The implications of centrosomal RNA

The existence of nucleic acids associated with the centrosome has been controversial for many years. Founded in the 1950s and the subject of active inquiry in the 1970s and 1980s, the topic entered a period of hiatus for over a decade that was essentially capped by a comprehensive and authoritative review in 2000. The consensus at the time was that there was no evidence supporting the presence of DNA in the centrosome and related structures, although the existence of centrosomal RNA remained a possibility. The question of centrosomal DNA remains unresolved. To this day the evidence-with no recent additions-is inconclusive and sometimes contradictory. The existence of RNA at the centrosome, however, has been conclusively demonstrated. Consequently, we may now revisit the lines of inquiry established decades ago and ask, what are the functions and origins of centrosome-associated RNA (cnRNA)? Is it important for replication of the mitotic center? Does it play a role in spindle assembly? Does it represent the remnant of a once-independent genome, derived by symbiogenesis? The questions are fundamental, interdependent and now answerable.