World Library  
Flag as Inappropriate
Email this Article

Collodictyon

Article Id: WHEBN0035632441
Reproduction Date:

Title: Collodictyon  
Author: World Heritage Encyclopedia
Language: English
Subject: Eukaryote, Eukaryotes, Ochrophyta, Pompholyxophrys, Holomycota
Collection: Eukaryotes, Origin of Life, Protist Genera
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Collodictyon

Collodictyon is a basal genus of single-celled eukaryotes not closely related to any heretofore known kingdom of that domain.[1]

Contents

  • Taxonomy and phylogeny 1
  • Description 2
  • Distribution 3
  • Feeding 4
  • History 5
  • Press releases 6
  • References 7
  • See also 8

Taxonomy and phylogeny

Eukaryotes
Unikonta
Amoebozoa Amoeba


metazoa (Animals) Humans


Fungi




"bikonta"


plants


red algae



Paramecium



Collodictyon



Phylogenetic position of Collodictyon relative to a few example organisms[2]

Three species are currently recognised in this genus. The type species is Collodictyon triciliatum. A second species—Collodictyon sparsevacuolatum—named by Skuja is also recognised; this species is found in freshwater in the United States and Europe. A third species Collodictyon sphaericum has been described but its description is in doubt. A fourth species—Collodictyon hongkongense—has been described by Skvortzow but this description is considered inadequate and this species is regarded as being of dubious validity.[3]

Along with the genus

  • Collodictyon triciliatum at 400x in phase contrast by microuruguay 25 June 2011 Video on YouTube

See also

  1. ^ a b c d e f Agence France-Presse (AFP) (26 April 2012). "Scientists find 'man's remotest relative' in lake sludge". France 24 International News. Retrieved 2012-04-25. 
  2. ^ a b c d Zhao, Sen; Fabien Burki, Jon Bråte, Patrick Keeling,  
  3. ^ a b MD Guiry in Guiry MD & Guiry GM 2012. "Collodictyon HJ Carter, 1865: 289". AlgaeBase. World-wide electronic publication. Galway: National University of Ireland. Retrieved 28 April 2012. 
  4. ^ Live Science Strange, Organism Has Unique Roots in the Tree of Life, by Jennifer Welsh, 29 April 2012
  5. ^ a b Brugerolle, Guy; Bricheux G; Philippe H; Coffea G (March 2002). "Collodictyon triciliatum and Diphylleia rotans (=Aulacomonas submarina) form a new family of flagellates (Collodictyonidae) with tubular mitochondrial cristae that is phylogenetically distant from other flagellate groups". Protist 153 (1): 59–70.  
  6. ^ Rhodes, Robert Clinton (29 October 1917). Binary Fission in Collodictyon tricilliatum. Berkeley, California: University of California. number of flagella is four (page 238 of original book; page 50 of the pdf file). Flagella are equal in length, as long as the body or possibly longer... 
  7. ^ a b Carter, H.J. (1865). "XXXII.—On the fresh- and salt-water Rhizopoda of England and India". Journal of Natural History Series 3. 3 15 (88): 277–293.  
  8. ^ a b c Rhodes, Robert Clinton (29 October 1917). Binary Fission in Collodictyon tricilliatum. Berkeley, California: University of California. 
  9. ^ Cambra Sánchez, J.; Álvarez Cobelas, M. & Aboal Sanjurjo, M (1988). "Lista florística y bibliográfica de los clorófitos (Chlorophyta) de la Península Ibérica, Islas Baleares e Islas Canarias". Asociación Española de Limnología. p. 9. Retrieved 28 April 2012. 
  10. ^ Lackey, James B. (1942-01-01). "The Plankton Algae and Protozoa of Two Tennessee Rivers". American Midland Naturalist 27 (1): 191–202.  
  11. ^ a b Rhodes, Robert Clinton (29 October 1917). Binary Fission in Collodictyon tricilliatum. Berkeley, California: University of California. (page 220 from original book; page 32 from the pdf) ... In its feeding habits, Collodictyon is most interesting. When hungry, it can be distinguished from moribund stages in which all food is extruded by pseudopial projections from the lateral groove or sulcal region ... these pseudopodia ... function actively whenever the organism is seeking food. At these times when coming in contact with Protozoa or algae which it may use for food, they are wafted to the sulcal region by the flagella, or else Collodictyon aligns itself alongside of its prey with the pseudopodia in contact. ... Both the flagella and the pseudopodia appear sensitive to food stimulus ... 
  12. ^ Rhodes, Robert Clinton (29 October 1917). Binary Fission in Collodictyon tricilliatum. Berkeley, California: University of California. (page 239 of original book; page 51 of pdf file) ... Collodictyon is "one of the simplest and most primitive of the Polymastigina"... 
  13. ^ Yngve Vogt (23 April 2012). "Mankind's remotest relative". Apollon.  Original Norwegian press release with pictures of researchers.
  14. ^ "Scientists find 'man's remotest relative' in lake sludge". 26 April 2012. 

References

[14] Scientists from [1] may yield insights into the prehistoric beginnings of life hundreds of millions of years ago.Collodictyon Scientists speculate that further study of

Press releases

In 1917, it was classified as being one of the "simplest and most primitive" type of Polymastigina.[12]

Pyriform, straight, or slightly bent upon itself, bifid (two-lobed) at the small extremity, presenting at the larger one an indentation, from which spring three cilia. Structure transparent, cancellated, composed of globular cells, with a strongly marked, greenish granule here and there in the triangular spaces between them. Locomotive, swimming by means of the cilia; subpolymorphic, flexible, yielding, capable of assuming a globular form ... or one more or less modified by the body it may incept . . . ; enclosing crude material for nourishment in stomachal spaces, and ejecting the refuse, like Amoeba. Provided with a nucleus and contracting vesicles.
—Carter, 1865[8]

Collodictyon triciliatum was originally named by H. J. Carter in 1865.[7] Carter's original species description is as follows:

History

Dag Klaveness reported that the creatures are "not sociable" and will cannibalize each other when food is scarce.[1] Collodictyon will ingest freshwater algae and appears to be unable to survive on a diet of bacteria alone. Curiously the algae remain viable at least for a while after being engulfed. It is possible that the algae are "enslaved".[11]

In its feeding habits, Collodictyon is most interesting. When hungry, it can be distinguished from moribund stages in which all food is extruded by pseudopial projections from the lateral groove or sulcal region ... these pseudopodia ... function actively whenever the organism is seeking food. At these times when coming in contact with Protozoa or algae which it may use for food, they are wafted to the sulcal region by the flagella, or else Collodictyon aligns itself alongside of its prey with the pseudopodia in contact. ... Both the flagella and the pseudopodia appear sensitive to food stimulus ...
—Robert Clinton Rhodes, 1917[11]

The feeding habits of this organism have rarely been studied.

Diagram of Collodictyon failed ingestion of a Pandorina. The Pandorina escapes and the Collodictyon dies from water loss. Sketched by researcher Robert Clinton Rhodes; sketch appeared in print in 1917.

Feeding

Originally Collodictyon triciliatum was described from the island of Bombay and later in central Europe.[7][8] In Europe this species is found from Spain[9] to Norway.[2] Collodictyon has also been reported in North America.[3][8][10]

Distribution

Collodictyon triciliatum has four flagella connected to basal bodies, generally of equal length, as long as or slightly longer than the body of Collodictyon.[6] Number one flagellum is connected to a dorsal root, while number two flagellum is connected to a ventral root. Number three and four flagella are on either side of these two and have dorsal roots.

Members of this genus are known to reproduce asexually through cell division. Whether sexual reproduction occurs is currently unknown.

dictyosomes are present and arranged in a horseshoe like shape.[5]

The mitochondria have tubular cristae.

The nucleus typically lies in the posterior half of the cell.

The cell shape is variable but is mostly obovoid to ellipsoid. The lateral cell margins maybe somewhat angular leading to a broad, truncated rounded apex. This posterior margin narrows posteriorly and either bears 1-3 lobes or is simply broadly rounded. This margin is often pseudopodial.

The species in this genus range in size from 30 to 50 µm in length,[1] can grow broad pseudopodia, and have four flagella[1] and a ventral feeding groove or sulcus.[2] They are devoid of cellulosic cell walls, chloroplasts or stigmata. There are two to several contractile vacuoles.

Sketch of Collodictyon looking from the rear, with four flagella.

Description

Another genus that is related to Collodictyon is Sulcomonas.

Brugerolle has proposed a family, Collodictyonidae for this genus and Diphylleia.[5]

and in need of resolution (reorganisation into different groups). For this reason inclusion of this genus within the excavates may not assist in understanding its phylogenetic position. polyphyletic is considered to be clade. However this latter Excavata They share some morphological features with the species currently placed within the [4][2]

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.