The centriolar antigen expression in TC7 cells is dependent on growth conditions and occurs at a particular time point in G1

Immuno-electron-microscopic localization of a centriole-related antigen in ciliated cells

An antigen common to purported centriolar and basal body regions of a variety of cell types was previously visualized by immuno-fluorescence microscopy. The present study demonstrates the localization of the antigen relative to the defined basal body structures of ciliated tracheal cells at the electron-microscopic level. After ethyldimethylaminopropyl carbodiimide-glutaraldehyde-saponin (EGS) fixation and permeabilization, immunoferritin labeling is consistently found associated with amorphous electron-opaque material in proximity to basal bodies and their ciliary rootlets, but not with basal body microtubules themselves. This distribution pattern is distinct from that of other proteins found in the apical region of ciliated cells, such as calmodulin. It is proposed that the dense material may be analogous to pericentriolar material of centrosomes.

Centrosomes and mitotic poles

The original theory of the centrosome as the 'reproductive organ' of the cell provides a logical explanation of the mitotic poles and the accuracy of cell division. No alternative explanation has replaced it. The historical problem was the failure to identify centrosomes as compact physical bodies in a great many kinds of cells. In this essay, I consider the evidence that centrosomes are flexible bodies; they may take on alternative forms and their forms determine the shapes of mitotic poles and other organizers of microtubular structures. Compact corpuscular centrosomes are not necessary and would not be expected in cases where microtubules clearly do not originate from point sources. A model of the flexible centrosome is introduced and the speculation that the centrosome is a bearer of morphological information is considered.