Maurice Kernan
Associate Professor
PhD, University of Wisconsin
477 Centers for Molecular Medicine (CMM)
Office Phone: (631) 632-9964
Lab Phone: (631) 632-9182
Training
Maurice Kernan attended the University of Dublin, Ireland, graduating with a B.A. in Natural Sciences (Genetics) in 1984. He came to the USA to do graduate work at the University of Wisconsin-Madison on Drosophila neurogenetics, receiving his Ph.D. in 1990; his thesis on the unexpected involvement of a mutation affecting sodium channels with the X chromosome dosage compensation mechanism received the Sandler Award of the Genetics Society of America. He went on to a HHMI postdoctoral fellowship at University of California, San Diego, where he began to develop Drosophila as a mechanosensory genetic system. He brought this work to Stony Brook and joined the Department faculty in 1995.
Research Interests
Mechanosensory genetics and protein discovery
Research in the Kernan lab combines Drosophila molecular genetics and sensory electrophysiology to investigate the cellular and molecular basis for the mechanical senses: touch, hearing and proprioception. Flies bear thousands of bristles and other mechanoreceptor organs, each innervated by the ciliated ending of a sensory neuron: single-cell receptor potentials can be evoked and electrophysiologically recorded via bristle shafts, and compound sound-evoked potentials from the antennal nerve. Mutant no mechanoreceptor potential (nomp) flies that lack these responses enabled us to discover proteins that build the mechanosensory cilia and transduce physical stimuli into electrical receptor potentials. These include a matrix protein that links neuronal sensory endings to external structures, components of the intraflagellar transport (IFT) complex, and TRPN and TRPV ion channel proteins.
Alternative splicing of a mechanotransducer channel pore
A TRPN ion channel encoded in Drosophila by the nompC gene is the core transducer element in many mechanoreceptor organs. Its pore domain is encoded by two paralogous exons, which are switched by alternative splicing to produce channel isoforms that generate slow-adapting or fast-adapting receptor potentials. Splice-reporter versions of nompC reveal that phasic or vibrosensory neurons specifically express the fast-adapting form whereas tonic, proprioceptive neurons express the slower-adapting form. Current work aims to find out how this splice switch is regulated in neuronal subtypes, and if voltage-gated and calcium-activated channels that also have paralogous alternative pore exons are coregulated with nompC to tune neuronal response.
Mechanoreceptor evolution: a trigger of insect hyperdiversity?
Comparative analyses of NompC/TRPN gene structure show that paralogous alternative pore exons arose independently at least five times early in insect evolution, including in each of the hyperdiverse Holometabolan groups: Diptera + Lepidoptera (flies, moths and butterflies); Coleoptera (beetles); and Hymenoptera (wasps, ants and bees). In each case, the pore paralogs arose early and are conserved across the taxon. Most insects use sound or vibration signals, sensed by TRPN-based mechanoreceptors, to attract and identify conspecific mates; we suggest that TRPN pore exon duplication and diversification could have triggered early bursts of speciation by enhancing mechanoreceptor sensitivity to variation in courtship signals.
Publications
Y. Sharma, J. S. Jacobs, E. Sivan-Loukianova, E. Lee, M.J. Kernan, & D.F. Eberl (2023). The Drosophila retrograde IFT motor, cytoplasmic dynein heavy chain 1b, is required for normal mechanosensory function. Frontiers in Molecular Neuroscience 16; doi.org/10.3389/fnmol.2023.1263411
S.Karak, J. S. Jacobs, M.Kittelmann1, C.Spalthoff, R. Katana, E. Sivan-Loukianova, M.S. Schon, M.J. Kernan, D.F. Eberl, & M.C. Göpfert. (2015). Diverse roles of axonemal dyneins in Drosophila auditory neuron function and mechanical amplification in hearing. Scientific Reports. 5, 17085; doi 10.1038/srep17085.
M.M. Mirrione, N. Ruth, D. Alexoff, J. Logan, J. Fowler & M. Kernan (2014). Positron emission tomography (PET) and graphical kinetic analysis of the dopamine neurotransmitter system: an exercise for an undergraduate laboratory course. Journal of Undergraduate Neuroscience Education, 12 (2) A114-A122.
C. Enjolras, J. Thomas, B. Chhin, E. Cortier, J-L. Duteyrat, F. Soulavie, M.J. Kernan, A. Laurençon & B. Durand. (2012) Chibby is required in Drosophila for centriole to basal body maturation, but not for wingless signaling. J. Cell Biology. (2): 313-25.
D.F. Eberl & M.J. Kernan (2011). Recording sound-evoked potentials from Drosophila antennal nerves. Cold Spring Harbor Protocols, Mar 1;2011(1):prot5576
R. Kavlie, M.J. Kernan & D.F. Eberl, (2010) Hearing in Drosophila requires TilB, a conserved protein associated with ciliary motility. Genetics 185, 175-188.
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. Nature 458, 201-205
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)
M. Kernan. (1997). The molecular basis of the mechanical senses: one mechanism or many? Journal of NIH Research 9, 32-36.
M. Kernan and C. Zuker (1995). Genetic approaches to mechanosensory transduction. Curr. Opin. Neurobiology 5 443-448.
M. Kernan, D. Cowan and C. Zuker (1994). Genetic dissection of mechanotransduction: mechanoreception-defective mutations of Drosophila. Neuron 12 1195-1206.
M. I. Kuroda, M. J. Kernan, R. Kreber, B. Ganetzky, and B. S. Baker (1991). The maleless protein associates with the X chromosome to regulate dosage compensation in Drosophila. Cell 66 935-947.
M. J. Kernan, M. I. Kuroda, R. Kreber, B. S. Baker and B. Ganetzky (1991). napts, a mutation affecting sodium channel activity in Drosophila, is an allele of mle, a regulator of X chromosome transcription. Cell 66 949-959