PSEUDOPOD

'Pseudopods' or 'pseudopodia' (false feet) are temporary projections of eukaryotic cells. Cells having this faculty are generally referred to as amoeboids.

Contents

Formation

Function

Mechanical role

Sensory role

Morphology

Other meanings of the word (The Abyss)

Formation

First, the cell surface extends a membrane process, termed a 'lamellipodium'. Polymerization of actin takes place and form filaments at the leading edge, which subsequently will blend into one another to form networks. It is supposed that actin polymerization is at the origin of the force propelling the cell forwards.

Function

Mechanical role

Pseudopods are one of the three locomotion modes of unicellular organisms (together with flagella and cilia).

Sensory role

Pseudopods also capture prey by phagocytosis. Phagocytotic pseudopods have arisen in a number of different protist groups, but also in some cells (phagocytes) in multicellular organisms.

Morphology

Pseudopods can be classified into several varieties according to their appearance:

★ 'Lobopodia' are bulbous, short and blunt in form, very typical of Amoebozoa.

★ 'Fillopodia' are more slender and filiform with pointed ends, consisting mainly of ectoplasm. These formations are supported by microfilaments.

★ 'Reticulopodia', also known as 'reticulose pseudopods', are complex formations where individual pseudopods are blended together and form irregular nets.

★ 'Axopodia' are thin pseudopods containing complex arrays of microtubules and are enveloped by cytoplasm. Axopodia are responsible for phagocytosis, by rapidly retracting in response to physical contacts. They are observed in radiolaria and heliozoa.

Other meanings of the word (The Abyss)

In the film The Abyss, a creature called a pseudopod was acclaimed as one of the first successful uses of CGI in film.