Molecular detection of parasites (Trematoda, Digenea: Bucephalidae and Monorchiidae) in the European flat oyster Ostrea edulis (Mollusca: Bivalvia)

Members of the globally distributed bivalve family Ostreidae (oysters) have a significant role in marine ecosystems and include species of high economic importance. In this work, we report the occurrence of digenean parasites of the families Bucephalidae (Prosorhynchoides sp.) and Monorchiidae (Postmonorchis sp.) in Mediterranean native populations of Ostrea edulis (but not in the introduced Magallana gigas). Molecular detection was based on DNA sequencing of the ribosomal intergenic spacer 2 (ITS2) marker. The importance of detecting the presence of overlooked digenean parasites in Mediterranean oysters is discussed. © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

The Dynamic Nature of Genomes Across the Tree of Life

Genomes are dynamic in lineages across the tree of life. Among bacteria and archaea, for example, DNA content varies through out life cycles, and nonbinary cell division in diverse lineages indicates the need for coordination of the inheritance of genomes. These observations contrast with the textbook view that bacterial and archaeal genomes are monoploid (i.e., single copied) and fixed both within species and throughout an individual\u27s lifetime. Here, we synthesize information on three aspects of dynamic genomes from exemplars representing a diverse array of bacterial and archaeal lineages: 1) ploidy level variation, 2) epigenetic mechanisms, and 3) life cycle variation. For example, the Euryarchaeota analyzed to date are all polyploid, as is the bacterium Epulopiscium that contains up to tens of thousands of copies of its genome and reproduces by viviparity. The bacterium Deinococcus radiodurans and the archaeon Halobacterium sp. NRC-1 can repair a highly fragmented genome within a few hours. Moreover, bacterial genera such as Dermocarpella and Planctomyces reproduce by fission (i.e., generating many cells from one cell) and budding, respectively, highlighting the need for regulation of genome inheritance in these lineages. Combining these data with our previous work on widespread genome dynamics among eukaryotes, we hypothesize that dynamic genomes are a rule rather than the exception across the tree of life. Further, we speculate that all domains may have the ability to distinguish germline from somatic DNA and that this ability may have been present the last universal common ancestor

The southernmost record of Felimida elegantula (Philippi, 1844) (Gastropoda: Nudibranchia)

The southernmost record of the Mediterranean nudibranch Felimida elegantula (Philippi, 1844) is reported here. A single specimen, with a colour pattern that hampered an easy morphological identification, was collected at the Kerkennah Islands (Tunisia). DNA-barcoding analysis (with the cytochrome c oxidase subunit I genetic marker) unambiguously confirmed its identification, and radular and anatomical features conformed with those previously described. With this record, the chromatic polymorphism of F. elegantula is demonstrated to be extremely large and the known range of the species is extended to the African coast of Tunisia

Piercing Fishes: Porin Expansion and Adaptation to Hematophagy in the Vampire Snail Cumia reticulata

4Cytolytic pore-forming proteins are widespread in living organisms, being mostly involved in both sides of the host–pathogen interaction, either contributing to the innate defense or promoting infection. In venomous organisms, such as spiders, insects, scorpions, and sea anemones, pore-forming proteins are often secreted as key components of the venom. Coluporins are pore-forming proteins recently discovered in the Mediterranean hematophagous snail Cumia reticulata (Colubrariidae), highly expressed in the salivary glands that discharge their secretion at close contact with the host. To understand their putative functional role, we investigated coluporins’ molecular diversity and evolutionary patterns. Coluporins is a well-diversified family including at least 30 proteins, with an overall low sequence similarity but sharing a remarkably conserved actinoporin-like predicted structure. Tracking the evolutionary history of the molluscan porin genes revealed a scattered distribution of this family, which is present in some other lineages of predatory gastropods, including venomous conoidean snails. Comparative transcriptomic analyses highlighted the expansion of porin genes as a lineage-specific feature of colubrariids. Coluporins seem to have evolved from a single ancestral porin gene present in the latest common ancestor of all Caenogastropoda, undergoing massive expansion and diversification in this colubrariid lineage through repeated gene duplication events paired with widespread episodic positive selection. As for other parasites, these findings are congruent with a “one-sided arms race,” equipping the parasite with multiple variants in order to broaden its host spectrum. Overall, our results pinpoint a crucial adaptive role for coluporins in the evolution of the peculiar trophic ecology of vampire snails.openopenGerdol, Marco; Cervelli, Manuela; Oliverio, Marco; Modica, Maria VittoriaGerdol, Marco; Cervelli, Manuela; Oliverio, Marco; Modica, Maria Vittori

Molecular phylogenetics of Haustrinae and Pagodulinae (Neogastropoda: Muricidae) with a focus on New Zealand species

We investigated the relationships of the muricid subfamilies Haustrinae, Pagodulinae and the genus Poirieria using a molecular phylogenetic approach on a dataset of three mitochondrial genes (12S, 16S and COI). These taxa form a well-supported clade within Muricidae. The phylogenetic analysis suggests that Poirieria is the sister group of Pagodulinae and that Axymene, Comptella, Pagodula, Paratrophon, Trophonella, Trophonopsis, Xymene, Xymenella, Xymenopsis and Zeatrophon are all worthy of genus-level rank within this subfamily. We propose the use of Enixotrophon for a group of species currently classified in Pagodula. The results also support a new taxonomic arrangement in Haustrinae

Cenozoic evolution of Muricidae (Mollusca, Neogastropoda) in the Southern Ocean, with the description of a new subfamily

Gastropods are among the most studied group in Antarctica, and taxa with an advanced status of systematic knowledge can be used as a model to study how oceanographic and climatic patterns shaped Recent faunal assemblages. Within the ongoing study of the muricid phylogeny, we have analysed molecular and morphological data from species traditionally ascribed to the muricid subfamily Trophoninae. Particularly, the availability of specimens collected in the Southern Ocean and surrounding basins allowed to demonstrate as the genera Pagodula, Xymenopsis, Xymene and Trophonella, which are traditionally classified in the Trophoninae, actually belong to a distinct lineage, for which the new subfamily Pagodulinae is herein introduced. We propose and discuss a possible framework for the origin and radiation of Antarctic muricid

Increase in knowledge of the marine gastropod fauna of Lebanon since the 19th century

We hereby review and update the current state of knowledge on the Lebanese gastropod biota based on published literature and the study of new samples. Review of 1543 published records yielded 237 gastropod taxa. New samples from the Lebanese coast yielded 2414 living specimens and 4003 empty shells, belonging to 188 taxa. Forty-six of the taxa are new records for the Lebanese fauna, bringing the gastropods known from Lebanon to 283 species. Literature records also included 71 nominal gastropod taxa based on type material from Lebanon, including 3 genera, 8 species, and 60 subspecific units. Of these, only 13 are retained as available. Of the 283 gastropod taxa known from Lebanon, 41 are aliens and 7 are cryptogenic. The majority of nonnative taxa were recorded only during the last decades, particularly from 1980 to 2019. Results from the present study question the common assumption that this region has extremely low native diversity. The flora and fauna of the Lebanese coast remain relatively unexplored and our data support the perception that several formerly abundant species have recently collapsed. Despite these advances, the lack of scientific data on biodiversity and community structure of Lebanese habitats and geographic zones is likely to hamper conservation actions and legal protection of critical species. We therefore recommend additional field and laboratory research to increase knowledge of both taxonomic composition and species’ distributions in Lebanon and elsewhere in the easternmost Mediterranean Sea

The spermidine analogue GC7 (N1-guanyl-1,7-diamineoheptane) induces autophagy through a mechanism not involving the hypusination of eIF5A

The exogenous administration of spermidine promotes longevity in many model organisms. It has been proposed that this anti-age activity of spermidine is related to this polyamine's ability to promote autophagy. Since spermidine is the substrate for the eIF5A post-translational modification by hypusination, we asked ourselves whether mature eIF5A may represent the link between spermidine and autophagy induction. To test this hypothesis, we inhibited the conversion of native eIF5A by a pharmacological approach, using the N1-guanyl-1,7-diamineoheptane (GC7), a spermidine analogue which competitively and reversibly inhibits deoxyhypusine synthase (DHS). In addition, we also employed genetic approaches by ablating both the eIF5A protein itself and DHS, the rate limiting enzyme catalyzing the conversion of lysine to hypusine. Collectively the data presented in this study demonstrate that the mature eIF5A (hypusinated form) is not involved in the autophagic pathway and that the inhibitor of DHS, GC7, produces off-target effect(s) resulting in marked induction of basal autophagy. These data are relevant in light of the fact that GC7 is considered a potent and selective inhibitor of DHS and is a potential candidate drug for cancer, diabetes and HIV therapy