Page "Centrosome" Paragraph 13

The evolutionary history of the centrosome and the centriole has been traced for some of the signature genes, e. g. the centrins.

Centrins participate in calcium signaling and are required for centriole duplication.

There exist two main subfamilies of centrins, both of which are present in the early-branching eukaryote Giardia intestinalis.

Centrins have therefore been present in the common ancestor of eukaryotes.

Conversely, they have no recognizable homologs in archea and bacteria and are thus part of the " eukaryotic signature genes.

" Although there are studies on the evolution of the centrins and centrioles, no studies have been published on the evolution of the pericentriolar material.