The centrosome and spindle as a ribonucleoprotein complex.

The notion of nucleic acids in the spindle, and particularly, the centrosome has a long history of inquiry, doubt, and debate. However, the association of specific RNAs with these structures is now confirmed by several investigators. What their presence means for the assembly, function, and evolution of the cell division apparatus is not known; but with newly available information and probes, these are questions that can finally be addressed. The present article summarizes the history of this field, what we know about the molecules in question, and in light of these findings, emphasizes the need to view the cell division apparatus for what it is by definition, a ribonucleoprotein complex.