THE ORIENTATION OF PRIMARY CILIA DURING THE WOUND RESPONSE IN 3Y1 CELLS

The behavior of the primary cilia of 3Y1 cells in the interphase was i nvestigated by indirect immunofluorescence microscopy and transmission electron microscopy, using an antibody for tubulin. At 4.5 h after sc raping a part of a confluent cell sheet, the primary cilia of cells fa cing the wound were located predominantly forward of the nucleus on th e wounded side, and were oriented in the direction of the leading lame llae. Cytoplasmic microtubules (MTs), emanating from around the base o f the cilia, were well developed in the leading lamellae on the wounde d side. On the other hand, in the cells of an unperturbed area away fr om the wounded edge, the primary cilia remained randomly distributed n ear the nucleus. The position and a certain well-defined orientation o f a pair of centrioles seem to play an important role for the developm ent of cytoplasmic MTs, and consequently the orientation of the centri oles is controlled by the primary cilia.