Reticulopodia
From Foraminifera
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Contents |
Definition
Reticulopodia, also known as reticulose pseudopodia, net-like pseudopods which form complex irregular anastomosing networks.
"Reticulopodia have been variously termed 'granuloreticulopodia', 'pseudopodial networks', 'rhizopodia, and "cytoplasmic strands." (from Bowser & Travis, 2002)
"The most remarkable feature of the granular rhizopodia of foraminifera is the typical bidirectional cytoplasmic flow ... Granules are transported in both directions simultaneously even in extremely fine rhizopodial strands" (from Lipps,1993)
Function
"Rhizopodia are crucial in obtaining the energy necessary for the successful completion of the Radiolarian (and foraminiferal) life cycle. Additionally, the rhizopodia act to increase the surface area of the cell, improving the rates of release of metabolic wastes and the uptake of oxygen. The separation of the cytoplasm is thought to allow for increased control of the diffusion of large molecules within the cell, such as fat globules, and organelles." (from [1])
Mechanical role
- locomotion (see reticulopodia in action)
- anchoring and/or stabilazing in/on sediment or on other substrata
- capture of food or grain particles
- transport of organelles, daughter cells, proteins, mineral grains, food particles etc.
Sensory role
- food search
- danger (stress signals) monitoring
- transfer of signals/information (probably via signal proteins)
Morphogenetic role
- shaping shell/chamber morphology
Primary and derived reticulopodial features
(from Bowser & Travis, 2002 - p. 446, table 1)
"Primary features:
- branching and anastomosing pseudopodial pattern; contain cytoplasmic granules
- presence of MOVs (motility organizing vesicles)
- rapid, bidirectional transport of both granules and surface-attached particles
- extremely dynamic microtubule cytoskeleton, displaying axial (sliding) and lateral (bending) movements
- unique tubulin assembly/disassembly kinetics and storage polymorphs
Derived features:
- pseudopodial branching patterns and motile behaviors
- organelle complement (e.g., contractile vacuoles in Reticulomyxa)
- 3D patterning of microtubules (e.g., coiling in Astrammina rara)
- distribution of actin microfilaments
- surface elaborations, such as secreted adhesive matrices"
Breuker, Ralf N. (1997): Cytoskelettkomponenten des plasmodialen Rhizopoden Reticulomyxa filosa. PhD Theses - Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften der Abteilung für Biologie an der Ruhr-Universität Bochum
