Ameboide

Ameboide, or amoeboid, describes a form of cell shape and locomotion characterized by the extension of temporary cytoplasmic projections called pseudopodia. Ameboid movement allows cells to crawl across surfaces and to surround and ingest particles through phagocytosis. Movement is driven by dynamic rearrangements of the actin cytoskeleton at the leading edge, coordinated cytoplasmic flow, and changes in cell shape that create local protrusions and retractions. Variations include lobopodial amoeboid motion, which uses broad, blunt pseudopodia, and more slender, filopodial forms.

In biology, amoeboid movement is seen in diverse contexts. Free-living protists such as those in the Amoebozoa group (for example, Amoeba proteus) exhibit classic amoeboid motility. In multicellular organisms, certain immune cells, notably macrophages and neutrophils, use amoeboid movement to migrate to sites of infection or injury. Amoeboid locomotion also facilitates cellular remodeling during development and tissue repair.

Amoeboid movement is a major subject of study in cell biology and biophysics because it provides a model for understanding basic mechanisms of motility, shape change, and force generation. In cancer biology, some tumor cells can switch to amoeboid migration in confined or protease-poor environments, a transition known as amoeboid or mesenchymal-amoeboid transition, which has implications for invasion and metastasis. Model organisms such as Dictyostelium discoideum have been instrumental in elucidating the principles underlying amoeboid behavior.