Tylenchid entomoparasites isolated from Spondylis buprestoides (L.) and Asemum striatum (L.) (Coleoptera: Cerambycidae)

Nematology ◽  
2016 ◽  
Vol 18 (7) ◽  
pp. 775-780 ◽  
Author(s):  
Natsumi Kanzaki ◽  
Robin M. Giblin-Davis ◽  
Rafael Gonzalez ◽  
Yasiel Trujillo ◽  
Ann E. Hajek

Tylenchid entomoparasites were isolated from two longhorn beetle species, Spondylis buprestoides from Tsukuba, Japan, and Asemum striatum from Ithaca, Tompkins County, NY, USA. Parasitic females and juveniles were obtained from S. buprestoides, where the female has a large body (5-6 mm long), clear stylet retracted into the body and degenerate anus and rectum, similar to some neotylenchids and allantonematids. By contrast, only stylet-bearing parasitic juveniles were found in eggs of A. striatum, and detailed morphological analysis was not done for this isolate. These two isolates of parasites were molecularly characterised, and analysed for their phylogenetic status based on the small subunit of the ribosomal RNA gene. The phylogenetic inference suggested that the two parasitic nematodes are close to each other, and to the siricidicola superspecies of the genus Deladenus, i.e., these two species and Deladenus form a well-supported clade. Because these two host beetle species belong to the same cerambycid subfamily (Spondylinae) from disparate locations, a subfamily-associated nematode parasite lineage may be revealed by further field surveys.

Nematology ◽  
2006 ◽  
Vol 8 (5) ◽  
pp. 739-747 ◽  
Author(s):  
Božena Koubková ◽  
Vlastimil Baruš ◽  
Iveta Matějusová ◽  
Iveta Hodová ◽  
Petr Koubek

Abstract Thelastoma gueyei sp. n., a nematode belonging to the long-tailed species group of the genusThelastoma, is described from the diplopodArchispirostreptus tumuliporus (Spirostreptidae) collected in Niokolo Koba National Park (Senegal, West Africa).Thelastoma gueyei sp. n. is morphologically most similar toT. gipetiti. Females are characterised by: the vulva being situated in the posterior half of the body and near to the anus (V′ = 75-86) with the anterior vulval lip developed into a prominent flap; excretory pore located at the level of the anterior end of the pharyngeal bulb; b′ = 28-38 and tail, expressed as a proportion of L′, = 1.7-2.7. Males have narrow cuticular alae extending from about the middle of the pharynx to the level of the anteriormost pair of copulatory papillae; four pairs of copulatory papillae, two large, subventral, pairs being located adcloacally on the genital cone, a third, much smaller pair on the posterior margin of the genital cone and the last pair being situated at the mid-point of the tail spike; and a tail occupying 10.8-13.2% of the total body length. The distal tip of the spicule is drop-shaped. Morphological characteristics were studied using scanning electron microscopy and a comparison of the long-tailed group of thelastomatids is provided. Nucleic acid sequence of the small subunit ribosomal RNA gene was obtained for purposes of DNA barcoding.


Nematology ◽  
2000 ◽  
Vol 2 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Paul De Ley ◽  
Mark Dorris ◽  
Mark Blaxter

AbstractThe parasitic Nematoda have traditionally been classified distinct from free-living species, and animal parasites treated separately from plant parasites. In classical concepts of phylogenetic relationships within the phylum, parasitic groups are usually afforded ordinal status and their origins are often obscure. We have been using molecular phylogenetics to examine the interrelationships of animal parasites with free-living and plant-parasitic groups, and find that a new view of the origins and radiation of animal parasites is warranted. Using sequence from the nuclear small subunit ribosomal RNA gene, we have constructed an alignment that allows robust phylogenetic inference. With this dataset, we place the Strongylida as a monophyletic clade nested within the Rhabditina. The Ascaridida, Oxyurida and Spirurida are closely related, but currently have no clear closest free-living sister taxon. Strongyloides spp. are rooted in a radiation of cephalobid/tylenchid species. Where available, other sequences in general confirm these relationships. Les Nematoda parasites ont été traditionnellement classifiés séparément des espèces libres, les parasites d’animaux étant traités séparément des parasites de plantes. Suivant les concepts classiques des relations phylogénétiques à l’intérieur du phylum, les groupes parasites sont habituellement traités au niveau ordinal et leurs origines sont souvent inconnues. Utilisant la phylogénie moléculaire, les interrelations des parasites animaux avec les groupes d’espèces libres et parasites de plantes ont été étudiées conduisant à la conclusion qu’une nouvelle approche des origines et de l’évolution des parasites animaux est nécessaire. Sur la base de la petite sous-unité nucléaire du gène de l’ARN ribosomal, un alignement est proposé qui permet une inférence phylogénétique solide. Avec cet ensemble de données, les Strongylida sont considérés comme un clade monophylétique emboîté au sein des Rhabditina. Les Ascaridida, Oxyurida et Spirurida sont étroitement reliés, mais jusqu’à présent sans relation étroite claire avec des taxons de nématode libre. Les Strongyloides spp. ont évolué à partir des cephalobides/tylenchides. Lorsqu’elles sont disponibles, les données issues d’autres séquences confirment le plus souvent ces relations.


Nematology ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 837-850 ◽  
Author(s):  
Kan Zhuo ◽  
Xingtong Liu ◽  
Ye Tao ◽  
Honghong Wang ◽  
Borong Lin ◽  
...  

Summary In a recent survey of plant-parasitic nematodes associated with forest in China, three species of Paratylenchus, including P. aculentus, P. leptos and P. rostrocaudatus, were found. Paratylenchus leptos and P. rostrocaudatus are new records for China and the male of P. rostrocaudatus is described for the first time. Morphological descriptions, morphometrics and light microscopic photos are provided for these three species. Molecular characterisation of these species using ribosomal RNA (rRNA) D2-D3 expansion domains of large subunit (LSU D2-D3), internal transcribed spacer (ITS) and small subunit (SSU) sequences are also given. Except for the ITS sequence of P. aculentus, other sequences were amplified for the first time. Phylogenetic relationships within the genus Paratylenchus are discussed as inferred from the analyses of LSU D2-D3, ITS and SSU.


Nematology ◽  
2016 ◽  
Vol 18 (2) ◽  
pp. 221-233 ◽  
Author(s):  
Natsumi Kanzaki ◽  
Tatsuya Ide

Diplogasteroides luxuriosae n. sp. is described from a species of longhorn beetle, Acalolepta luxuriosa (Cerambycidae), associated with a broad-leaved tree, Aralia elata (Araliaceae), from the Ibaraki and Kyoto Prefectures of Japan. Besides its generic (or intrageneric species group-specific) characteristics, the new species is characterised and distinguished from its close relatives by its apomorphic characteristics, i.e., broad spicule with a trapezoidal shape, gubernaculum with pointed anterior, and posterior ends with two gland-like cells dorsally overlapping the vas deferens of males and large and wide receptaculum seminis of females. The new species is molecularly similar to two recently described Diplogasteroides spp., D. andrassyi and D. asiaticus. However, D. luxuriosae n. sp. is molecularly distinguished from these two species by the 6-7 bp difference in near-full-length small subunit (18S) and 10-14 bp differences in D2-D3 expansion segments of large subunit (28S) ribosomal RNA genes.


Author(s):  
Johan Roenby ◽  
Hassan Aref

The model of body–vortex interactions, where the fluid flow is planar, ideal and unbounded, and the vortex is a point vortex, is studied. The body may have a constant circulation around it. The governing equations for the general case of a freely moving body of arbitrary shape and mass density and an arbitrary number of point vortices are presented. The case of a body and a single vortex is then investigated numerically in detail. In this paper, the body is a homogeneous, elliptical cylinder. For large body–vortex separations, the system behaves much like a vortex pair regardless of body shape. The case of a circle is integrable. As the body is made slightly elliptic, a chaotic region grows from an unstable relative equilibrium of the circle-vortex case. The case of a cylindrical body of any shape moving in fluid otherwise at rest is also integrable. A second transition to chaos arises from the limit between rocking and tumbling motion of the body known in this case. In both instances, the chaos may be detected both in the body motion and in the vortex motion. The effect of increasing body mass at a fixed body shape is to damp the chaos.


Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 523
Author(s):  
Marianne Lebbad ◽  
Jadwiga Winiecka-Krusnell ◽  
Christen Rune Stensvold ◽  
Jessica Beser

The intestinal protozoan parasite Cryptosporidium is an important cause of diarrheal disease worldwide. The aim of this study was to expand the knowledge on the molecular epidemiology of human cryptosporidiosis in Sweden to better understand transmission patterns and potential zoonotic sources. Cryptosporidium-positive fecal samples were collected between January 2013 and December 2014 from 12 regional clinical microbiology laboratories in Sweden. Species and subtype determination was achieved using small subunit ribosomal RNA and 60 kDa glycoprotein gene analysis. Samples were available for 398 patients, of whom 250 (63%) and 138 (35%) had acquired the infection in Sweden and abroad, respectively. Species identification was successful for 95% (379/398) of the samples, revealing 12 species/genotypes: Cryptosporidium parvum (n = 299), C. hominis (n = 49), C. meleagridis (n = 8), C. cuniculus (n = 5), Cryptosporidium chipmunk genotype I (n = 5), C. felis (n = 4), C. erinacei (n = 2), C. ubiquitum (n = 2), and one each of C. suis, C. viatorum, C. ditrichi, and Cryptosporidium horse genotype. One patient was co-infected with C. parvum and C. hominis. Subtyping was successful for all species/genotypes, except for C. ditrichi, and revealed large diversity, with 29 subtype families (including 4 novel ones: C. parvum IIr, IIs, IIt, and Cryptosporidium horse genotype VIc) and 81 different subtypes. The most common subtype families were IIa (n = 164) and IId (n = 118) for C. parvum and Ib (n = 26) and Ia (n = 12) for C. hominis. Infections caused by the zoonotic C. parvum subtype families IIa and IId dominated both in patients infected in Sweden and abroad, while most C. hominis cases were travel-related. Infections caused by non-hominis and non-parvum species were quite common (8%) and equally represented in cases infected in Sweden and abroad.


1986 ◽  
Vol 261 (11) ◽  
pp. 5187-5193
Author(s):  
M N Schnare ◽  
T Y Heinonen ◽  
P G Young ◽  
M W Gray

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  

Abstract Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.


1996 ◽  
Vol 31 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Gary W. Saunders ◽  
Isabelle M. Strachan ◽  
John A. West ◽  
Gerald T. Kraft

Author(s):  
Tulio F. Villalobos-Guerrero ◽  
Taeseo Park ◽  
Izwandy Idris

Abstract The present study reviews Perinereis Group 2 species from the Eastern and South-eastern Asian seas based on morphological analysis of the types, non-types and original descriptions, and the use of molecular evidence (COI and 16S rDNA) from newly collected material. These species are characterized by having two bar-shaped paragnaths on pharyngeal area VI, which are often deemed conical when small and pointed, triggering misidentifications as to Neanthes species. New terminology and definition for this particular type of bars are proposed, and the generic position of some resembling Neanthes species is also re-assessed. Five species are transferred to Perinereis: Perinereis babuzai comb. nov., P. belawanensis comb. nov., P. kinmenensis comb. nov., P. shigungensis comb. nov. and P. vitabunda comb. nov. ‘Perinereis aibuhitensis’ species group is newly proposed by encompassing species having proximal dorsal ligule similar throughout the body, dorsal cirri short, and blades of heterogomph falcigers straight with long terminal tooth forming a distinct tendon. Perinereis belawanensis comb. nov., P. linea and P. vitabunda comb. nov. are redescribed. Perinereis linea is regarded as a senior synonym of Nereis (Neanthes) orientalis and Perinereis vancaurica tetradentata based on type material, whereas its exotic status in the Mediterranean Sea is questioned. An identification key to all currently valid species within Perinereis Group 2 is also provided.


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