Article | Published:

Complex interactions between genes controlling trafficking in primary cilia

Nature Genetics volume 43, pages 547553 (2011) | Download Citation

Abstract

Cilia-associated human genetic disorders are striking in the diversity of their abnormalities and their complex inheritance. Inactivation of the retrograde ciliary motor by mutations in DYNC2H1 causes skeletal dysplasias that have strongly variable expressivity. Here we define previously unknown genetic relationships between Dync2h1 and other genes required for ciliary trafficking. Mutations in mouse Dync2h1 disrupt cilia structure, block Sonic hedgehog signaling and cause midgestation lethality. Heterozygosity for Ift172, a gene required for anterograde ciliary trafficking, suppresses cilia phenotypes, Sonic hedgehog signaling defects and early lethality of Dync2h1 homozygotes. Ift122, like Dync2h1, is required for retrograde ciliary trafficking, but reduction of Ift122 gene dosage also suppresses the Dync2h1 phenotype. These genetic interactions illustrate the cell biology underlying ciliopathies and argue that mutations in intraflagellar transport genes cause their phenotypes because of their roles in cilia architecture rather than direct roles in signaling.

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Acknowledgements

We thank R. Vallee (Columbia University College of Physicians and Surgeons) for the Dync2h1 antibody, R. Rohatgi and M. Scott (Stanford University) for expression constructs used to generate antibodies against Smo and Ptch1, and S. Weatherbee for help in antibody production. We thank B. Yoder (University of Alabama at Birmingham) for the mouse Ift88 conditional allele and A. Joyner (Memorial Sloan-Kettering Cancer Center (MSKCC)) for Gli2 and Gli3XtJ mice. We acknowledge N. Lampen (MSKCC Electron Microscopy Facility) for technical support with scanning electron microscopy; Z. Lazar, Y. Romin and S. Fujisawa (MSKCC Molecular Cytology Core) for assistance with confocal microscopy and MetaMorph analysis, and S. Galdeen (Rockefeller University Bio-Imaging Resource Center) for assistance with DeltaVision microscopy. We are grateful to members of the Anderson lab and Timothy Bestor (Columbia University Medical Center) for helpful discussions and critical reading of the manuscript. We obtained monoclonal antibodies from the Developmental Studies Hybridoma Bank, which was developed under the auspices of the National Institute of Child Health and Human Development and is maintained by the Department of Biological Sciences, University of Iowa. This work was supported by the US National Institutes of Health R01 NS044385 to K.V.A.

Author information

Author notes

    • Polloneal Jymmiel R Ocbina

    Current address: Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA.

Affiliations

  1. Developmental Biology Program, Sloan-Kettering Institute, New York, New York, USA.

    • Polloneal Jymmiel R Ocbina
    •  & Kathryn V Anderson
  2. Neuroscience Program, Weill Graduate School of Medical Sciences, Cornell University, New York, New York, USA.

    • Polloneal Jymmiel R Ocbina
  3. Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.

    • Jonathan T Eggenschwiler
  4. Department of Pediatrics, The University of Chicago, Chicago, Illinois, USA.

    • Ivan Moskowitz
  5. Department of Pathology, The University of Chicago, Chicago, Illinois, USA.

    • Ivan Moskowitz

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Contributions

P.J.R.O. and K.V.A. conceived the experiments and wrote the manuscript. P.J.R.O. performed the experiments. J.T.E. helped write the manuscript and provided reagents. I.M. provided reagents.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Kathryn V Anderson.

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DOI

https://doi.org/10.1038/ng.832

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