Structural inheritance in Paramecium: ultrastructural evidence for basal body and associated rootlets polarity transmission through binary fission.

One main difference between basal bodies and centrioles resides in the expression of their polarity: centrioles display a structural nine-fold radial symmetry, whereas basal bodies express a circumferential polarity, thanks to their asymmetric set of rootlets. The origin of this polarity during organelle duplication still remains under debate: is it intrinsic to the nine-fold structure itself (i.e.