Maurice Kernan attended the University of Dublin and received a B.A. in Genetics in 1984. He went on to obtain a Ph.D. in Genetics from the University of Wisconsin in 1990. He then spent three years as a Research Associate at the Howard Hughes Medical Institute, University of California, San Diego. He came to Stony Brook University in 1995 where he is currently Associate Professor of Neurobiology & Behavior. He has served as the Director of the HHMI summer undergraduate research program since 2007.
Our research combines Drosophila genetics, molecular biology and electrophysiology to investigate the cellular and molecular basis for the mechanical senses: touch, hearing and proprioception. We focus on mechanosensory signaling in ciliated sensory neurons and in sperm flagella, using genetics to discover their molecular working parts, in particular the mechanically-activated ion channels that convert touch and sound into electrical receptor potentials. Flies are ideal for getting to grips with mechanosensation: in addition to their powerful genetics, they bear thousands of mechanosensory bristles, each innervated by a single neuron, with striking physiological similarities to the sensory cells in the human ear. We begin with behavioral mutants that are touch-insensitive, uncoordinated and/or deaf. Electrophysiological recordings from bristles and from the fly’s antennal ear confirmed the sensory defects in the mutant flies, while gene mapping and sequencing enable us to identify the defective proteins, even when these are rare or novel. Signal-transducing proteins that we have discovered include an extracellular protein that links neuronal sensory endings to bristles, and the first sound-transducing channels to be identified in any organism.
The neuronal sensory ending is a modified cilium, a cell-surface compartment with its own signaling and transport systems. The cilium/basal body/centriole complex is found throughout the eukaryotes; primary cilia on human cells, long seen as vestigial, have now been implicated in developmental signaling and in diseases such as polycystic kidney disease. Several mechanosensory mutants with defective cilia affect components of a conserved intraflagellar transport (IFT) protein complex. A novel centriole-associated protein required in both ciliated neurons and sperm cells is yielding insights into a long-standing problem in cell biology: the conversion of a mitotic centriole into the ciliogenic basal body.
Mutations in human polycystins, ciliary mechanosensory channel proteins, also lead to polycystic kidney disease. In Drosophila, polycystin proteins are located on the sperm flagellum. A polycystin mutant is male-sterile: mutant sperm are motile, but fail to enter female sperm storage organs after mating. We are now using fly sperm as a genetic system to study polycystin signaling; the Drosophila polycystins may provide the first clue to the molecular mechanism mediating sperm competition, a bizarre arena of intense selective pressures and significant evolutionary impact.
- S. Yorozu, A. Wong, B.J. Fischer, H. Dankert, M.J. Kernan, A. Kamikouchi, K. Ito and D.J. Anderson (2009). Distinct sensory representations of wind and near-field sound in the Drosophila brain. In press, Nature.
- E. Lee, E. Sivan-Loukianova, D.F. Eberl and M.J. Kernan. (2008) An IFT-A protein is required to delimit functionally distinct zones in mechanosensory cilia. Current Biology 18 1899-906.
- A.E. Coluccio, R. Rodriguez, M. Kernan and A. M. Neiman (2008). The yeast spore wall enables spores to survive passage through the digestive tract of Drosophila. PLoS ONE , 3 (8):e2873.
- M. J. Kernan (2007) Mechanotransduction and auditory transduction in Drosophila. Pflugers Arch - Eur. J. Physiol. 454, 703-20.
- S. L. Elliott, C. F. Cullen, N. Wrobel, M. J. Kernan, H. Ohkura (2005). EB1 is essential during Drosophila development and plays a crucial role in the integrity of chordotonal mechanosensory organs. Molecular Biology of the Cell 16 891-901. (PubMed)
- M.B. Goodman, E.A. Lumpkin, A. Ricci, W.D. Tracey, M. Kernan, T. Nicolson (2004). Molecules and mechanisms of mechanotransduction. Journal of Neuroscience 24, 9220-2. (PubMed)
- Z. Gong, W. Son, Y. D. Chung, J. Kim, D. W. Shin, C.A. McClung, Y.Lee, H. W. Lee, D-J. Chang, B-K. Kaang, H. Cho, U. Oh, J. Hirsh, M. J. Kernan, C. Kim (2004). Two interdependent TRPV channel subunits, Inactive and Nanchung, mediate hearing in Drosophila. Journal of Neuroscience. 24, 9059-66. (PubMed)
- J. D. Baker, S. Adhikarakunnathu, & M. J. Kernan (2004). Mechanosensory-defective, male-sterile unc mutants identify a novel coiled-coil protein required for ciliogenesis in Drosophila. Development, 131, 3411-3422. (PubMed)
- Martinez-Campos M, R. Basto R, J. Baker J, M. Kernan M, J.W. Raff (2004). The Drosophila pericentrin-like protein is essential for cilia/flagella function, but appears to be dispensable for mitosis. Journal of Cell Biology 165, 673-83. (PubMed)
- T.J. Watnick, Y. Jin, E. Matunis, M.J. Kernan, C. Montell (2003). A flagellar polycystin-2 homolog required for male fertility in Drosophila. Current Biology, 13 2179-2184. (PubMed)
- Y-G. Han, H. Kwok, & M. J. Kernan (2003). Intraflagellar transport is required to differentiate sensory cilia but not sperm in Drosophila. Current Biology, 13, 1679 – 1686. (PubMed)
- J. Kim, Y. D. Chung, D. Park, S. K. Choi, D. W. Shin, H. Soh, H. W. Lee, W. Son, J. Yim, C-S. Park, M. J. Kernan, & C. Kim (2003). A TRPV family ion channel required for hearing in Drosophila. Nature 424, 81-4. (PubMed)
- R. Dubruille, A. Laurençon, C. Vandaele, E. Shishido, M. Coulon-Bublex, P. Swoboda, P. Couble, M. Kernan, B. Durand (2002). Drosophila regulatory factor X is necessary for ciliated neuron differentiation. Development, 129 (23): 5487-5498. (PubMed)
- Y.D. Chung, J. Zhu, Y-G. Han, M. J. Kernan (2001). nompA encodes a PNS-specific ZP-domain protein required to connect mechanosensory dendrites to sensory structures. Neuron 29, 415-428. (PubMed)
- D. F. Eberl, R.W. Hardy M. J. Kernan (2000). Genetically related transduction mechanisms for hearing and touch in Drosophila. Journal of Neuroscience 20 (16) 5981-5988. (PubMed)
Pubmed Linked Publications
- James Baker - Research Scientist
- Shao-Kuei Huang - Graduate Student (Neuroscience)
- Nan Wang - Undergraduate