| 1. |
- Abalde, Samuel, et al.
(författare)
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A Combined Transcriptomics and Proteomics Approach Reveals the Differences in the Predatory and Defensive Venoms of the Molluscivorous Cone Snail Cylinder ammiralis (Caenogastropoda: Conidae)
- 2021
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Ingår i: Toxins. - : MDPI AG. - 2072-6651. ; 13:9, s. 642-642
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Tidskriftsartikel (refereegranskat)abstract
- Venoms are complex mixtures of proteins that have evolved repeatedly in the animal kingdom. Cone snail venoms represent one of the best studied venom systems. In nature, this venom can be dynamically adjusted depending on its final purpose, whether to deter predators or hunt prey. Here, the transcriptome of the venom gland and the proteomes of the predation-evoked and defensive venoms of the molluscivorous cone snail Cylinder ammiralis were catalogued. A total of 242 venom-related transcripts were annotated. The conotoxin superfamilies presenting more different peptides were O1, O2, T, and M, which also showed high expression levels (except T). The three precursors of the J superfamily were also highly expressed. The predation-evoked and defensive venoms showed a markedly distinct profile. A total of 217 different peptides were identified, with half of them being unique to one venom. A total of 59 peptides ascribed to 23 different protein families were found to be exclusive to the predatory venom, including the cono-insulin, which was, for the first time, identified in an injected venom. A total of 43 peptides from 20 protein families were exclusive to the defensive venom. Finally, comparisons of the relative abundance (in terms of number of peptides) of the different conotoxin precursor superfamilies showed that most of them present similar abundance regardless of the diet.
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| 2. |
- Abalde, Samuel, et al.
(författare)
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Hidden species diversity and mito-nuclear discordance within the Mediterranean cone snail, Lautoconus ventricosus
- 2023
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Ingår i: Molecular Phylogenetics and Evolution. - 1055-7903 .- 1095-9513. ; 186, s. 107838-107838
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Tidskriftsartikel (refereegranskat)abstract
- The Mediterranean cone snail, Lautoconus ventricosus, is currently considered a single species inhabiting the whole Mediterranean basin and the adjacent Atlantic coasts. Yet, no population genetic study has assessed its taxonomic status. Here, we collected 245 individuals from 75 localities throughout the Mediterranean Sea and used cox1 barcodes, complete mitochondrial genomes, and genome skims to test whether L. ventricosus represents a complex of cryptic species. The maximum likelihood phylogeny based on complete mitochondrial genomes recovered six main clades (hereby named blue, brown, green, orange, red, and violet) with sufficient sequence divergence to be considered putative species. On the other hand, phylogenomic analyses based on 437 nuclear genes only recovered four out of the six clades: blue and orange clades were thoroughly mixed and the brown one was not recovered. This mito-nuclear discordance revealed instances of incomplete lineage sorting and introgression, and may have caused important differences in the dating of main cladogenetic events. Species delimitation tests proposed the existence of at least three species: green, violet, and red + blue + orange (i.e., cyan). Green plus cyan (with sympatric distributions) and violet, had West and East Mediterranean distributions, respectively, mostly separated by the Siculo-Tunisian biogeographical barrier. Morphometric analyses of the shell using species hypotheses as factor and shell length as covariate showed that the discrimination power of the studied parameters was only 70.2%, reinforcing the cryptic nature of the uncovered species, and the importance of integrative taxonomic approaches considering morphology, ecology, biogeography, and mitochondrial and nuclear population genetic variation.
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| 3. |
- Irisarri, Iker, 1984-, et al.
(författare)
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A mitogenomic phylogeny of chitons (Mollusca: Polyplacophora)
- 2020
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPolyplacophora, or chitons, have long fascinated malacologists for their distinct and rather conserved morphology and lifestyle compared to other mollusk classes. However, key aspects of their phylogeny and evolution remain unclear due to the few morphological, molecular, or combined phylogenetic analyses, particularly those addressing the relationships among the major chiton lineages.ResultsHere, we present a mitogenomic phylogeny of chitons based on 13 newly sequenced mitochondrial genomes along with eight available ones and RNAseq-derived mitochondrial sequences from four additional species. Reconstructed phylogenies largely agreed with the latest advances in chiton systematics and integrative taxonomy but we identified some conflicts that call for taxonomic revisions. Despite an overall conserved gene order in chiton mitogenomes, we described three new rearrangements that might have taxonomic utility and reconstructed the most likely scenario of gene order change in this group. Our phylogeny was time-calibrated using various fossils and relaxed molecular clocks, and the robustness of these analyses was assessed with several sensitivity analyses. The inferred ages largely agreed with previous molecular clock estimates and the fossil record, but we also noted that the ambiguities inherent to the chiton fossil record might confound molecular clock analyses.ConclusionsIn light of the reconstructed time-calibrated framework, we discuss the evolution of key morphological features and call for a continued effort towards clarifying the phylogeny and evolution of chitons.
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| 4. |
- Pardos-Blas, José Ramón, et al.
(författare)
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The genome of the venomous snail Lautoconus ventricosus sheds light on the origin of conotoxin diversity
- 2021
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Ingår i: GigaScience. - : Oxford University Press (OUP). - 2047-217X. ; 10:5, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Venoms are deadly weapons to subdue prey or deter predators that have evolved independently in many animal lineages. The genomes of venomous animals are essential to understand the evolutionary mechanisms involved inthe origin and diversification of venoms. Results: Here, we report the chromosome-level genome of the venomous Mediterranean cone snail, Lautoconus ventricosus (Caenogastropoda: Conidae). The total size of the assembly is 3.59 Gb; ithas high contiguity (N50 = 93.53 Mb) and 86.6 Mb of the genome assembled into the 35 largest scaffolds or pseudochromosomes. On the basis of venom gland transcriptomes, we annotated 262 complete genes encoding conotoxin precursors, hormones, and other venom-related proteins. These genes were scattered in the different pseudochromosomesand located within repetitive regions. The genes encoding conotoxin precursors were normally structured into 3 exons,which did not necessarily coincide with the 3 structural domains of the corresponding proteins. Additionally, we found evidence in the L. ventricosus genome for a past whole-genome duplication event by means of conserved gene synteny withthe Pomacea canaliculata genome, the only one available at the chromosome level within Caenogastropoda. The whole-genome duplication event was further confirmed by the presence of a duplicated hox gene cluster. Key genes for gastropod biology including those encoding proteins related to development, shell formation, and sex were located inthe genome. Conclusions: The new high-quality L. ventricosus genome should become a reference for assembling andanalyzing new gastropod genomes and will contribute to future evolutionary genomic studies among venomous animals.
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| 5. |
- Uribe, Juan E., et al.
(författare)
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New patellogastropod mitogenomes help counteracting long-branch attraction in the deep phylogeny of gastropod mollusks
- 2019
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Ingår i: Molecular Phylogenetics and Evolution. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 1055-7903 .- 1095-9513. ; 133, s. 12-23
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Tidskriftsartikel (refereegranskat)abstract
- Long-branch attraction (LBA) is a well-known artifact in phylogenetic reconstruction. Sparse taxon sampling and extreme heterogeneity of evolutionary rates among lineages generate propitious situations for LBA, even defying probabilistic methods of phylogenetic inference. A clear example illustrating LBA challenges is the difficulty of reconstructing the deep gastropod phylogeny, particularly using mitochondrial (mt) genomes. Previous studies consistently obtained unorthodox phylogenetic relationships due to the LBA between the mitogenomes of patellogastropods (true limpets, represented only by Lottia digitalis), heterobranchs, and outgroup taxa. Here, we use the reconstruction of the gastropod mitogenomic phylogeny as a case exercise to test the effect of key methodological approaches proposed to counteract LBA, including the selection of slow-evolving representatives, the use of different outgroups, the application of site-heterogeneous evolutionary models, and the removal of fast-evolving sites. In this regard, we sequenced three new patellogastropod mt genomes, which displayed shorter branches than the one of Lottia as well as gene organizations more similar to that of the hypothetical gastropod ancestor. Phylogenetic analyses incorporating the mt genomes of Patella ferruginea, Patella vulgata, and Cellana radiata allowed eliminating the artificial clustering of Patellogastropoda and Heterobranchia that had prevailed in previous studies. Furthermore, the use of site-heterogeneous models with certain combinations of lineages within the outgroup allowed eliminating also the LBA between Heterobranchia and the outgroup, and recovering Apogastropoda (i.e., Caenogastropoda + Heterobranchia). Hence, for the first time, we were able to obtain a mitogenomic phylogeny of gastropods that is congruent with both morphological and nuclear datasets.
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