The mechanism of granulocyte nuclear shape determination: possible involvement of the centrosome.
Mature blood neutrophils (polymorphonuclear granulocytes) have characteristically complex nuclear shapes. The human neutrophil nucleus generally possesses 3-4 lobes; the mouse neutrophil nucleus frequently resembles a twisted toroid with a central hole. Myeloid tissue culture systems (e.g., human HL-60 and murine MPRO) can be induced to differentiate in vitro towards neutrophils by addition of retinoic acid, exhibiting the characteristic nuclear shape changes. Confocal immunostaining and thin-section transmission electron microscopic image data from differentiated HL-60 and MPRO cells clearly demonstrate proximity of the centrosomal region (containing dynein, gamma-tubulin and C-Nap1) to regions of granulocytic nuclear indentations. In addition, the centrosomal region, flanked by the Golgi apparatus, is shown to be present within the central hole of the toroidal mouse granulocyte nucleus. A role for the centrosomal region and associated microtubules in molding granulocytic nuclear shape is suggested.
Olins
Ada L
AL
Department of Biology, Bowdoin College, 6500 College Station, Brunswick, ME 04101, USA.
Olins
Donald E
DE
D000970:Antineoplastic Agents / Q000494:pharmacology; D002454:Cell Differentiation / Q000502:physiology; D002467:Cell Nucleus / Q000502:physiology*; D018385:Centrosome / Q000502:physiology*; D006098:Granulocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D014212:Tretinoin / Q000494:pharmacology
D000970:Antineoplastic Agents; D014212:Tretinoin