Amoeboid movement

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Amoeboid movement is a crawling-like type of movement accomplished by protrusion of cytoplasm of the cell involving the formation of pseudopodia. The cytoplasm slides and forms a pseudopodium in front to move the cell forward. This type of movement has been linked to changes in action potential; the exact mechanism is still unknown. This type of movement is observed in amoeboids, slime molds and some protozoans, as well as some cells in humans such as leukocytes. Sarcomas, or cancers arising from connective tissue cells, are particularly adept at amoeboid movement, thus leading to their high rate of metastasis.

While several hypotheses have been proposed to explain the mechanism of amoeboid movement, the exact mechanism is still unknown.[1]

Locomotion of amoeba occurs due the sol-gel conversion of the cytoplasm within its cell. The ectoplasm being called the plasma gel and the endoplasm the plasma sol. The conversion of the endoplasm to ecto and vice versa is called sol-gel conversion.[citation needed]

For example, when an amoeba moves, it extends the gelatinous cytosol pseudopium, which then results in the more fluid cytosol flowing after the gelatinous portion where it congeals at the end of the pseudopium. Inside the amoeba, there are proteins that can be activated to convert the gel into the more liquid state.

Dictyostelium cells and neutrophils can also swim, using a similar mechanism as for crawling.[2] [3]

References[edit]

  1. ^ R D Allen, and N S Allen. "Cytoplasmic Streaming in Amoeboid Movement" http://www.annualreviews.org/doi/abs/10.1146/annurev.bb.07.060178.002345 Allen, R. D.; Allen, N. S. (1978). "Cytoplasmic Streaming in Amoeboid Movement". Annual Review of Biophysics and Bioengineering 7: 469–495. doi:10.1146/annurev.bb.07.060178.002345. PMID 352246.  edit
  2. ^ Van Haastert, Peter J. M.; Hotchin, Neil A. (8 November 2011). "Amoeboid Cells Use Protrusions for Walking, Gliding and Swimming". In Hotchin, Neil A. PLoS ONE 6 (11): e27532. doi:10.1371/journal.pone.0027532. PMC 3212573. PMID 22096590. 
  3. ^ Bae, A. J.; Bodenschatz, E. (4 October 2010). "On the swimming of Dictyostelium amoebae". Proceedings of the National Academy of Sciences 107 (44): E165–E166. doi:10.1073/pnas.1011900107.