Profiles

Anique Olivier-Mason

Graduate Student

B.A., Oberlin College, 1999

aniqueom [at] brandeis.edu

After graduating from Oberlin College in 2002, I worked for the City of New York in a forensic Biology lab (NYC OCME) until beginning my graduate studies at Brandeis in 2006. I joined the Sengupta lab the next year and now currently study the mechanisms generating ciliary structural diversity in C. elegans.

Research Interests

Cells necessary for hearing and olfaction possess distinct and highly specialized ciliary structures that are critical for their functions

Cilia are present in almost all mammalian cell types¹, and are particularly critical for olfaction, sight and hearing. Most primary cilia are cylindrical structures with a 9+0 microtubule arrangement. Although primary cilia present on most cell types exhibit relatively simple structures, sensory cell types exhibit highly specialized cilia structures. For instance, in the ear, the kinocilium is a microtubule based structure with a defined morphology², and in the olfactory epithelium, olfactory neurons contain multiple elongated cilia emanating from a dendritic knob³. Photoreceptors in the eye also contain highly specialized cilia structures⁴. These structures are absolutely essential for the specialized sensory functions of these cell types. Defects in these cilia structures result in loss of sensory functions and syndromes such as anosmia and hearing loss^5,6.

Using C. elegans to study the mechanisms of specialized chemosensory cilia formation

C. elegans is an ideal model organism for studying the formation and function of sensory cilia. ~60 sensory neurons contain primary cilia, and a subset of these cilia exhibit highly diverse morphologies (See Figure 2)^7,8. These specialized cilia are essential for the correct chemosensory functions of these neuron types⁹. Work has shown that the molecular mechanisms required for cilia formation in C. elegans are highly conserved in higher organisms^5,6.

Recent work from our lab is beginning to elucidate the mechanisms by which sensory cell-type cilia are formed. We have shown that the channel and AWB wing cilia types differ in the critical process of intraflagellar transport (IFT)¹⁰. Determined by measuring IFT velocities, the two anterograde motors, OSM-3 and Kinesin II, have unique functions in the channel cilia but exhibit partly redundant functions in the wing cilia¹⁰. Moreover, sensory signaling appears to play a role in the maintenance of wing, but not channel cilia¹¹. Several genes encoding IFT proteins are expressed in only a subset of the ciliated cells in C. elegans indicating that those proteins may have type-specific cilia functions (^12,13 and Hurd and Portman personal communication).

Together with a postdoctoral fellow in our lab, David Doroquez, I am using a biochemical and genetic approach to understand how specialized cilia are formed. In a biochemical approach, we are co-immunoprecipitating components of the IFT complex and identifying proteins necessary for cell specific differences in cilia morphology via mass spectrometry (in collaboration with the Yates lab at Scripps). We have verified that known IFT components can be identified by this approach, and I am currently exploring the roles of additional interesting proteins that we have identified. In a genetic approach, I am using forward and reverse genetic screens to identify genes required for the differentiation of cell-specific cilia. Given the high degree of conservation in ciliary mechansims across species, I hope that my work will provide insights into the causes of ciliary dysfunction and disorders in other animals.

Outside the lab

I really enjoy hiking and other outdoor activities especially in Maine and New Hampshire (my home state). The picture below was taken in Acadia National Park.

References:

1. Wheatley, D.N. Primary cilia in normal and pathological tissues. Pathobiology 63, 222-38 (1995).

2. Kikuchi, T., Takasaka, T., Tonosaki, A. & Watanabe, H. Fine structure of guinea pig vestibular kinocilium. Acta Otolaryngol 108, 26-30 (1989).

3. Reese, T. Olfactory cilia in the frog. J Cell Biol 25, 209-230 (1965).

4. Steinberg, R.H. & Wood, I. Clefts and microtubules of photoreceptor outer segments in the retina of the domestic cat. J Ultrastruct Res 51, 307-403 (1975).

5. Jones, C. et al. Ciliary proteins link basal body polarization to planar cell polarity regulation. Nat Genet 40, 69-77 (2008).

6. Kulaga, H.M. et al. Loss of BBS proteins causes anosmia in humans and defects in olfactory cilia structure and function in the mouse. Nat Genet 36, 994-8 (2004).

7. Perkins, L.A., Hedgecock, E.M., Thomson, J.N. & Culotti, J.G. Mutant sensory cilia in the nematode Caenorhabditis elegans. Dev Biol 117, 456-87 (1986).

8. Ward, S., Thomson, N., White, J.G. & Brenner, S. Electron microscopical reconstruction of the anterior sensory anatomy of the nematode Caenorhabditis elegans.?2UU. J Comp Neurol 160, 313-37 (1975).

9. Inglis, P.N., Ou, G., Leroux, M.R. & Scholey, J.M. The sensory cilia of Caenorhabditis elegans. WormBook, 1-22 (2007).

10. Mukhopadhyay, S. et al. Distinct IFT mechanisms contribute to the generation of ciliary structural diversity in C. elegans. Embo J 26, 2966-80 (2007).

11. Mukhopadhyay, S., Lu, Y., Shaham, S. & Sengupta, P. Sensory signaling-dependent remodeling of olfactory cilia architecture in C. elegans Developmental Cell In press(2008).

12. Efimenko, E. et al. Caenorhabditis elegans DYF-2, an orthologue of human WDR19, is a component of the intraflagellar transport machinery in sensory cilia. Mol Biol Cell 17, 4801-11 (2006).

13. Bacaj, T., Lu, Y. & Shaham, S. The conserved proteins CHE-12 and DYF-11 are required for sensory cilium function in Caenorhabditis elegans. Genetics 178, 989-1002 (2008)