Centriole

In cell biology a centriole is a cylindrical organelle composed mainly of a protein called tubulin.

[7] The main function of centrioles is to produce cilia during interphase and the aster and the spindle during cell division.

An inability of cells to use centrioles to make functional flagella and cilia has been linked to a number of genetic and developmental diseases.

In particular, the inability of centrioles to properly migrate prior to ciliary assembly has recently been linked to Meckel–Gruber syndrome.

[26] Proper orientation of cilia via centriole positioning toward the posterior of embryonic node cells is critical for establishing left-right asymmetry, during mammalian development.

[citation needed] Some lineages of eukaryotes, such as land plants, do not have centrioles except in their motile male gametes.

Centrioles are completely absent from all cells of conifers and flowering plants, which do not have ciliate or flagellate gametes.

[31] Important genes such as those coding for centrins, required for centriole growth, are only found in eukaryotes, and not in bacteria or archaea.

The atypical distal centriole forms a dynamic basal complex (DBC) that, together with other structures in the sperm neck, facilitates a cascade of internal sliding that couples tail beating with head kinking.