amoeboidly

Amoeboidly is an English adverb used to describe movement or behavior in an amoeboid manner. It denotes locomotion characterized by the formation and retraction of pseudopodia, with cytoplasmic flow that propels the cell forward, as seen in many amoebae and in cells that move in an amoeboid fashion.

In cells, amoeboid movement arises from dynamic rearrangements of the actin cytoskeleton near the cell cortex. Pseudopods extend as actin polymerizes at the leading edge; the rear contracts, and cytoplasm streams toward the extending projection. Migration can proceed via lobopodial (bulky) pseudopods or more slender bleb- or filopodia-based protrusions, and may rely on hydrostatic pressure changes. In vertebrate tissues, immune cells such as neutrophils and macrophages often move amoeboidly to traverse extracellular space, especially in 3D matrices where low adhesion suffices.

Amoeboid movement is contrasted with mesenchymal migration, which depends on elongated cell shapes and strong adhesions. The term is used in cell biology, microbiology, and immunology to describe behavior rather than a taxonomic classification. Organisms that display amoeboid locomotion include true amoebae (e.g., Amoeba species) and social amoebae (Dictyostelium discoideum); some parasites (Entamoeba histolytica) and cancer cells can also exhibit amoeboid movement during invasion.

Etymology: The adverb is formed from amoeboid, itself from amoeba + -oid, with the adverbial suffix -ly.