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Marine Environmental Research Jan 2024Corals provide a complex 3D framework that offers habitat to diverse coral reef fauna. However, future reefs are likely to experience reduced coral abundance. Sponges...
Corals provide a complex 3D framework that offers habitat to diverse coral reef fauna. However, future reefs are likely to experience reduced coral abundance. Sponges have been proposed as one potential winner on future coral reefs, but little is known of how they contribute to reef 3D structure. Given the ecological importance of structural complexity, it is critical to understand how changes in the abundance of structure-building organisms will affect the three-dimensional properties of coral reefs. To investigate the potentially important functional role of coral reef sponges as providers of structural complexity, we compared the structural complexity of coral- and sponge-dominated areas of an Indonesian coral reef, using 3D photogrammetry at a 4 m spatial scale. Structural complexity of 31 4 m quadrats was expressed as rugosity indicating reef contour complexity (R), vector dispersion indicating heterogeneity of angles between reef surfaces (1/k), and fractal dimension indicating geometrical complexity at five different spatial scales between 1 and 120 cm (D). Quadrats were identified as high- or low-complexity using hierarchical clustering based on the complexity metrics. At high structural complexity, coral- and sponge-dominated quadrats were similar in terms of R and 1/k. However, smallest-scale refuge spaces (1-5 cm) were more abundant in coral-dominated quadrats, whereas larger scale refuge spaces (30-60 cm) were more abundant in sponge-dominated quadrats. Branching and massive corals contributed the most to structural complexity in coral-dominated quadrats, and barrel sponges in sponge-dominated quadrats. We show that smaller-scale refugia (1-5 cm) are reduced on sponge-dominated reefs at the spatial scale considered here (4 m), with potential negative implications for smaller reef fauna.
Topics: Animals; Coral Reefs; Ecosystem; Anthozoa
PubMed: 37979404
DOI: 10.1016/j.marenvres.2023.106254 -
The Journal of Experimental Biology Dec 2023Sensory perception of chemical threats coming from an organism's environment relies on the coordination of numerous receptors and cell types. In many cases, the...
Sensory perception of chemical threats coming from an organism's environment relies on the coordination of numerous receptors and cell types. In many cases, the physiological processes responsible for driving behavioral responses to chemical cues are poorly understood. Here, we investigated the physiological response of fish to an unpalatable compound, formoside, which is employed as a chemical defense by marine sponges. Construction of fluorescent probe derivatives of formoside allowed visualization of this chemical defense molecule in vivo, interacting with the cells and tissues of the early larvae of a model predator, the zebrafish (Danio rerio). This revealed the precise chemosensory structures targeted by formoside to be in the taste buds and olfactory epithelium of developing zebrafish. Mechanosensory neuromasts were also targeted. This study supports the involvement of a previously identified co-receptor in detection of the chemical defense and provides a springboard for the long-term goal of identification of the cellular receptor of formoside. Extension of this approach to other predators and chemical defenses may provide insight into common mechanisms of chemoreception by predators as well as common strategies of chemical defense employed by prey.
Topics: Animals; Zebrafish; Porifera; Glycosides; Triterpenes; Predatory Behavior
PubMed: 37975309
DOI: 10.1242/jeb.246246 -
Scientific Reports Nov 2023Epithelial wound healing involves the collective responses of many cells, including those at the wound margin (marginal cells) and those that lack direct contact with...
Epithelial wound healing involves the collective responses of many cells, including those at the wound margin (marginal cells) and those that lack direct contact with the wound (submarginal cells). How these responses are induced and coordinated to produce rapid, efficient wound healing remains poorly understood. Extracellular ATP (eATP) is implicated as a signal in epithelial wound healing in vertebrates. However, the role of eATP in wound healing in vivo and the cellular responses to eATP are unclear. Almost nothing is known about eATP signaling in non-bilaterian metazoans (Cnidaria, Ctenophora, Placozoa, and Porifera). Here, we show that eATP promotes closure of epithelial wounds in vivo in the cnidarian Clytia hemisphaerica (Clytia) indicating that eATP signaling is an evolutionarily ancient strategy in wound healing. Furthermore, eATP increases F-actin accumulation at the edges of submarginal cells. In Clytia, this indicates eATP is involved in coordinating cellular responses during wound healing, acting in part by promoting actin remodeling in cells at a distance from the wound. We also present evidence that eATP activates a cation channel in Clytia epithelial cells. This implies that the eATP signal is transduced through a P2X receptor (P2XR). Phylogenetic analyses identified four Clytia P2XR homologs and revealed two deeply divergent major branches in P2XR evolution, necessitating revision of current models. Interestingly, simple organisms such as cellular slime mold appear exclusively on one branch, bilaterians are found exclusively on the other, and many non-bilaterian metazoans, including Clytia, have P2XR sequences from both branches. Together, these results re-draw the P2XR evolutionary tree, provide new insights into the origin of eATP signaling in wound healing, and demonstrate that the cytoskeleton of submarginal cells is a target of eATP signaling.
Topics: Animals; Phylogeny; Hydrozoa; Wound Healing; Signal Transduction; Adenosine Triphosphate
PubMed: 37914720
DOI: 10.1038/s41598-023-45424-5 -
Biomolecules Oct 2023The larval stages of the tobacco budworm, (Fabricius) (Lepidoptera: Noctuidae), are parasitized by the endophagous parasitoid wasp, (Viereck) (Hymenoptera:...
The larval stages of the tobacco budworm, (Fabricius) (Lepidoptera: Noctuidae), are parasitized by the endophagous parasitoid wasp, (Viereck) (Hymenoptera: Braconidae). During the injections of eggs, this parasitoid wasp also injects into the host body the secretion of the venom gland and the calyx fluid, which contains a polydnavirus ( BracoVirus: BV) and the Ovarian calyx fluid Proteins (OPs). The effects of the OPs on the host immune system have recently been described. In particular, it has been demonstrated that the OPs cause hemocytes to undergo a number of changes, such as cellular oxidative stress, actin cytoskeleton modifications, vacuolization, and the inhibition of hemocyte encapsulation capacity, which results in both a loss of hemocyte functionality and cell death. In this study, by using a combined transcriptomic and proteomic analysis, the main components of ovarian calyx fluid proteins were identified and their possible role in the parasitic syndrome was discussed. This study provides useful information to support the analysis of the function of ovarian calyx fluid proteins, to better understand parasitization success and for a more thorough understanding of the components of ovarian calyx fluid proteins and their potential function in combination with other parasitoid factors.
Topics: Animals; Transcriptome; Proteomics; Wasps; Moths; Larva; Porifera
PubMed: 37892230
DOI: 10.3390/biom13101547 -
Marine Drugs Sep 2023The adamantane structure of arsenicin A and nor-adamantane structures of arsenicins B-D have gained attention as unique natural polyarsenicals, as well as hits showing...
The adamantane structure of arsenicin A and nor-adamantane structures of arsenicins B-D have gained attention as unique natural polyarsenicals, as well as hits showing promising anticancer activity. The purpose of this study is to apply the predictive power of NMR DFT calculations in order to identify a valid tool to be used in the structural elucidation of similar molecules. H- and C-NMR chemical shifts of twelve natural and synthetic polyarsenical analogs were calculated and validated by comparison with experimental data acquired in CDCl solutions, in regard to mean absolute error (MAE) values under various combinations of two methods (GIAO and CSGT), four functionals and five basis sets, also considering relativistic effects. The best computational approaches are highlighted for predicting the chemical shifts of H and C nuclei and (H,H) coupling constants in the series of O- and S-polyarsenicals. This comprehensive analysis contributes to making NMR spectroscopy appealing for the structural elucidation of such molecules, contrary to the first structural elucidation of natural arsenicin A, in which the experimental NMR analysis was limited by the poor presence of proton and carbon atoms in its structure and by the shortage of reference data.
Topics: Animals; Magnetic Resonance Spectroscopy; Arsenicals; Porifera; Protons; Adamantane
PubMed: 37888446
DOI: 10.3390/md21100511 -
Marine Drugs Sep 2023Eight new scalarane sesterterpenes, phyllofenones F-M (-), together with two known analogues, carteriofenones B and A (-), were isolated from the marine sponge...
Eight new scalarane sesterterpenes, phyllofenones F-M (-), together with two known analogues, carteriofenones B and A (-), were isolated from the marine sponge collected from the South China Sea. The structures of these compounds were determined based on extensive spectroscopic and quantum chemical calculation analysis. The antibacterial and cytotoxic activity of these compounds was evaluated. Among them, only compounds and displayed weak inhibitory activity against and , with MIC values of 16 μg/mL and 8 μg/mL, respectively. Compounds - exhibited cytotoxic activity against the HeLa, HCT-116, H460, and SW1990 cancer cell lines, with IC values ranging from 3.4 to 19.8 μM.
Topics: Animals; Humans; Sesterterpenes; Porifera; Magnetic Resonance Spectroscopy; Antineoplastic Agents; HeLa Cells; Escherichia coli; Molecular Structure
PubMed: 37888442
DOI: 10.3390/md21100507 -
Frontiers in Neural Circuits 2023Interkingdom signalling within a holobiont allows host and symbionts to communicate and to regulate each other's physiological and developmental states. Here we show...
Interkingdom signalling within a holobiont allows host and symbionts to communicate and to regulate each other's physiological and developmental states. Here we show that a suite of signalling molecules that function as neurotransmitters and neuromodulators in most animals with nervous systems, specifically dopamine and trace amines, are produced exclusively by the bacterial symbionts of the demosponge . Although sponges do not possess a nervous system, expresses rhodopsin class G-protein-coupled receptors that are structurally similar to dopamine and trace amine receptors. When sponge larvae, which express these receptors, are exposed to agonists and antagonists of bilaterian dopamine and trace amine receptors, we observe marked changes in larval phototactic swimming behaviour, consistent with the sponge being competent to recognise and respond to symbiont-derived trace amine signals. These results indicate that monoamines synthesised by bacterial symbionts may be able to influence the physiology of the host sponge.
Topics: Animals; Dopamine; Porifera; Amines; Neurotransmitter Agents; Communication
PubMed: 37841893
DOI: 10.3389/fncir.2023.1250694 -
Proceedings of the National Academy of... Oct 2023In patients blinded by geographic atrophy, a subretinal photovoltaic implant with 100 µm pixels provided visual acuity closely matching the pixel pitch. However, such...
In patients blinded by geographic atrophy, a subretinal photovoltaic implant with 100 µm pixels provided visual acuity closely matching the pixel pitch. However, such flat bipolar pixels cannot be scaled below 75 µm, limiting the attainable visual acuity. This limitation can be overcome by shaping the electric field with 3-dimensional (3-D) electrodes. In particular, elevating the return electrode on top of the honeycomb-shaped vertical walls surrounding each pixel extends the electric field vertically and decouples its penetration into tissue from the pixel width. This approach relies on migration of the retinal cells into the honeycomb wells. Here, we demonstrate that majority of the inner retinal neurons migrate into the 25 µm deep wells, leaving the third-order neurons, such as amacrine and ganglion cells, outside. This enables selective stimulation of the second-order neurons inside the wells, thus preserving the intraretinal signal processing in prosthetic vision. Comparable glial response to that with flat implants suggests that migration and separation of the retinal cells by the walls does not cause additional stress. Furthermore, retinal migration into the honeycombs does not negatively affect its electrical excitability, while grating acuity matches the pixel pitch down to 40 μm and reaches the 27 μm limit of natural resolution in rats with 20 μm pixels. These findings pave the way for 3-D subretinal prostheses with pixel sizes of cellular dimensions.
Topics: Humans; Rats; Animals; Visual Prosthesis; Prosthesis Implantation; Retina; Vision, Ocular; Porifera; Retinal Neurons; Electric Stimulation
PubMed: 37831740
DOI: 10.1073/pnas.2307380120 -
Antonie Van Leeuwenhoek Dec 2023Family Chrysopidae is known to harbor specific gut yeasts. However, no studies have been conducted outside of a limited number of these green lacewing species, and the...
Family Chrysopidae is known to harbor specific gut yeasts. However, no studies have been conducted outside of a limited number of these green lacewing species, and the diversity of yeasts in the family as a whole is not known. Therefore, we collected 58 Chrysopidae adults (9 species, 6 genera, 2 subfamilies) in Japan and isolated yeasts from all individuals. The results showed for the first time that not only subfamily Chrysopinae but also subfamily Apochrysinae have gut yeasts. We obtained 58 yeast isolates (one from each host individual), all of which were of the genus Metschnikowia. 28S rDNA- and ITS-based phylogenetic analysis showed that the isolates were divided into three clades, designated clade I, II, and III. Clade I contains two previously described Chrysopidae gut yeasts (M. picachoensis and M. pimensis) as well as a one of our new species named M. shishimaru. Clade II is a new clade, with at least two new species named M. kenjo and M. seizan. Clade III contains the previously described species M. noctiluminum, a Chrysopidae gut yeast, and one of our isolate (We have not described it as new species). However, the phylogenetic relationship between our isolate and M. noctiluminum was unclear. These results indicate that the Japanese Chrysopidae gut yeasts consist mainly of three undescribed species and that they are more unique than those found in previous surveys. The results of this study indicate that Chrysopidae gut yeasts are more diverse than previously thought and should be investigated in various geographical regions in the future.
Topics: Humans; Animals; Metschnikowia; Phylogeny; Japan; Yeasts; Porifera
PubMed: 37755530
DOI: 10.1007/s10482-023-01887-0 -
Marine Drugs Sep 2023Marine sponges usually host a wide array of secondary metabolites that play crucial roles in their biological interactions. The factors that influence the intraspecific...
Marine sponges usually host a wide array of secondary metabolites that play crucial roles in their biological interactions. The factors that influence the intraspecific variability in the metabolic profile of organisms, their production or ecological function remain generally unknown. Understanding this may help predict changes in biological relationships due to environmental variations as a consequence of climate change. The sponge is common in shallow rocky bottoms of the Antarctic Peninsula and is known to produce diterpenes that are supposed to have defensive roles. Here we used GC-MS to determine the major diterpenes in two populations of from two islands, Livingston and Deception Island (South Shetland Islands). To assess the potential effect of heat stress, we exposed the sponge in aquaria to a control temperature (similar to local), heat stress (five degrees higher) and extreme heat stress (ten degrees higher). To test for defence induction by predation pressure, we exposed the sponges to the sea star and the amphipod . Seven major diterpenes were isolated and identified from the samples. While six of them were already reported in the literature, we identified one new aplysulphurane derivative that was more abundant in the samples from Deception Island, so we named it deceptionin (). The samples were separated in the PCA space according to the island of collection, with 9,11-dihydrogracilin A () being more abundant in the samples from Livingston, and deceptionin () in the samples from Deception. We found a slight effect of heat stress on the diterpene profiles of , with tetrahydroaplysulphurin-1 () and the gracilane norditerpene being more abundant in the group exposed to heat stress. Predation pressure did not seem to influence the metabolite production. Further research on the bioactivity of secondary metabolites, and their responses to environmental changes will help better understand the functioning and fate of the Antarctic benthos.
Topics: Animals; Terpenes; Antarctic Regions; Predatory Behavior; Amphipoda; Bandages; Porifera; Starfish
PubMed: 37755112
DOI: 10.3390/md21090499