Centrioles are barrel shaped organelles that play a central role in microtubule organization; in dividing cells, centrioles direct the formation of the mitotic spindle, and in differentiated cells, centrioles organize the formation of cilia and flagella. Centrioles typically exist in pairs, and to properly execute centriole-dependent processes, cells must possess one or two pairs of centrioles. Three properties of centrioles contribute to the strict copy number control: a precise duplication event that occurs once per cell cycle, equal partitioning of centriole pairs to daughter cells at division, and the long–term stability of centrioles once formed. While much is known about centriole duplication and segregation, relatively little is understood about the molecular basis of centriole stability. Five highly conserved factors required for centriole assembly have been identified in the nematode C. elegans. This includes SAS-6, a coiled-coil containing protein that forms a central scaffold for centriole assembly. Down regulation of any of the centriole assembly factors blocks formation of new centrioles but does not affect existing centrioles. We have recently identified a new mutant allele of the sas-6 gene that contains a missense mutation (D9V) affecting the globular N-terminal domain. This domain directs the formation of higher order oligomers of SAS-6 and the assembly of a centriole scaffold. Animals homozygous for this mutation exhibit an embryonic lethal phenotype marked by the presence of monopolar spindles, a phenotype consistent with a defect in centriole assembly. However, these mutants also exhibit an additional unexpected phenotype. In the male germ line of such mutants, centrioles duplicate normally during the early stages of spermatogenesis but appear to disassemble following the meiotic divisions. As a result, sperm lack detectable levels of centriole proteins including SAS-6, SAS-4 and SPD-2. Thus in the male germ line, centrioles appear to duplicate normally but the long-term stability of these structures is compromised. Our results thus indicate that SAS-6 does not just serve as a scaffold for centriole assembly but also plays a key role in maintaining the structural integrity of these organelles. Future studies will be directed toward identifying how this mutant version of SAS-6 affects the critical protein-protein contacts that underlie centriole longevity.