Cytoneme

filopodium - a thin, tubular extension of a cell’s plasma membrane that has a core composed of tightly bundled, parallel actin filaments. Filopodia can extend more than 100 μm and have been measured as thin as 0.1 μm and as thick as 0.5 μm. Cytonemes with a diameter of approximately 0.2 μm and as long as 80 μm have been observed in the Drosophila wing imaginal disc.^[1]

tunneling nanotubes^[24] and dendrites. The term cytoneme was coined to denote the presence of cytoplasm in their interior (cyto-) and their finger-like appearance (-neme), and to distinguish their role as signaling, rather than structural or force-generating, organelles.^{[citation needed}

neutrophils.^[39] Recent observations suggest that cytonemes have also an important role during vertebrate development. Recent observations suggest that cytonemes also have an important role during development of the zebrafish neural plate^[40] where they transport Wnt8a and of the chick limb where they transport Sonic hedgehog.^[41]