The molecular architecture of axonemes revealed by cryoelectron tomography

Daniela Nicastro, Cindi Schwartz, Jason Pierson, Richard Gaudette, Mary E. Porter, J. Richard McIntosh

Research output: Contribution to journalArticle

486 Scopus citations


Eukaryotic flagella and cilia are built on a 9 + 2 array of microtubules plus >250 accessory proteins, forming a biological machine called the axoneme. Here we describe the three-dimensional structure of rapidly frozen axonemes from Chlamydomonas and sea urchin sperm, using cryoelectron tomography and image processing to focus on the motor enzyme dynein. Our images suggest a model for the way dynein generates force to slide microtubules. They also reveal two dynein linkers that may provide "hard-wiring" to coordinate motor enzyme action, both circumferentially and along the axoneme. Periodic densities were also observed inside doublet microtubules; these may contribute to doublet stability.

Original languageEnglish (US)
Pages (from-to)944-948
Number of pages5
Issue number5789
StatePublished - Aug 18 2006


Cite this

Nicastro, D., Schwartz, C., Pierson, J., Gaudette, R., Porter, M. E., & McIntosh, J. R. (2006). The molecular architecture of axonemes revealed by cryoelectron tomography. Science, 313(5789), 944-948.