| 1. |
- Ahmed, Mohammed, et al.
(författare)
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A draft transcriptome of a parasite Neocamacolaimus parasiticus (Camacolaimidae, Plectida)
- 2021
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Ingår i: Journal of nematology. - : Walter de Gruyter GmbH. - 0022-300X .- 2640-396X. ; 53
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Tidskriftsartikel (refereegranskat)abstract
- Camacolaimidae is a clade of nematodes that include both freeliving epistrate feeding forms and parasites of marine protozoans and invertebrates. Neocamacolaimus parasiticus is a parasite of marine polychaete worms. Given its phylogenetic affinities to free-living species, Neocamacolaimus can be a reference for research of the origin of parasitism in an aquatic environment. Here, we present a draft transcriptome obtained from a single post-parasitic juvenile individual of this species. The final assembly consists of 19,180 protein coding sequences (including isoforms) with the following BUSCO scores for Nematoda: 65.38% complete, 9.06% partial, and 25.56% missing, and for Metazoa: 79.45% complete, 3.17% partial, and 17.38% missing.
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| 2. |
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| 3. |
- Ahmed, Mohammed, et al.
(författare)
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Description of a new marine predatory nematode Latronema dyngi sp. nov. (Nematoda, Chromadorida, Selachinematidae) from the west coast of Sweden and an updated phylogeny of Chromadoria
- 2020
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Ingår i: Marine Biodiversity. - : Springer Science and Business Media LLC. - 1867-1616 .- 1867-1624. ; 50:113, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- A new nematode species, Latronema dyngi sp. nov., is described from Skagerrak off the west coast of Sweden with the type locality near Dyngö island. Latronema dyngi sp. nov. is characterized by multispiral amphideal fovea with circular outline, 0.2– 0.3 corresponding body diameters wide in males and 0.1–0.2 corresponding body diameters wide in females, 12 cuticular longitudinal ridges and 18–27 precloacal supplements in males. Latronema dyngi sp. nov. most closely resembles L. orcinum in terms of body length; demanian ratios a, b, c and c′; number of amphid turns in males; and the ratio of spicule length to cloacal body diameter. The two species can be differentiated by the number longitudinal ridges on the cuticle (12 for Latronema dyngi sp. nov. vs 20–22 for L. orcinum) and spicule length (65–78 μm for L. dyngi vs 60 for L. orcinum) and shape (weakly arcuate for L. dyngi sp. nov. vs strongly arcuate for L. orcinum). We also performed a maximum likelihood phylogenetic analysis on over 250 nematodes of the subclass Chromadoria based on their nearly full-length 18S rDNA sequences. In agreement with previous studies, our analysis supported Selachinematidae as a monophyletic group and placed Richtersia Steiner, 1916 within Desmodoridae Filipjev, 1922 or just outside of the main Desmodorida clade with the latter placement not well supported.
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| 4. |
- Ahmed, Mohammed, et al.
(författare)
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Phylogenomic Analysis of the Phylum Nematoda: Conflicts and Congruences With Morphology, 18S rRNA, and Mitogenomes
- 2022
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Ingår i: Frontiers in Ecology and Evolution. - : Frontiers Media SA. - 2296-701X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic relationships within many lineages of the phylum Nematoda remainunresolved, despite numerous morphology-based and molecular analyses. Weperformed several phylogenomic analyses using 286 published genomes andtranscriptomes and 19 new transcriptomes by focusing on Trichinellida, Spirurina,Rhabditina, and Tylenchina separately, and by analyzing a selection of species fromthe whole phylum Nematoda. The phylogeny of Trichinellida supported the divisionof Trichinella into encapsulated and non-encapsulated species and placed them assister to Trichuris. The Spirurina subtree supported the clades formed by species fromAscaridomorpha and Spiruromorpha respectively, but did not support Dracunculoidea.The analysis of Tylenchina supported a clade that included all sampled species fromTylenchomorpha and placed it as sister to clades that included sampled speciesfrom Cephalobomorpha and Panagrolaimomorpha, supporting the hypothesis thatpostulates the single origin of the stomatostylet. The Rhabditina subtree placed a cladecomposed of all sampled species from Diplogastridae as sister to a lineage consistingof paraphyletic Rhabditidae, a single representative of Heterorhabditidae and a cladecomposed of sampled species belonging to Strongylida. It also strongly supportedall suborders within Strongylida. In the phylum-wide analysis, a clade composedof all sampled species belonging to Enoplia were consistently placed as sister toDorylaimia + Chromadoria. The topology of the Nematoda backbone was consistentwith previous studies, including polyphyletic placement of sampled representatives ofMonhysterida and Araeolaimida.
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| 5. |
- Ahmed, Mohammed, et al.
(författare)
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Revision of the genus Cobbionema Filipjev, 1922 (Nematoda, Chromadorida, Selachinematidae)
- 2020
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Ingår i: European journal of taxonomy. - : Museum National D'Histoire Naturelle. - 2118-9773. ; 702, s. 1-34
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the genus Cobbionema Filipjev, 1922 in Sweden with the description of four species and a revision of the genus. Cobbionema acrocerca Filipjev, 1922 is relatively small in size, with a tail that has a conical proximal and a digitate distal section. Cobbionema cylindrolaimoides Schuurmans Stekhoven, 1950 is similar to C. acrocerca in most characters except having a larger body size and heavily cuticularized mandibles. Cobbionema brevispicula sp. nov. is characterised by short spicules and a conoid tail. Cobbionema acuminata sp. nov. is characterised by a long two-part spicule, a conical tail and three (one mid dorsal and two ventrosublateral) sharply pointed tines in the anterior chamber of the stoma that are located more anterior than in all the other species. We also present a molecular phylogeny of the family based on the nearly full-length 18S and the D2-D3 expansion segment of the 28S rRNA genes. Maximum Likelihood and Bayesian trees inferred from both genes strongly support a clade that included Cobbionema, Demonema Cobb, 1894 and Halichoanolaimus de Man, 1888 and another clade with Gammanema Cobb, 1920 and Latronema Wieser, 1954 nested together. None of the trees supported the monophyly of the subfamilies Choniolaiminae and Selachinematinae.
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| 6. |
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| 7. |
- Ahmed, Mohammed, et al.
(författare)
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Twenty Years after De Ley and Blaxter—How Far Did We Progress in Understanding the Phylogeny of the Phylum Nematoda?
- 2021
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Ingår i: Animals. - : MDPI AG. - 2076-2615. ; 11:12, s. 3479-3479
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Tidskriftsartikel (refereegranskat)abstract
- Molecular phylogenetics brought radical changes to our understanding of nematode evolution, resulting in substantial modifications to nematode classification implemented by De Ley and Blaxter and widely accepted now. Numerous phylogenetic studies were subsequently published that both improved and challenged this classification. Here we present a summary of these changes. We created cladograms that summarise phylogenetic relationships within Nematoda using phylum-wide to superfamily-wide molecular phylogenies published in since 2005, and supplemented with the phylogenetic analyses for Enoplia and Chromadoria with the aim of clarifying the position of several taxa. The results show which parts of the Nematode tree are well resolved and understood, and which parts require more research, either by adding taxa that have not been included yet (increasing taxon coverage), or by changing the phylogenetic approach (improving data quality, using different types of data or different methods of analysis). The currently used classification of the phylum Nematoda in many cases does not reflect the phylogeny and in itself requires numerous improvements and rearrangements.
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| 8. |
- Balog, Luca Eszter, et al.
(författare)
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PREVALENCE AND DISTRIBUTION OF DIFFERENT NATURAL ENEMIES IN THE HARLEQUIN LADYBIRD HARMONIA AXYRIDIS (COLEOPTERA COCCINELLIDAE)
- 2021
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Ingår i: Redia. - : CREA - DC. - 0370-4327.
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Tidskriftsartikel (refereegranskat)abstract
- The harlequin ladybird Harmonia axyridis (Coleoptera: Coccinellidae) is one of the most common invasive alien species in the world, which has a global impact on biodiversity and agriculture, and causes economic loss and harm to humans. This insect can be infected by different natural enemies, but their interactions remain understudied. In the present study, 581 adult Ha. axyridis specimens were collected from 21 localities in Hungary with the help of citizen scientists and examined for natural enemies. The parasitic nematode Parasitylenchus bifurcatus (Nematoda: Allantonematidae) is reported in Hungary on the harlequin ladybird for the first time. The ladybirds were also infected by the ectoparasitic fungus Hesperomyces virescens (Ascomycota: Laboulbeniales) and parasitoid Dinocampus coccinellae (Hymenoptera: Braconidae). The nematode parasite was present in all localities where Hesperomyces-infected ladybirds appeared. The prevalence of recorded natural enemies varied by locality: for P. bifurcatus it ranged from 1% to 8%; for He. virescens from 2% to 36%; and for the parasitoid it was 4%. Besides, a statistically significant positive correlation was shown between the nematode and the fungus co-infection using Spearman’s correlation. A study on the multiparasitism of harlequin ladybirds was not yet performed in Hungary. The study area is located between two distant areas in Europe where co-infections had already been observed, indicating that this is probably not a sporadic phenomenon, but that parasitism of the harlequin ladybird by multiple natural enemies might be prevalent throughout the area.
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| 9. |
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| 10. |
- Boscaro, Vittorio, et al.
(författare)
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Microbiomes of microscopic marine invertebrates do not reveal signatures of phylosymbiosis
- 2022
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Ingår i: Nature Microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 7:6, s. 810-819
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Tidskriftsartikel (refereegranskat)abstract
- Animals and microorganisms often establish close ecological relationships. However, much of our knowledge about animal microbiomes comes from two deeply studied groups: vertebrates and arthropods. To understand interactions on a broader scale of diversity, we characterized the bacterial microbiomes of close to 1,000 microscopic marine invertebrates from 21 phyla, spanning most of the remaining tree of metazoans. Samples were collected from five temperate and tropical locations covering three marine habitats (sediment, water column and intertidal macroalgae) and bacterial microbiomes were characterized using 16S ribosomal RNA gene sequencing. Our data show that, despite their size, these animals harbour bacterial communities that differ from those in the surrounding environment. Distantly related but coexisting invertebrates tend to share many of the same bacteria, suggesting that guilds of microorganisms preferentially associated with animals, but not tied to any specific host lineage, are the main drivers of the ecological relationship. Host identity is a minor factor shaping these microbiomes, which do not show the same correlation with host phylogeny, or ‘phylosymbiosis’, observed in many large animals. Hence, the current debate on the varying strength of phylosymbiosis within selected lineages should be reframed to account for the possibility that such a pattern might be the exception rather than the rule.
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