ArticlePloS one2018
Cells containing aragonite crystals mediate responses to gravity in Trichoplax adhaerens (Placozoa), an animal lacking neurons and synapses.
Article in PloS one, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers.
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Who cites it
25 citing papers in PubMed, 61 citations in OpenAlex.
- An extinct clade of the basal Epitheliozoa: phylogenetic position and implication of the enigmatic Cambrian chancelloriids.Communications biology · 2025Article
- Evolution of iGluR ligand specificity, polyamine regulation, and ion selectivity inferred from a placozoan epsilon receptor.Communications biology · 2025Article
- Tolerance of Placozoa for temperate climates: Evidence for known and new placozoan clades in the southern waters of Australia.PloS one · 2025Article
- Placozoan secretory cell types implicated in feeding, innate immunity and regulation of behavior.PloS one · 2025Article
- Coordinated cellular behavior regulated by epinephrine neurotransmitters in the nerveless placozoa.Nature communications · 2024Article
- Genomic and single-cell analyses reveal genetic signatures of swimming pattern and diapause strategy in jellyfish.Nature communications · 2024Article
- Parallel evolution of gravity sensing.Frontiers in cell and developmental biology · 2024Article
- Chemical cognition: chemoconnectomics and convergent evolution of integrative systems in animals.Animal cognition · 2023Article
- Function and phylogeny support the independent evolution of an ASIC-like Deg/ENaC channel in the Placozoa.Communications biology · 2023Article
- Acorn worm ossicle ultrastructure and composition and the origin of the echinoderm skeleton.Royal Society open science · 2022Article
- Studying Placozoa WBR in the Simplest Metazoan Animal, Trichoplax adhaerens.Methods in molecular biology (Clifton, N.J.) · 2022Article
- Alternative neural systems: What is a neuron? (Ctenophores, sponges and placozoans).Frontiers in cell and developmental biology · 2022Article
- Expanding of Life Strategies in Placozoa: Insights From Long-Term Culturing ofFrontiers in cell and developmental biology · 2022Article
- Placozoan fiber cells: mediators of innate immunity and participants in wound healing.Scientific reports · 2021Article
- Hidden cell diversity in Placozoa: ultrastructural insights from Hoilungia hongkongensis.Cell and tissue research · 2021Article
- An Implanted Vestibular Prosthesis Improves Spatial Orientation in Animals with Severe Vestibular Damage.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2021Article
- Neural versus alternative integrative systems: molecular insights into origins of neurotransmitters.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2021Review
- Reafference and the origin of the self in early nervous system evolution.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2021Review
- Microscopy Studies of Placozoans.Methods in molecular biology (Clifton, N.J.) · 2021Article
- Conserved biophysical features of the CaThe Journal of biological chemistry · 2020Article
Corrections and comments
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Authors and funding
8 authors at 2 institutions in 2 countries.
Funding
Abstract
Trichoplax adhaerens has only six cell types. The function as well as the structure of crystal cells, the least numerous cell type, presented an enigma. Crystal cells are arrayed around the perimeter of the animal and each contains a birefringent crystal. Crystal cells resemble lithocytes in other animals so we looked for evidence they are gravity sensors. Confocal microscopy showed that their cup-shaped nuclei are oriented toward the edge of the animal, and that the crystal shifts downward under the influence of gravity. Some animals spontaneously lack crystal cells and these animals behaved differently upon being tilted vertically than animals with a typical number of crystal cells. EM revealed crystal cell contacts with fiber cells and epithelial cells but these contacts lacked features of synapses. EM spectroscopic analyses showed that crystals consist of the aragonite form of calcium carbonate. We thus provide behavioral evidence that Trichoplax are able to sense gravity, and that crystal cells are likely to be their gravity receptors. Moreover, because placozoans are thought to have evolved during Ediacaran or Cryogenian eras associated with aragonite seas, and their crystals are made of aragonite, they may have acquired gravity sensors during this early era.
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