Basal body

Eukaryotic flagella. 1-axoneme, 2-cell membrane, 3-IFT (IntraFlagellar Transport), 4-Basal body, 5-Cross section of flagella, 6-Triplets of microtubules of basal body.

Longitudinal section through the flagella area in Chlamydomonas reinhardtii. In the cell apex is the basal body that is the anchoring site for a flagellum. Basal bodies originate from and have a substructure similar to that of centrioles, with nine peripheral microtubule triplets (see structure at bottom center of image).

A basal body (also called a basal granule or kinetosome) is an organelle formed from a centriole, and a short cylindrical array of microtubules. It is found at the base of a eukaryotic undulipodium (cilium or flagellum) and 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 within centrosomes, one type of microtubule organizing center (MTOC). These microtubules provide structure and facilitate movement of vesicles and organelles within many eukaryotic cells. Basal bodies, however, are specifically the bases for cilia and flagella that extend out of the cell.

Basal bodies are derived from centrioles through a largely mysterious process. They are structurally the same, each containing a microtubule triplet 9*3 helocoidal configuration forming a hollow cylinder.

Regulation of basal body production and spatial orientation is a function of the nucleotide-binding domain of γ-tubulin.

Flagellum(flagella) are basically attached to the cell membrane from a basal granule.

External links

• Histology at BU 21804loa - "Ultrastructure of the Cell: ciliated epithelium, cilia and basal bodies"