Centrin and tektin help to form the characteristic pattern of their walls, which in Drosophila embryos consist of doublets, rather than triplets, of microtubles.  
One study on clam oocytes speculated that one structure that contains them might have its own RNA genome.  The protein ninein (ny-NAY-in) and two of them make up a cell-cycle regulating structure.  Centrin and tektin help to form the characteristic pattern of their walls, which in Drosophila embryos consist of doublets, rather than triplets, of microtubles.  FTP, identify these structures whose astral fibers comprise the mitotic spindle, which in anaphase anchor chromosomes to either side of a cell.
One study on clam oocytes speculated that one structure that contains them might have its own RNA genome.  
centrioles