A short cylindrical organelle found in
eukaryotic cells, except those of higher
plants. Each centriole is composed of cylinders of nine triplet microtubules
in a ring. Centrioles occur in pairs arranged at right angles to each other
at the center of a microtubule organizing center (MTOC) or centrosome.
|A high magnification electron micrograph showing
a centriole in transverse section. Its wall is made up of 9 sets of
triplets. Each triplet is composed of 3 subunits: a, b, and c, which
form a microtubule
A centriole is similar in structure to the basal body found at the base
of eukaryotic cilia and flagella
and organizes the axoneme, the bundle of microtubules and other proteins
forming the core of each cilium or flagellum.