Introduction 2004a 2004 2005 2004b c 2004 2004 2007 Diversity of TNT-like structures 1 2006 2004 1 1 1 1 1 2 2 1 2 1 3 2007 2004 Fig. 1 a x y a 1 x z a b b 1 b 2 2004 a a 1 b b 1 b 2  Table 1 a Cell type  TNT-like structures  Cytoskeletal components  Membrane continuity/ “open-ended”  Cargo  2004 F-actin, myosin Va  b  Endosome-related organelles, lipid-anchored proteins (EGFP-f), EGFP-actin  2004 c  c  ND  Endosome-related organelles  2004 ND  ND  d  2005 ND  ND  Mitochondria, soluble proteins (GFP)  2005 F-actin, myosin Va  ND  ND  2005 ND  e  d  2005 F-actin  e  d  2005 ND  e  Calcium fluxes  2006 F-actin, microtubules  f  Mitochondria, endosome-related organelles, lysosomes  2006 F-actin  ND  Surfing Mycobacterium bovis bacillus Calmette-Guérin  2007 F-actin  b  MLV  2008 F-actin  b,e  HIV-1 protein Gag  a b c d e f ND: not determined Fig. 2 a a 1 a 2 2004 b b 1 b 2 b 2 b 1 2008 a b a 1 a 2 b 1 b 2  Fig. 3 a a 1 b b 1 c c 1 a c  2007 1 2005 2005 1 2008 3 2 1 2 1 2 1 3 2007 1 2006 2006 1 2004 Drosophila 1999 1999 3 2005 3 1 2002 2004 1 Formation of TNT-like structures 2004 Drosophila 1999 3 2007 2004 2004 2006 2008 2007 2004 2008 2004 2006 2008 2007 2004 1999 2008 2005 2 2 2008 1999 2005 TNT-like structures are conduits for the delivery of cargo 1 Cellular components 2004 2005 3 1 1 2004 2004 2005 4 2006 2006 Fig. 4 Emerging physiological implications of TNT-like structures  2004 2004 2004 1 2004 2005 2005 2007 4 1984 1994 2001 2001 2004 2005 2005 1 2004 2007 2005 1 2005 1 2005 4 Pathogens 3 4 2007 2008 1995 1996 2005 2006 2004 2007 2008 2008 3 1 2004 2004 2007 2008 1 2007 2007 2007 3 1 2006 1 Mechanism of transfer 3 2006 3 1 2004 2005 1 2004 2004 2008 3 1 2007 3 1 2004 2007 2008 Ultra-fine cellular extensions in tissue 2007 4 2003 2 Table 2 Selected examples of cell protrusions in tissue Protrusions  Tissue  Cytoskeletal components  Cargo  Length [μm]  Diameter [nm]  Growth speed [μm/min]  Thin, elongated, active filopodia and lamellipodia  1967 1995 a ND  a b a  Cytonemes  Drosophila 1999 F-actin  ND  <700  200  15  Cytoneme-like  1999 Drosophila 2000 b ND  b ND  b Apical peripodial extensions  Drosophila 2000 Microtubules  c  5–30  ND  ND  Myopodia  Drosophila 2000 2003 F-actin  ND  40  ND  ND  Myopodia-like  2002 Xenopus 1977 ND  ND  d ND  ND  Cellular extensions  Drosophila 2002 F-actin  Scabrous vesicles  40  ND  ND  Apical and lateral cell protrusion  Drosophila 2007 F-actin  c c 1–10  200  ND  a 1995 b 2000 c d 2002 ND: not determined 1967 1995 Drosophila 1999 2002 2007 2007 2000 2007 2007 Drosophila 2000 1992 2002 Drosophila 2000 2003 Xenopus 1977 2002 2002 2002 1981 2008 2