title: Surface transport properties of reticulopodia: do intracellular and extracellular motility share a common mechanism?
abstract: The reticulopodial networks of the foraminiferan protozoans Allogromia sp., strain NF, and A. laticollaris display rapid (up to 11 microns/second) and bidirectional saltatory transport of membrane surface markers (polystyrene microspheres). Electron microscopy shows that microspheres adhere directly to the reticulopodial surface glycocalyx. A videomicroscopic analysis of this phenomenon reveals that microsphere movement is typically independent of pseudopod extension/withdrawal and that particles of different sizes and surface properties display similar motile characteristics. The motile properties of surface-associated microspheres appear identical to those of saltating intracellular organelles. Indeed, in some instances the surface-attached microspheres appear transiently linked in motion to these underlying organelles. Our observations suggest that, in reticulopodia, surface transport of microspheres and intracellular transport of organelles are driven by a common mechanism.
mesh_terms: D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000502:physiology*; D002465:Cell Movement; D003593:Cytoplasm / Q000502:physiology; D056890:Eukaryota / Q000502:physiology*; D005110:Extracellular Space / Q000502:physiology; D008560:Membrane Fluidity