Alternative neural systems: What is a neuron? (Ctenophores, sponges and placozoans)

Frontiers in Cell and Developmental Biology, Journal Year: 2022, Volume and Issue: 10

Published: Dec. 23, 2022

How to make a neuron, synapse, and neural circuit? Is there only one 'design' for architecture with universally shared genomic blueprint across species? The brief answer is "No." Four early divergent lineages from the nerveless common ancestor of all animals independently evolved distinct neuroid-type integrative systems. One these subset nets in comb jellies unique synapses; second lineage well-known Cnidaria + Bilateria; two others are non-synaptic neuroid systems sponges placozoans. By integrating scRNA-seq microscopy data, we revise definition neurons as synaptically-coupled polarized highly heterogenous secretory cells at top behavioral hierarchies learning capabilities. This physiological (not phylogenetic) separates 'true' non-synaptically gap junction-coupled executing more stereotyped behaviors. Growing evidence supports hypothesis multiple origins synapses. Thus, many non-bilaterian bilaterian neuronal classes, circuits or considered functional rather than genetic categories, composed non-homologous cell types. In summary, little-explored examples convergent evolution representatives branching metazoans provide conceptually novel microanatomical architectures controls prospects neuro-engineering synthetic biology.

Language: Английский

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Adapting to the Abyss: Passive Ventilation in the Deep-Sea Glass Sponge Euplectella aspergillum

Physical Review Letters, Journal Year: 2024, Volume and Issue: 132(20)

Published: May 16, 2024

We analyze the flow physics inside body cavity and downstream deep-sea glass sponge Euplectella aspergillum. provide evidence that helical skeletal motifs of give rise to a rich fluid dynamic field, allowing organism scavenge from bottom sea promoting spontaneous, organized vertical within its toward osculum. Our analysis points at functional adaptation organism, which can passively divert through osculum in unfavorable, low ambient currents, with no need for active pumping, potential repercussions ecology, as well design chemical reactors, air-treatment units, civil aeronaval structures.Received 6 March 2023Accepted 9 April 2024DOI:https://doi.org/10.1103/PhysRevLett.132.208402© 2024 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBiological dynamicsFlow-structure interactionsVortex interactionsTechniquesLattice-Boltzmann methodsFluid DynamicsPhysics Living Systems

Language: Английский

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Looking for the sponge loop: analyses of detritus on a Caribbean forereef using stable isotope and eDNA metabarcoding techniques

PeerJ, Journal Year: 2024, Volume and Issue: 12, P. e16970 - e16970

Published: Feb. 23, 2024

Coral reefs are biodiverse ecosystems that rely on trophodynamic transfers from primary producers to consumers through the detrital pathway. The sponge loop hypothesis proposes sponges consume dissolved organic carbon (DOC) and produce large quantities of detritus coral reefs, with this turn-over approaching daily gross production reef ecosystem. In study, we collected samples in epilithic algal matrix (EAM) potential sources over two seasons forereef at Carrie Bow Cay, Belize. We chose location maximize likelihood finding support for because Caribbean have higher abundances than other tropical worldwide Mesoamerican barrier is an archetypal used stable isotope analyses eDNA metabarcoding determine composition detritus. determined EAM was derived a variety benthic pelagic sources, (micro- macroalgae) as major contributors metazoans (Arthropoda, Porifera, Cnidaria, Mollusca) minor contributors. None species reportedly were present cnidarian signature dominated by octocorals, scarcity hard corals. also varied seasonally. negligible contribution contrasts pathway originally proposed hypothesis. findings indicate mix calmer summer primarily more turbulent spring.

Language: Английский

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ATP and glutamate coordinate contractions in the freshwater sponge Ephydatia muelleri

Journal of Experimental Biology, Journal Year: 2025, Volume and Issue: 228(3)

Published: Feb. 1, 2025

ABSTRACT Sponges (phylum Porifera) are an early diverging animal lineage without nervous and muscular systems, yet they able to produce coordinated whole-body contractions in response disturbances. Little is known about the underlying signalling mechanisms coordinating such responses. Previous studies demonstrated that sponges respond specifically chemicals as l-glutamate γ-amino-butyric acid (GABA), which trigger prevent contractions, respectively. Genes for purinergic P2X-like receptors present several sponge genomes, leading us ask whether ATP works with glutamate coordinate it does other systems. Using pharmacological approaches on freshwater Ephydatia muelleri, we show involved contractions. Bath application of caused a rapid, sustained expansion excurrent canals dose-dependent manner. Complete occurred when was added presence apyrase, enzyme hydrolyses ATP. Application ADP, first metabolic product hydrolysis, triggered complete whereas AMP, subsequent metabolite, did not response. Blocking from binding activating P2X pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic (PPADS) prevented both glutamate- ATP-triggered suggesting downstream glutamate. Bioinformatic analysis revealed two receptor sequences, one groups vertebrate receptors. Altogether, our results confirm by sponge.

Language: Английский

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A morphological cell atlas of the freshwater sponge Ephydatia muelleri with key insights from targeted single-cell transcriptomes

EvoDevo, Journal Year: 2025, Volume and Issue: 16(1)

Published: Feb. 14, 2025

How animal cell types, tissues, and regional body plans arose is a fundamental question in EvoDevo. Many current efforts attempt to link genetic information the morphology of cells, tissues regionalization using single-cell sequencing populations. However, lack in-depth understanding non-bilaterian animals remains considerable block transitions between bilaterian cells tissues. Sponges (Porifera), one earliest diverging phyla, pose particular challenge this endeavour, because their mouths, gut, conventional muscle nervous systems. With goal help bridge gap, we have studied morphology, behaviour transcriptomics tissue types an easily accessible well-studied species freshwater sponge, Ephydatia muelleri. New features described here include: polarized external epithelium, new contractile sieve that forms entry incurrent canals, motile cilia on apopyle at exit choanocyte chambers, non-motile excurrent canals oscula. Imaging vivo shows distinct behavioural characteristics mesohyl. Transcriptomic phenotypes three (cystencytes, choanocytes archaeocytes) captured live indicate cell-type transcriptomes are distinct. Importantly, individual archaeocytes show range transcriptomic which supported by expression different genes subsets type. In contrast, all five sampled revealed highly uniform with significantly fewer expressed than other types. Our study sponges whose diversity both functionally complex, but together enable like metazoans, sense respond stimuli.

Language: Английский

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Placozoan secretory cell types implicated in feeding, innate immunity and regulation of behavior

PLoS ONE, Journal Year: 2025, Volume and Issue: 20(4), P. e0311271 - e0311271

Published: April 22, 2025

Placozoa are millimeter-sized, flat, irregularly shaped ciliated animals that crawl on surfaces in warm oceans feeding biofilms, which they digest externally. They stand out from other due to their simple body plans. lack organs, cavities, muscles and a nervous system have only seven broadly defined morphological cell types, each with unique distribution. Analyses of single transcriptomes four species placozoans revealed greater diversity secretory types than evident studies, but the locations many these new were unknown it was unclear represent. Furthermore, there contradictions between conclusions previous studies RNAseq studies. To address issues, we used mRNA probes for genes encoding products expressed different metacells Trichoplax adhaerens localize cells whole mounts dissociated cultures, where features could be visualized identified. The nature functions granules further investigated electron microscopic techniques by imaging secretion live during episodes. We found two participate disintegrating prey, one resembling lytic type mammals another combining zymogen gland enterocytes. identified epithelial expressing glycoproteins or short peptides implicated defense. located peptidergic mucocytes. Our findings reveal mechanisms use feed protect themselves pathogens clues about neuropeptidergic signaling. compare placozoan animal phyla gain insight general evolutionary trends diversification, as well pathways leading emergence synapomorphies.

Language: Английский

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In vitro effects of a plastic additive (DEHP) on contraction dynamics of Hymeniacidon heliophila (Demospongiae: Halichondrida)

Marine Environmental Research, Journal Year: 2025, Volume and Issue: 210, P. 107268 - 107268

Published: June 2, 2025

Language: Английский

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Eating and Cognition in Two Animals without Neurons: Sponges and Trichoplax

Biological Theory, Journal Year: 2024, Volume and Issue: unknown

Published: June 13, 2024

Abstract Eating is a fundamental behavior in which all organisms must engage order to procure the material and energy from their environment that they need maintain themselves. Since controlling eating requires procuring, processing, assessing information, it constitutes cognitive activity provides productive domain for pursuing biology as proposed by Ladislav Kováč. In agreement with Kováč, we argue cognition fundamentally grounded chemical signaling processing. To support this thesis, adopt Cisek’s strategy of phylogenetic refinement, focusing on two animal phyla, Porifera Placozoa, do not have neurons, muscles, or an alimentary canal, but nonetheless coordinate cells multiple types eat. We review what research has revealed so far about how these animals gather process information control behavior.

Language: Английский

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Sponge functional roles in a changing world

Advances in marine biology, Journal Year: 2023, Volume and Issue: unknown, P. 27 - 89

Published: Jan. 1, 2023

Language: Английский

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A carbon cycling model shows strong control of seasonality and importance of sponges on the functioning of a northern Red Sea coral reef

Coral Reefs, Journal Year: 2023, Volume and Issue: 42(2), P. 367 - 381

Published: Jan. 24, 2023

Abstract Coral reefs in the northern Red Sea experience strong seasonality. This affects reef carbon (C) cycling, but ecosystem-wide quantification of C fluxes such is limited. study quantified seasonal community with incubations. Resulting data were then incorporated into linear inverse models (LIM). For spring, additional sponge incubation results allowed for unique assessment contribution sponges to cycling. The coral ecosystem was heterotrophic throughout all seasons as gross primary production (GPP; 136–200, range means mmol m −2 d −1 ) less than respiration (R; 192–279), and balanced by import organic (52–100), 88‒92% which being dissolved (DOC). Hard GPP (74–110) R (100–137), well pelagic bacteria DOC uptake (58–101) (42–86), largest across seasons. least spring (highest irradiance) (GPP:R 0.81), most summer fall higher water temperatures (0.68 0.60, respectively). Adding model increased (247 ± 8 without 353 13 (mean SD)). Sponges this demand primarily (105 6, 97% cryptic sponges). rate comparable (104 5) placing among dominant cycling groups reef.

Language: Английский

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