Collocyte

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Collocyte is a term variously applied in botany [1] and zoology [2] [3] [4] to cells that produce gluey substances, or that bind or capture prey or assorted objects by securing them with gluey materials and structures, or that simply look smooth and gelatinous. Literally the word means "glue cell", and it has a number of poorly distinguished synonyms, such as colloblast. [5]

Contents

Use in botany

In English the term "collocyte" (or, less formally, "glue cell") is uncommon in botanical publications. It appears more often in French texts; however, it sometimes is used in referring to individual cells in ground tissues of types characterised as collenchyma. [1]

Use in zoology

In zoology the word "collocyte" applies to several different types of cell in very different taxa, and there are a few similar terms used confusingly or interchangeably, such as colloblast. [5] Some of the terms refer to specialised subject matter, so from time to time variations and inconsistent definitions have been coined independently in niche disciplines. For example, glial cells sometimes are called "glue cells" but have little in common with other types of so-called glue cells. [6]

Apart from such difficulties, "glue cells" of various types commonly occur in taxa of animals that are practically unrelated to each other, and in such cases they are as a rule non-homologous and differ profoundly in their morphology, histology and function. This suggests that distinct terms should be allocated to the different types. The problem is so marked that to avoid confusion many workers are abandoning traditional terms in favour of new words. [7]

Collocytes in Tunicata

Among the taxa of animals that have some form of cells that might be classed as collocytes, are the larvae of sessile forms of Tunicates. Near the head end, most of those have collocytes with which they permanently fasten themselves to the substrate.

Collocytes in Ctenophora

Perhaps the most striking and celebrated examples of collocytes are those of the Ctenophora (comb jellies). The Ctenophora use their colloblasts or collocytes in hunting and gathering food, in much the same way as members of the Cnidaria use cnidocytes; they keep the cells in a retracted form until they deploy them for securing prey. In keeping with their food capturing function, the collocytes sometimes are called "lasso cells", but as is to be expected of common names, the term is not precise and is variously applied to both colloblasts and cnidocytes. The retracted mechanism is kept coiled in the Ctenophora, as opposed to inside out in the Cnidaria. The Cnidaria evert their stings to penetrate the prey, but the Ctenophora eject microscopic balls of adhesive mucus that stick to the prey externally, trailing threads that as a rule do not lose attachment to the parent colloblast. The structure of these specialized cells is extremely complex and varies among ctenophore species. Their mechanisms are still under study. [8]

Collenocytes

In some organisms collocytes that attach the animal to substrates must be able to release their grip as well as establish it. Commonly, though not always, this requires the ability to dissolve the adhesive substances after the adhesion has been achieved. When a glandular structure has the ability to perform both the adhesion and the dissolving of the adhesive, it is called a duo-gland [8] This is a very common requirement and examples occur in Platyhelminths, both parasitic [9] and free-living, [10] Annelida, [11] Echinodermata [12] and other phyla. In some organisms the adhesion it affords is so remarkably reversible that it is used as the basis of locomotion over solid surfaces. [10]

Confusion between collocytes and collencytes

Another class of apparently similarly named cells, "collencytes" occurs in sponges, but in this case there is little to do with adhesion. The term was derived from the tissue in which the cells occur: collenchyma. [13] The name collenchyma in turn was borrowed from botany because of a fancied, essentially irrelevant, resemblance between sponge tissue and a particular class of ground tissue in plants. The collencytes are one of the classes of component cells of the sponges' tissue, loose mesenchyme between the ectoderm and the endoderm in the body wall. [14] The functions of the collencytes are not yet fully understood; they are branched amoeboid cells and appear to produce collagen and play roles in forming sponge spicules. It even has been proposed that they have primitive nerve-like physiologic roles. [15]

Related Research Articles

<span class="mw-page-title-main">Cnidaria</span> Aquatic animal phylum having cnydocytes

Cnidaria is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter.

<i>Hydra</i> (genus) Genus of cnidarians

Hydra is a genus of small freshwater organisms of the phylum Cnidaria and class Hydrozoa. They are native to the temperate and tropical regions. The genus was named by Linnaeus in 1758 after the Hydra, which was the many-headed beast defeated by Heracles, as when the animal had a part severed, it would regenerate much like the hydra’s heads. Biologists are especially interested in Hydra because of their regenerative ability; they do not appear to die of old age, or to age at all.

<span class="mw-page-title-main">Invertebrate</span> Animals without a vertebral column

Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column, derived from the notochord. This is a grouping including all animals apart from the chordate subphylum Vertebrata. Familiar examples of invertebrates include arthropods, mollusks, annelids, echinoderms and cnidarians.

<span class="mw-page-title-main">Placozoa</span> Basal form of free-living invertebrate

Placozoa is a phylum of the simple animals that are marine and free-living (non-parasitic). Placozoans are simply blob-like animals without any body part or organ, and are merely aggregates of cells. Moving in water by ciliary motion, eating food by engulfment, reproducing by fission or budding, they are described as "the simplest animals on Earth." Structural and molecular analyses have supported them as among the most basal animals, thus, constituting the most primitive metazoan phylum.

<span class="mw-page-title-main">Sponge</span> Animals of the phylum Porifera

Sponges, the members of the phylum Porifera, are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.

<span class="mw-page-title-main">Cnidocyte</span> Explosive cell containing one giant secretory organelle (cnida)

A cnidocyte is an explosive cell containing one large secretory organelle called a cnidocyst that can deliver a sting to other organisms. The presence of this cell defines the phylum Cnidaria. Cnidae are used to capture prey and as a defense against predators. A cnidocyte fires a structure that contains a toxin within the cnidocyst; this is responsible for the stings delivered by a cnidarian.

<span class="mw-page-title-main">Ctenophora</span> Phylum of gelatinous marine animals

Ctenophora comprise a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming, and they are the largest animals to swim with the help of cilia.

<i>Aurelia aurita</i> Species of jellyfish

Aurelia aurita is a species of the genus Aurelia. All species in the genus are very similar, and it is difficult to identify Aurelia medusae without genetic sampling; most of what follows applies equally to all species of the genus.

<span class="mw-page-title-main">Nerve net</span>

A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a condensation of neurons or, in more advanced forms, a central nervous system, organisms with radial symmetry are associated with nerve nets, and are found in members of the Ctenophora, Cnidaria, and Echinodermata phyla, all of which are found in marine environments. In the Xenacoelomorpha, a phylum of bilaterally symmetrical animals, members of the subphylum Xenoturbellida also possess a nerve net. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net.

<span class="mw-page-title-main">Tentacle</span> Varied organ found in many animals and used for palpation and manipulation

In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainly like muscular hydrostats. Most forms of tentacles are used for grasping and feeding. Many are sensory organs, variously receptive to touch, vision, or to the smell or taste of particular foods or threats. Examples of such tentacles are the eyestalks of various kinds of snails. Some kinds of tentacles have both sensory and manipulatory functions.

<span class="mw-page-title-main">Ascidiacea</span> Group of non-vertebrate marine filter feeders comprising sea squirts

Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of a polysaccharide.

<span class="mw-page-title-main">Coelenterata</span> Term encompassing animal phyla Cnidaria and Ctenophora

Coelenterata is a term encompassing the animal phyla Cnidaria and Ctenophora. The name comes from Ancient Greek κοῖλος (koîlos) 'hollow', and ἔντερον (énteron) 'intestine', referring to the hollow body cavity common to these two phyla. They have very simple tissue organization, with only two layers of cells, and radial symmetry. Some examples are corals, which are typically colonial, and hydrae, jellyfish, and sea anemones, which are solitary. Coelenterata lack a specialized circulatory system relying instead on diffusion across the tissue layers.

Colloblasts are unique, multicellular structures found in ctenophores. They are widespread in the tentacles of these animals and are used to capture prey. Colloblasts consist of a collocyte containing a coiled spiral filament, internal granules and other organelles.

Mesoglea refers to the extracellular matrix found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton. It is related to but distinct from mesohyl, which generally refers to extracellular material found in sponges.

<span class="mw-page-title-main">Mesenchyme</span> Type of animal embryonic connective tissue

Mesenchyme is a type of loosely organized animal embryonic connective tissue of undifferentiated cells that give rise to most tissues, such as skin, blood or bone. The interactions between mesenchyme and epithelium help to form nearly every organ in the developing embryo.

Bioadhesives are natural polymeric materials that act as adhesives. The term is sometimes used more loosely to describe a glue formed synthetically from biological monomers such as sugars, or to mean a synthetic material designed to adhere to biological tissue.

<span class="mw-page-title-main">Cydippida</span> Order of comb jellies with retractable branched tentacles

Cydippida is an order of comb jellies. They are distinguished from other comb jellies by their spherical or oval bodies, and the fact their tentacles are branched, and can be retracted into pouches on either side of the pharynx. The order is not monophyletic, that is, more than one common ancestor is believed to exist.

<span class="mw-page-title-main">Snail slime</span> External bodily secretion produced by snails

Snail slime (mucopolysaccharide) is a kind of mucus produced by snails, which are gastropod mollusks. Land snails and slugs both produce mucus, as does every other kind of gastropod, from marine, freshwater, and terrestrial habitats. The reproductive system of gastropods also produces mucus internally from special glands.

<span class="mw-page-title-main">Arthropod adhesion</span>

Arthropods, including insects and spiders, make use of smooth adhesive pads as well as hairy pads for climbing and locomotion along non-horizontal surfaces. Both types of pads in insects make use of liquid secretions and are considered 'wet'. Dry adhesive mechanisms primarily rely on Van der Waals' forces and are also used by organisms other than insects. The fluid provides capillary and viscous adhesion and appears to be present in all insect adhesive pads. Little is known about the chemical properties of the adhesive fluids and the ultrastructure of the fluid-producing cells is currently not extensively studied. Additionally, both hairy and smooth types of adhesion have evolved separately numerous times in insects. Few comparative studies between the two types of adhesion mechanisms have been done and there is a lack of information regarding the forces that can be supported by these systems in insects. Additionally, tree frogs and some mammals such as the arboreal possum and bats also make use of smooth adhesive pads. The use of adhesive pads for locomotion across non-horizontal surfaces is a trait that evolved separately in different species, making it an example of convergent evolution. The power of adhesion allows these organisms to be able to climb on almost any substance.

Rhabditophora is a class of flatworms. It includes all parasitic flatworms and most free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of the species in the phylum Platyhelminthes, excluding only the catenulids, to which they appear to be the sister group.

References

  1. 1 2 Buvat, Roger (1989). Ontogeny, cell differentiation, and structure of vascular plants. Berlin New York: Springer-Verlag. ISBN   9780387192130.
  2. ↑ Cloney, Richard A.; Larval adhesive organs and metamorphosis in ascidians; Cell and Tissue Research, Volume 183, Number 4, 423-444, DOI: 10.1007/BF00225658; 1977
  3. ↑ Cloney, Richard A.; Larval adhesive organs and metamorphosis in ascidians II. The mechanism of eversion of the papillae of Distaplia occidentalis; Cell and Tissue Research, Volume 200, Number 3, 453-473, DOI: 10.1007/BF00234856; 1979
  4. ↑ Eeckhaut, I. et al. Functional morphology of the tentacles and tentilla of Coeloplana bannworthi (Ctenophora, Platyctenida), an ectosymbiont of Diadema setosum (Echinodermata, Echinoida); Zoomorphology Volume 117, Number 3, 165-174, DOI: 10.1007/s004350050041; 1997
  5. 1 2 Harmer, Sir Sidney Frederic; Shipley, Arthur Everett et alia: The Cambridge natural history Volume 1, Protozoa, Porifera, Coelenterata, Ctenophora, Echinodermata. Macmillan Company 1906
  6. ↑ J. Edward Bruni; Donald G. Montemurro (2009). Human Neuroanatomy: A Text, Brain Atlas, and Laboratory Dissection Guide. Oxford University Press. pp. 1–. ISBN   978-0-19-537142-0.
  7. ↑ Simpson, Tracy (1984). The cell biology of sponges. New York: Springer-Verlag. ISBN   9780387908939.
  8. 1 2 von Byern, Janek; Grunwald, Ingo (2010). Biological adhesive systems : from nature to technical and medical application. Wien u.a: Springer. ISBN   9783709101414.
  9. ↑ Whittington ID, Cribb BW. Adhesive secretions in the Platyhelminthes. Adv Parasitol. 2001;48:101-224
  10. 1 2 Lengerer B, Pjeta R, Wunderer J, Rodrigues M, Arbore R, Schärer L, Berezikov E, Hess MW, Pfaller K, Egger B, Obwegeser S, Salvenmoser W, Ladurner P. Biological adhesion of the flatworm Macrostomum lignano relies on a duo-gland system and is mediated by a cell type-specific intermediate filament protein. Front Zool. 2014 Feb 12;11(1):12. doi: 10.1186/1742-9994-11-12.
  11. ↑ Martin, Gary G. The duo-gland adhesive system of the archiannelids Protodrilus and Saccocirrus and the turbellarian Monocelis. Zoomorphology 01/1978; 91(1):63-75. DOI:10.1007/BF00994154
  12. ↑ Jangoux, Michel. Echinoderm studies 5 (1996) Publisher: CRC Press 1996. ISBN   978-9054106395
  13. ↑ CHENG, THOMAS C.; YEE, HERBERT W. F.; RIFKIN, ERIK. Studies on the Internal Defense Mechanisms of Sponges. PACIFIC SCIENCE, Vol. XXII, July 1968
  14. ↑ Lankester, E. Ray. A treatise on zoology. Volume 2. London, A. and C. Black 1900
  15. ↑ LI Hui, ZHANG Xiao-Yun, WANG An-Tai. Exploration on primordial nervous substances in sponges. Current Zoology(formerly Acta Zoologica Sinica), Dec. 2005, 51(6):1091 - 1101
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