vertebrates
2014
Agnathans (jawless vertebrates) occupy a key phylogenetic position for illuminating the evolution of vertebrate anatomy and physiology. Evaluation of the agnathan globin gene repertoire can thus aid efforts to reconstruct the origin and evolution of the globin genes of vertebrates, a superfamily that includes the well-known model proteins hemoglobin and myoglobin. Here, we report a comprehensive analysis of the genome of the sea lamprey (Petromyzon marinus )w hich revealed 23 intact globin genes and two hemoglobin pseudogenes. Analyses of the genome of the Arctic lamprey (Lethenteron camtschaticum) identified 18 full length and five partial globin gene sequences. The majority of the globin …
Notes on selected Cretaceous echinoids from south-central Sakhalin, Far East Russia
2013
AbstractFrom Albian, Santonian and Campanian strata in south-central Sakhalin, four echinoid taxa are described, illustrated and discussed. In Far East Russia, echinoids are rare constituents amongst mid- and Late Cretaceous macrofaunal assemblages in which inoceramid and non-inoceramid bivalves, plus heteromorph and non-heteromorph ammonites predominate. The sole regular species in the present lot is represented by an incomplete external mould of a primary spine of a rhabdocidarid,Polycidaris(?) sp., from the lower Campanian. Irregular taxa include a fragmentary, specifically indeterminate ‘pygurid’,Echinopygus(?) sp., of late Albian age, as well as two spatangoids. One of these, a toxaste…