Joseph O'Tousa

My research program examines the biochemical mechanisms and genetic causes underlying degeneration of photoreceptors, the sensory cells responsible for light reception. First, we are using genetic approaches in Drosophila to identify the molecular components and pathway responsible for rhodopsin movement in the cell. We have shown that normal rhodopsin transport to the light sensitive membranes and proper recycling processes are essential for photoreceptor health. The results have shown that biochemical pathways and mechanisms are shared by invertebrate and vertebrate photoreceptors. Thus, our work contributes to the understanding of the inherited retinal diseases that afflict human populations.

 

Currently, the laboratory is also investigating how rhodopsin expression specifies the neurobiology of other invertebrates. Recently we showed that conserved expression of rhodopsins within the R7 class of photoreceptors in three different mosquito species suggest that they share common visually based behavioral strategies despite having diverged 150 million years ago. However, we also have shown that there are some differences in rhodopsin expression and the retinal organization of these species. We are therefore interested in investigating how these variations support species-specific behaviors.

 

For information about the O'Tousa lab, please visit: http://nd.edu/~jotousa/labwww/

 

Nicodemus, J., O’Tousa J, E., and Duman, J. G. (2006). Expression of a Beetle, Dendroides canadensis, antifreeze protein in Drosophila melanogaster. J Insect Physiol. 52: 888-96.

 

Ahmad, S. T., Joyce, M. V., Boggess, B., and O’Tousa, J. E. (2006). The role of Drosophila ninaG oxidoreductase in visual pigment chromophore biogenesis. J Biol Chem 281, 9205-9.

 

Ahmad, S. T., Natochin, M., Barren, B., Artemyev, N.O. and O’Tousa, J.E. (2006). Heterologous expression of bovine rhodopsin in Drosophila photoreceptor cells. Invest Ophthalmol Vis Sci 47: 3722-8.

 

Natochin, M., Barren, B., Ahmad, S. T., O’Tousa, J. E., and Artemyev, N. O. (2006) Probing rhodopsin-transducin interaction using Drosophila Rh1-bovine rhodopsin chimeras. Vision Research 46: 4575-81.

 

Ahmad, S. T., Natochin, B., Artemyev, N.O. and O’Tousa, J.E. (2007). The Drosophila rhodopsin cytoplasmic tail domain is required for maintenance of rhabdomere structure. FASEB J. 21: 449-55

 

Yang, J. and O’Tousa, J.E. (2007) Cellular sites of Drosophila NinaB and NinaD activity in vitamin A metabolism. Mol. And Cell. Neurosci. 35: 49-56.

 

Hu X, England JH, Lani AC, Tung JJ, Ward NJ, Adams SM, Barber KA, Whaley MA, O'Tousa JE (2009) Patterned rhodopsin expression in R7 photoreceptors of mosquito retina: Implications for species-specific behavior. J Comp Neurol 516:334-342.

 

Mecklenburg KL, Takemori, N, Komori N, Chu B, Hardie RC, Matsumoto H, and O'Tousa JE (2009) Retinophilin is a light-regulated phosphoprotein required to suppress photoreceptor dark noise in Drosophila. J. Neuroscience (in press).