A
basal body (synonymous with
basal granule,
kinetosome, and in older cytological literature with
blepharoplast) is a protein structure found at the base of a
eukaryotic undulipodium (
cilium or
flagellum). It is formed from a
centriole and several additional protein structures, and is, essentially, a modified centriole. Basal body serves as a nucleation site for the growth of the
axoneme microtubules. Centrioles, from which basal bodies are derived, act as anchoring sites for proteins that in turn anchor microtubules, and are known as the
microtubule organizing center (MTOC). These microtubules provide structure and facilitate movement of vesicles and organelles within many eukaryotic cells.