Basal body
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
Assembly, structure
Cilia and basal bodies form during quiescence or the G1 phase of the cell cycle. Before the cell enters G1 phase, i.e. before the formation of the cilium, the mother centriole serves as a component of the centrosome.
In cells that are destined to have only one primary cilium, the mother centriole differentiates into the basal body upon entry into G1 or quiescence. Thus, the basal body in such a cell is derived from the centriole. The basal body differs from the mother centriole in at least 2 aspects. First, basal bodies have basal feet, which are anchored to cytoplasmic microtubules and are necessary for polarized alignment of the cilium. Second, basal bodies have pinwheel-shaped transition fibers that originate from the appendages of mother centriole.[5]
In multiciliated cells, however, in many cases basal bodies are not made from centrioles but are generated de novo from a special protein structure called the deuterosome.[6]
Function
During cell cycle dormancy, basal bodies organize primary cilia and reside at the cell cortex in proximity to plasma membrane. On cell cycle entry, cilia resorb and the basal body migrates to the nucleus where it functions to organize centrosomes. Centrioles, basal bodies, and cilia are important for mitosis, polarity, cell division, protein trafficking, signaling, motility and sensation.[7]
Mutations in proteins that localize to basal bodies are associated with several human ciliary diseases, including
Regulation of basal body production and spatial orientation is a function of the nucleotide-binding
Plants lack centrioles and only lower plants (such as mosses and ferns) with motile sperm have flagella and basal bodies.[17]
References
- ^ Engelmann, T. W. (1880). Zur Anatomie und Physiologie der Flimmerzellen. Pflugers Arch. 23, 505–535.
- PMID 20362083.
- PMID 21768326.
- ISBN 978-0-7637-3905-8. Retrieved 28 July 2019.
- PMID 23747070.
- PMID 24075808.
- PMID 19056680.
- S2CID 4310157.
- S2CID 2441702.
- S2CID 22088755.
- S2CID 12910768.
- PMID 11006213.
- PMID 15772089.
- S2CID 10676530.
- S2CID 16717895.
- PMID 16344310.
- ^ Philip E. Pack, Ph.D., Cliff's Notes: AP Biology 4th edition.
External links
- Histology image: 21804loa – Histology Learning System at Boston University - "Ultrastructure of the Cell: ciliated epithelium, cilia and basal bodies"