43 research outputs found

    Project "Biodiversity MARE Tricase": a biodiversity inventory of the coastal area of Tricase (Ionian Sea, Italy) – Mollusca: Heterobranchia

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    The marine biodiversity of the Tricase coastal area (Ionian Sea, Italy) was investigated at the MARE Outpost (Avamposto MARE) between 2016 and 2017, with the help of citizen scientists and trained taxonomists. Among the most interesting groups encountered, heterobranch molluscs deserve a special mention. Altogether, 268 specimens were ascribed to this group and referred to 49 taxa. Notwithstanding the extensive literature on Mediterranean heterobranchs, two species proved to be new to the Italian coasts, the records of eight species represented their easternmost sightings in the Mediterranean Sea, and 13 taxa represented new records for the Ionian Sea. In addition, several feeding habits and phenological events were new to science. Although the European Union's Marine Strategy Framework Directive lists "Biodiversity is maintained" as the first descriptor in achieving "Good Environmental Status", our results highlighted the presence of conspicuous gaps in the knowledge of species distribution, taxonomy and ecology of heterobranch molluscs, indicating the necessity of even small-scale species checklists to understand biodiversity changes in worldwide biota

    La fauna di spugne di Porto Tricase, Canale d\u2019Otranto

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    This study deals with the sponge fauna of Porto Tricase, Strait of Otranto, Ionian Sea. The present sponge fauna was compared with that described by Pulitzer-Finali more than 40 years ago. The main results are three new findings for the Ionian Sea, a second record for the Mediterranean Sea and a likely new sponge species

    Shallow-water sponge grounds along the Apulian coast (central Mediterranean Sea)

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    Sponge grounds are complex three-dimensional benthic habitats dominated by sponges. These sponge-dominated assemblages have been reported worldwide, from the intertidal zone to the deep sea. In shallow euphotic waters, dense sponge aggregations have been mainly found in tropical areas, and their presence is in some cases related to environmental degradation and coral decline. The Mediterranean Sea is globally recognised as a biodiversity hotspot, where light-exposed rocky reefs are typically dominated by photophilous algae. However, high local anthropogenic pressures, coupled with climate change, are leading to the reorganisation of benthic communities and the occurrence of regime shifts in several areas. Here we report the first description of unusual, shallow-water sponge grounds in Mediterranean light-exposed rocky reefs, in an area previously impacted by the destructive date-mussel fishery. These assemblages, found along the Apulian coast (central Mediterranean Sea), are now (2017) characterised by a mean coverage of sponges ranging between 3% and 33%, with maximum values up to 85%. Variation in the structure of assemblages and in the abundance of individual taxa between depths has been tested by multivariate and univariate techniques. The spatial characterisation has been complemented with the taxonomic analysis of the sponge assemblages, which resulted in the identification of 14 sponge taxa. These findings are compared with results of previous research in the same area and discussed with particular reference to the potential variables involved in sponge dominance and spatial distribution in the present system and elsewhere

    3D-reconstruction of the structural association between triads and mitochondria in skeletal fibers

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    Skeletal muscle can vary considerably its metabolism during activity. Since cell metabolism is controlled by Ca2Ăľ signals, the precise positioning of mitochondria next to the Ca2Ăľ release sites may be of great importance for the proper functioning of muscle fibers. In adult skeletal muscle, mitochondria are mostly located in proximity of triads, structures formed by the close apposition of SR and Ttubules, which mediate excitation-contraction coupling releasing Ca2Ăľ during muscle activation (calcium release units, CRUs). Using electron microscopy, we have identified short strands (or tethers, ~10 nm long) connecting specifically the outer membrane of mitochondria to the SR, on the opposite side to the T-tubules (Boncompagni and Protasi, 2007; Biophys J. 92:A313). Tethers frequency increases during post-natal maturation, suggesting that these structures may have a crucial role in the progressive targeting of mitochondria next to triads. The SR-mitochondria association is sufficiently strong that treatment of FDB fibers with hypotonic solution results in stretching of the SR vesicle in correspondence of tethers. Using electron tomography, we have reconstructed the tri-dimensional architecture of triad/mitochondria interface providing additional information on the structural relationship between these two myoplasmic organelles. SR surrounds the mitochondria with lateral sacks/tubules and it is closely associated to it (tethered) also in mitochondrial regions closer to the Z line, on the side opposite to the triad. The molecular nature of the physical linkage is not yet identified and for now we can only speculate as to the possible structural importance that these small bridges may have in holding SR and mitochondria together

    On the larva and the zooid of the pterobranch Rhabdopleura recondita Beli, Cameron and Piraino, 2018 (Hemichordata, Graptolithina)

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    Hemichordates (Enteropneusta and Pterobranchia) belong to a small deuterostome invertebrate group that may offer insights on the origin and evolution of the chordate nervous system. Among them, the colonial pterobranch Rhabdopleuridae are recognized as living representatives of Graptolithina, a taxon with a rich fossil record. New information is provided here on the substrate selection and the life cycle of Rhabdopleura recondita Beli, Cameron and Piraino, 2018, and for the first time, we describe the nervous system organization of the larva and the adult zooid, as well as the morphological, neuroanatomical and behavioural changes occurring throughout metamorphosis. Immunohistochemical analyses disclosed a centralized nervous system in the sessile adult zooid, characterized by different neuronal subsets with three distinct neurotransmitters, i.e. serotonin, dopamine and RFamide. The peripheral nervous system comprises GABA-, serotonin-, and dopamine-immunoreactive cells. These observations support and integrate previous neuroanatomical findings on the pterobranch zooid of Cephalodiscus gracilis. Indeed, this is the first evidence of dopamine, RFamide and GABA neurotransmitters in hemichordates pterobranchs. In contrast, the lecithotrophic larva is characterized by a diffuse basiepidermal plexus of GABAergic cells, coupled with a small group of serotonin-immunoreactive cells localized in the characteristic ventral depression. It is envisaged the use of R. recondita as a novel and easily accessible hemichordate model organism to shed light on the evolution of hemichordates and more generally on the origin of deuterostome developmental mechanisms

    OPA1 controls apoptotic cristae remodeling independently from mitochondrial fusion

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    Mitochondria amplify activation of caspases during apoptosis by releasing cytochrome c and other cofactors. This is accompanied by fragmentation of the organelle and remodeling of the cristae. Here we provide evidence that Optic Atrophy 1 (OPA1), a profusion dynamin-related protein of the inner mitochondrial membrane mutated in dominant optic atrophy, protects from apoptosis by preventing cytochrome c release independently from mitochondrial fusion. OPA1 does not interfere with activation of the mitochondrial “gatekeepers” BAX and BAK, but it controls the shape of mitochondrial cristae, keeping their junctions tight during apoptosis. Tightness of cristae junctions correlates with oligomerization of two forms of OPA1, a soluble, intermembrane space and an integral inner membrane one. The proapoptotic BCL-2 family member BID, which widens cristae junctions, also disrupts OPA1 oligomers. Thus, OPA1 has genetically and molecularly distinct functions in mitochondrial fusion and in cristae remodeling during apoptosis

    OPA1 controls apoptotic cristae remodeling independently from mitochondrial fusion

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    Mitochondria amplify activation of caspases during apoptosis by releasing cytochrome c and other cofactors. This is accompanied by fragmentation of the organelle and remodeling of the cristae. Here we provide evidence that Optic Atrophy 1 (OPA1), a profusion dynamin-related protein of the inner mitochondrial membrane mutated in dominant optic atrophy, protects from apoptosis by preventing cytochrome c release independently from mitochondrial fusion. OPA1 does not interfere with activation of the mitochondrial "gatekeepers" BAX and BAK, but it controls the shape of mitochondrial cristae, keeping their junctions tight during apoptosis. Tightness of cristae junctions correlates with oligomerization of two forms of OPA1, a soluble, intermembrane space and an integral inner membrane one. The proapoptotic BCL-2 family member BID, which widens cristae junctions, also disrupts OPA1 oligomers. Thus, OPA1 has genetically and molecularly distinct functions in mitochondrial fusion and in cristae remodeling during apoptosis.status: publishe

    Axenic culture of a candidate division TM7 bacterium from the human oral cavity and biofilm interactions with other oral bacteria

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    Taken by U.S. Army medic Charles Tweel in 1971, this photograph shows Rusty Hide (far left) and two other Americans at Camp Evans during the Vietnam War. This photograph is part of the Charles Tweel Collection (AV 324) at the Ohio History Connection. Charles Tweel grew up in Columbus, Ohio, and attended The Ohio State University. After graduation in 1968, he enlisted in the U.S. Army as a non-combatant, first training as a medic at Fort Sam Huston, followed by nine months of additional training at Valley Forge General Hospital in Phoenixville, Pennsylvania. He finished his training as a Specialist 3 and 91C, MOS, and went on to serve in Bamberg, Germany, with combat engineers for one year. In January 1971, Tweel served in Vietnam with the Headquarters and Headquarters Company, 2nd Battalion (Air Mobile), 506th Infantry Regiment, 101st Airborne Division, based out of Camp Evans near Phu Bai, north of Hue, until December of that year. Tweel spent most of his service on various firebases as the medic in charge, and occasionally shared firebases with South Vietnamese soldiers. He also visited MedCAP stations (Medical Civic Action Programs) where he treated civilians. Tweel received the Bronze Star Medal for meritorious achievement, and was promoted to Specialist 5 in 1971. After discharge from the Army, he went to medical school and was in private practice as a family practitioner from 1979-2016, and now works part-time in inner city medical clinics in Columbus, Ohio, and Charleston, South Carolina
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