scholarly journals Diversity and Eco-Evolutionary Associations of Endosymbiotic Astome Ciliates With Their Lumbricid Earthworm Hosts

2021 ◽  
Vol 12 ◽  
Author(s):  
Tomáš Obert ◽  
Ivan Rurik ◽  
Peter Vd’ačný
Keyword(s):  
Host Specificity ◽  
Evolutionary Biology ◽  
18S Rrna Gene ◽  
Its2 Region ◽  
Rrna Gene ◽  
28S Rrna ◽  
Nuclear Markers ◽  
New Host ◽  
Host Switch ◽  
Duplication Events

Coevolution of endosymbionts with their hosts plays an important role in the processes of speciation and is among the most fascinating topics in evolutionary biology. Astome ciliates represent an interesting model for coevolutionary studies because they are so tightly associated with their host organisms that they completely lost the cell oral apparatus. In the present study, we used five nuclear markers (18S rRNA gene, ITS1–5.8S–ITS2 region, and 28S rRNA gene) and two mitochondrial genes (16S rRNA gene and cytochrome c oxidase subunit I) to explore the diversity of astomes inhabiting the digestive tract of lumbricid earthworms at temperate latitudes in Central Europe and to cast more light on their host specificity and coevolution events that shaped their diversification. The present coevolutionary and phylogenetic interaction-adjusted similarity analyses suggested that almost every host switch leads to speciation and firm association with the new host. Nevertheless, the suggested high structural host specificity of astomes needs to be tested with increased earthworm sampling, as only 52 out of 735 lumbricid earthworms (7.07%) were inhabited by ciliates. On the other hand, the diversification of astomes associated with megascolecid and glossoscolecid earthworms might have been driven by duplication events without host switching.

Stephanoprora amurensis sp. nov., Echinochasmus milvi Yamaguti, 1939 and E. suifunensis Besprozvannykh, 1991 from the Russian southern Far East and their phylogenetic relationships within the Echinochasmidae Odhner 1910

Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1469-1479
Author(s):  
Y. V. Tatonova ◽  
A. V. Izrailskaia ◽  
V. V. Besprozvannykh
Keyword(s):  
Dna Markers ◽  
Phylogenetic Relationships ◽  
Developmental Stages ◽  
Far East ◽  
Genetic Data ◽  
Freshwater Snails ◽  
Its2 Region ◽  
Rrna Gene ◽  
28S Rrna ◽  
Southern Far East

AbstractMature worms of Stephanoprora amurensis sp. nov. were obtained in an experimental study of its life cycle. In the Russian southern Far East, this trematode circulates using freshwater snails Parajuga subtegulata, freshwater fish and birds as the first, second intermediate and final hosts, respectively. Stephanoprora amurensis sp. nov. differs from the well-known representatives of Stephanoprora in a number of morphometric indicators of the developmental stages. The validity of the species was also confirmed by nuclear and mitochondrial DNA markers. In addition, new genetic data were obtained for Echinochasmus suifunensis and Echinochasmus milvi. An analysis of phylogenetic relationships within Echinochasmidae based on the 28S rRNA gene and ITS2 region identified two clusters, one of which combines species of Echinochasmus with 20–22 collar spines and short-tailed cercariae, and the other which includes Stephanoprora spp. and a number of representatives of Echinochasmus with 24 collar spines and long-tailed cercariae. The results of phylogenetic analysis based on ITS2 data show interfamily level of differences between the two clusters and intergeneric differentiation between the three subclusters uniting the species of Stephanoprora and Echinochasmus.

scholarly journals Genotypic Characterization of Torymus sinensis (Hymenoptera: Torymidae) After Its Introduction in Tuscany (Italy) for the Biological Control of Dryocosmus kuriphilus (Hymenoptera: Cynipidae)

2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Ambra Viviani ◽  
Rodolfo Bernardi ◽  
Andrea Cavallini ◽  
Elisabetta Rossi
Keyword(s):  
Biological Control ◽  
18S Rrna ◽  
18S Rrna Gene ◽  
Its2 Region ◽  
Rrna Gene ◽  
Gall Wasp ◽  
Dryocosmus Kuriphilus ◽  
Torymus Sinensis ◽  
The World

Abstract Torymus sinensis Kamijo (Hymenoptera: Torymidae) is an alien parasitoid that is used in many areas of the world for biological control the Asian chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae). In Italy, this parasitoid was imported from Japan in 2003 and subsequently multiplied and released throughout the country. In this study, a phylogenetic investigation was carried out on insects from three different sites in northern Tuscany (Italy). Moreover, the possible hybridization between T. sinensis and some native Torymus species was evaluated. The conserved region 18S rRNA gene and the hypervariable ITS2 (Internal Transcribed Spacer 2) region of the ribosomal cistrone were selected as molecular markers. Sequencing the amplified products, after cloning, ruled out any hybridization between T. sinensis and the native Torymus species, and also confirmed the presence of two haplotypes for the Tuscan population of T. sinensis both for the region of the 18S rRNA gene as well as for the ITS2 region. These results confirm that the environmental impact of the alien parasitoid T. sinensis in the study site is acceptable, although an extensive and repeated monitoring would be desirable.

Morphological and molecular characterization of Mermisnigrescens Dujardin, (Nematoda: Mermithidae) parasitizing the introduced European earwig (Dermaptera: Forficulidae) in New Zealand

2014 ◽  
Vol 89 (3) ◽  
pp. 267-276 ◽  
Author(s):  
B. Presswell ◽  
S. Evans ◽  
R. Poulin ◽  
F. Jorge
Keyword(s):  
New Zealand ◽  
18S Rrna ◽  
Sequence Data ◽  
18S Rrna Gene ◽  
Parasitic Nematodes ◽  
Rrna Gene ◽  
28S Rrna ◽  
Forficula Auricularia ◽  
Adult Females ◽  
European Earwig

AbstractParasitic nematodes of the family Mermithidae were found to be infecting the introduced European earwig Forficula auricularia (Dermaptera: Forficulidae) in Dunedin, South Island, New Zealand. Adult females were later collected from various garden plants while depositing eggs. These mermithid specimens were identified morphologically as Mermis nigrescens Dujardin, 1842. A genetic distance of 0.7% between these specimens and a M. nigrescens isolate from Canada (18S rRNA gene), suggests that they have diverged genetically, but there are currently no available comparable sequences for the European M. nigrescens. Two additional nuclear fragments were also amplified, the 28S rRNA and the ribosomal DNA first internal transcribed spacer (ITS1), providing a basis for future studies. Bearing in mind the morphological similarity with other reported M. nigrescens and the lack of sequence data from other parts of the world, we retain the name M.nigrescens, and suggest that the species may be found to represent a complex of cryptic species when more worldwide data are available. Herein, we present a brief description of the post-parasitic worms and adult females, along with an inferred phylogeny using 18S rRNA gene sequences.

Mononchoides macrospiculum n. sp. (Nematoda: Neodiplogastridae) and Teratorhabditis synpapillata Sudhaus, 1985 (Nematoda: Rhabditidae): nematode associates of Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae) in Italy

Nematology ◽  
2015 ◽  
Vol 17 (8) ◽  
pp. 953-966 ◽  
Author(s):  
Alberto Troccoli ◽  
Monica Oreste ◽  
Eustachio Tarasco ◽  
Elena Fanelli ◽  
Francesca De Luca
Keyword(s):  
Molecular Level ◽  
Phylogenetic Analyses ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
28S Rrna ◽  
Italian Population ◽  
Rhynchophorus Ferrugineus ◽  
Red Palm Weevil ◽  
Palm Weevil ◽  
Mitochondrial Cytochrome Oxidase

Several juvenile and adult nematodes were isolated after dissection of pupae and adults of the red palm weevil,Rhynchophorus ferrugineus, recovered from an infestedPhoenix canariensisChabaud exemplar in Bari, Italy. Two species of nematodes were recovered,Teratorhabditis synpapillataandMononchoides macrospiculumn. sp. which is described herein. The mitochondrial cytochrome oxidase I (COI), the ITS-containing region, the 18S rRNA gene (SSU) and the D2-D3 expansion domains of the 28S rRNA gene (LSU) were amplified and sequenced. The new species,M. macrospiculumn. sp., is described at morphological and molecular level. Phylogenetic analyses using SSU and LSU sequences placedM. macrospiculumn. sp. together withM. composticolaandM. striatus. The sequences of the Italian population ofT. synpapillataare identical to those ofT. synpapillatafrom Japan. This is the first report on the association ofM. macrospiculumn. sp. andT. synpapillatawith the red palm weevil in Europe.

Multilocus phylogeny, species delimitation and biogeography of Iberian valvatiform springsnails (Caenogastropoda: Hydrobiidae), with the description of a new genus

2019 ◽  
Vol 186 (4) ◽  
pp. 892-914 ◽  
Author(s):  
Diana Delicado ◽  
Beatriz Arconada ◽  
Amanda Aguado ◽  
Marian A Ramos
Keyword(s):  
Iberian Peninsula ◽  
Species Delimitation ◽  
New Genus ◽  
Phylogenetic Analyses ◽  
18S Rrna Gene ◽  
Physical Geography ◽  
Rrna Gene ◽  
Nominal Species ◽  
28S Rrna

Abstract Valvatiform gastropods of the family Hydrobiidae are frequently found in European spring-fed systems. Their simplified and sometimes convergent morphological structures and restricted geographical ranges make the description and identification of valvatiform species challenging. In the Iberian Peninsula, to date, 20 valvatiform species have been described morphologically. To test morphological species delimitations and to evaluate the role of physical geography on their evolutionary history, we analysed two mitochondrial (COI and 16S rRNA) and two nuclear (28S rRNA and 18S rRNA) gene fragments of 16 valvatiform species from the Iberian Peninsula. Molecular species delimitation methods consistently inferred 11 of the nominal species. Our phylogenetic analyses recovered the species Islamia azarum as an independent lineage, distantly related to other genera, which we place in the new genus Deganta. Furthermore, Iberian valvatiform hydrobiids do not form a monophyletic subunit, but they are included in two distinct clades of Hydrobiidae. Divergence times indicate that speciation in these clades is likely to have coincided with the formation of major Iberian mountain ranges and river basins. Similarities of geographical subdivision and divergent times between this assemblage and the non-valvatiform genus Corrosella provide strong evidence for the role of the Iberian geographical barriers in shaping the biogeography of these springsnails.

Molecular characterisation of two known species of Paratylenchus Micoletzky, 1922 from Iran with notes on the validity of Paratylenchus audriellus Brown, 1959

Nematology ◽  
2016 ◽  
Vol 18 (5) ◽  
pp. 591-604 ◽  
Author(s):  
Mehrab Esmaeili ◽  
Ramin Heydari ◽  
Pablo Castillo ◽  
Mozhgan Ziaie Bidhendi ◽  
Juan E. Palomares-Rius
Keyword(s):  
18S Rrna ◽  
First Record ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
28S Rrna ◽  
Molecular Characterisation ◽  
Female Tail ◽  
Valid Taxon ◽  
Two Populations ◽  
Partial 18S

During a survey on pin nematodes in western Iran, two populations of Paratylenchus audriellus and Paratylenchus tenuicaudatus were collected and subsequently analysed morphologically and molecularly. Paratylenchus audriellus is characterised by the long stylet (48-61 μm) and the typical female tail with a characteristic claw-like process with sharply pointed terminus. To our knowledge, the Iranian population of P. tenuicaudatus is the first record from Iran. The molecular characterisation of P. audriellus nematodes using the D2-D3 of 28S rRNA and the partial 18S rRNA gene sequences revealed that this species is clearly separated from P. straeleni and should be considered as a valid taxon.

scholarly journals Assessing the Pathogenicity of Two Bacteria Isolated from the Entomopathogenic Nematode Heterorhabditis indica against Galleria mellonella and Some Pest Insects

Insects ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 83
Author(s):  
Rosalba Salgado-Morales ◽  
Fernando Martínez-Ocampo ◽  
Verónica Obregón-Barboza ◽  
Kathia Vilchis-Martínez ◽  
Alfredo Jiménez-Pérez ◽  
...  
Keyword(s):  
16S Rrna ◽  
Galleria Mellonella ◽  
De Novo ◽  
Entomopathogenic Nematode ◽  
23S Rrna ◽  
Its2 Region ◽  
Rrna Gene ◽  
28S Rrna ◽  
Heterorhabditis Indica ◽  
Insecticide Activity

The entomopathogenic nematodes Heterorhabditis are parasites of insects and are associated with mutualist symbiosis enterobacteria of the genus Photorhabdus; these bacteria are lethal to their host insects. Heterorhabditis indica MOR03 was isolated from sugarcane soil in Morelos state, Mexico. The molecular identification of the nematode was confirmed using sequences of the ITS1-5.8S-ITS2 region and the D2/D3 expansion segment of the 28S rRNA gene. In addition, two bacteria HIM3 and NA04 strains were isolated from the entomopathogenic nematode. The genomes of both bacteria were sequenced and assembled de novo. Phylogenetic analysis was confirmed by concatenated gene sequence datasets as Photorhabdus luminescens HIM3 (16S rRNA, 23S rRNA, dnaN, gyrA, and gyrB genes) and Pseudomonas aeruginosa NA04 (16S rRNA, 23S rRNA and gyrB genes). H. indica MOR03 infects Galleria mellonella, Tenebrio molitor, Heliothis subflexa, and Diatraea magnifactella larvae with LC50 values of 1.4, 23.5, 13.7, and 21.7 IJs/cm2, respectively, at 48 h. These bacteria are pathogenic to various insects and have high injectable insecticide activity at 24 h.

scholarly journals Sequencing and Analysis of Fungal rRNA Operons for Development of Broad-Range Fungal PCR Assays

2009 ◽  
Vol 75 (6) ◽  
pp. 1559-1565 ◽  
Author(s):  
Prasanna D. Khot ◽  
Daisy L. Ko ◽  
David N. Fredricks
Keyword(s):  
Fungal Pathogens ◽  
18S Rrna ◽  
18S Rrna Gene ◽  
Internal Transcribed Spacers ◽  
Rrna Gene ◽  
28S Rrna ◽  
28S Rrna Gene ◽  
Fungal Dna ◽  
Pcr Assays ◽  
Distance Matrices

ABSTRACT rRNA genes are attractive targets for developing PCR assays targeting human fungal pathogens. Most studies have focused on the 18S rRNA gene, internal transcribed spacers, and the 5′ end of the 28S rRNA gene. An approximately 2,900-bp region of the 28S rRNA gene remains largely unexplored because sequences of many medically relevant fungi are either unavailable or undefined in genomic databases. The internal transcribed spacers and 28S rRNA gene of nine medically and phylogenetically important fungi were sequenced. In addition, 42 sequences from this region were acquired from public databases, resulting in an alignment of 51 fungal sequences spanning 30 fungal genera. For the nearly 3,950-bp region from the 3′ end of 18S rRNA gene to the 3′ end of the 28S rRNA gene, 27 broad-range PCR primers were designed such that their sequence homology with the human rRNA gene was minimal. All 62 possible amplicons in the size range from 75 to 400 bp from 27 primers were screened using fungal genomic DNA from 26 species spanning 14 genera. Eleven of the 62 amplicons did not cross-react with 1 μg/PCR human DNA but simultaneously amplified 10 fg of fungal DNA. Phylogenetic distance matrices were calculated for regions covered by these 11 amplicons based on 51 fungi. Two of these 11 amplicons successfully amplified 30 fg of fungal DNA from 25 of 26 fungi and provided the most phylogenetic information for species identification based on the distance matrices. These PCR assays hold promise for detection and identification of fungal pathogens in human tissues.

scholarly journals Eutylenchus excretorius Ebsary & Eveleigh, 1981 (Nematoda: Tylodorinae) from Spain with approaches to molecular phylogeny of related genera

Nematology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 343-354 ◽  
Author(s):  
Gracia Liébanas ◽  
Juan Palomares-Rius ◽  
Pablo Castillo ◽  
Sergei Subbotin ◽  
Blanca Landa
Keyword(s):  
Gene Sequence ◽  
Heat Shock Protein 90 ◽  
Common Reed ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
28S Rrna ◽  
Northern Spain ◽  
Majority Consensus ◽  
First Time ◽  
Phragmites Sp

AbstractNematode surveys in indigenous vegetation in northern Spain revealed the presence of a nematode population of the genus Eutylenchus associated with moist sandy soils in the rhizosphere of common reed (Phragmites sp.) on the banks of the Tera river in Garray (Soria province). Morphological and morphometrical studies on this population fits with Eutylenchus excretorius, representing the first report for Spain and southern Europe and the fifth report in Europe after Germany, Poland, Czech Republic and Russia. SEM studies were carried out for the first time on this species and showed four lips separated by deep grooves. Each lip bears an elongated, flexible, recurved projection (seta) 12 (11-13) μm long, proximal third wide, gradually attenuating, distal end rounded. Molecular characterisation of E. excretorius using several genes is provided. The sequence of D2-D3 expansion segments of 28S rRNA gene of this population was identical to a previously studied sample from Germany. Phylogenetic analysis using D2-D3 of 28S rRNA and partial 18S rRNA gene sequences of tylenchid nematodes revealed that E. excretorius clustered with moderate support with Cephalenchus hexalineatus. The position of E. excretorius on majority consensus Bayesian phylogenetic tree reconstructed using heat shock protein 90 gene sequence was not well resolved.

scholarly journals Molecular and morphological characterisation of Longidorus polyae sp. n. and L. pisi Edward, Misra & Singh, 1964 (Dorylaimida, Longidoridae) from Bulgaria

ZooKeys ◽  
2019 ◽  
Vol 830 ◽  
pp. 75-98 ◽  
Author(s):  
Stela S. Lazarova ◽  
Milka Elshishka ◽  
Georgi Radoslavov ◽  
Lydmila Lozanova ◽  
Peter Hristov ◽  
...  
Keyword(s):  
New Species ◽  
Body Length ◽  
Nematode Species ◽  
Molecular Data ◽  
18S Rrna Gene ◽  
The Body ◽  
Integrative Approach ◽  
Rrna Gene ◽  
28S Rrna ◽  
Stage Juvenile

Longidoruspolyaesp. n., a bisexual nematode species found in the rhizosphere of pear tree (Pyruscommunis L.), is described and characterised using an integrative approach. The new species has a female body length of 6.8–9.1 mm; a comparatively long odontostyle (114.0–127.5 μm); a narrow lip region (14.0–15.5 μm), anteriorly flattened and almost continuous with the body profile; pocket-like amphidial pouches long, deeply bilobed, and slightly asymmetrical, a guide ring at 37–42 μm from the anterior end; normal arrangement of pharyngeal glands; and a short bluntly rounded to hemispherical tail. Four juvenile stages identified: the first stage with a digitate tail, and the second and subsequent stages with a bluntly rounded tail. Males have one adcloacal pair and a row of 10 or 11 single ventromedian supplements; spicules 71.0–74.5 μm long. Based on morphometric data, the new species belongs to a group of species spread over Europe (L.arthensis, L.silvae, L.uroshis,), Iran (L.kheirii), and Syria (L.pauli), which share common characters such as amphidial fovea, lip region and tail shapes, similar odontostyle and body length, and similar first-stage juvenile tail shape. Codes for identifying the new species are A5, B2, C34, D3, E3, F45, G12, H1, I2, J1, K7. The phylogenetic analysis based on D2-D3 expansion domains of the rRNA gene revealed that the new species has the closest relationships with L.athesinus from Italy and three unidentified Longidorus spp. from USA (Longidorus sp. 1, Longidorus sp. 2, and Longidorus sp. 6). New morphometric and molecular data (18S rRNA gene, ITS1-5.8S-ITS2 regions and D2-D3 28S rRNA gene sequences) for three populations of L.pisi from Bulgaria were obtained and variations between populations are discussed.

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