Assistant Research Professor

(574) 631-2895
tbailey@nd.edu

2000	Brigham Young University Provo, UT	M.S. Microbiology
	Thesis Title: Effects of Follicular Dendritic Cells on HIV Infected T Cells
	under Gregory F. Burton
2006	Baylor College of Medicine Houston, TX	Ph.D. Developmental Biology
	Thesis Title: Regulation of vertebrate eye development by Rx genes
	under Milan Jamrich
Present	University of Notre Dame, Center for Zebrafish Research	Postdoctoral Research Fellow
	Project: Molecular and Genetic Analysis of Retinal Regeneration in Danio rerio
	under David R. Hyde

My interests revolve around the development of organ tissue (in particular, the neuronal tissue of the retina). Using ethylnitosourea induce genetic mutations, fish which fail to properly develop eyes have been generated which start to generate retinal tissue, but fail after the process of lens induction. I am characterizing these mutants.

I am further interested in the molecular mechanisms of stress-induced cell death and regeneration. In response to tissue damage, stressed or dying cells direct a signal(s) to native stem cells in order to effect the repair damaged tissue. In the case of the damaged retina, these stem cells appear to be responsive Müller glia. Our lab has characterized apoptotic responses when the retina is given insults that damage specifically the outer or inner retina. Characterization of the cellular interactions between dying cells and cells that respond to their signal(s) promises insights into the methods by which tissue naturally repairs itself.

I combine these interests by researching how regeneration compares to normal development. Regeneration is the process of replacing distinct, lost cell types that have unique attributes. Our lab has described the ability of adult stem cell populations to differentiate, in a similar manner to early development, into particular cells lost during the degenerative/injury phase. Regeneration differs from ontogeny in that often only as subset of cell types generated by the ontological stem cells are needed in a regenerative response. Little is known how this process is regulated. Genes that are both necessary and sufficient for eye generation have been well studied, but little is known about their role in regeneration. Teleost fish present model systems in which molecular and genetic tools can be applied to this question.

Vihtelic T.S. et al. (2002) Vis. Res. 42:535-540

Figure 1. Early retina developmental defects in the bst and gef mutants result in extremely small eyes. Panels A and C are sections of wild type eyes at 3 and 6 dpf, respectively. Panel B shows the bst mutant at 3 dpf. The retina consists of only a few cells, while the lens has a wild type structure for this age. The gef mutant at 6 dpf is shown in panel D. A relatively few cells also characterize the gef retina. Arrowheads denote a small area of organized cells that may correspond to the photoreceptor layer. The gef mutant lens remains healthy, unlike the bst lens, which has degenerated by this age. Abbreviations: PL, photoreceptor layer; INL, inner nuclear layer; GCL, ganglion cell layer; R, retina. The scale bars (50 um) in panels A and B also apply to panels C and D, respectively.

1. Bailey, T.J., El-Hodiri, H., Zhang, L., Shah, R., Mathers, P.H., and Jamrich, M. (2004). Regulation of vertebrate eye development by Rx genes. Int J Dev Biol. 48(8-9): 761-70.

2.  Wang J., Cortina, G., Wu S.V., Tran, R., Cho, J., Tsai, M.J., Bailey, T.J., Jamrich, M., Ament, M.E., Treem, W.R., Hill, I.D., Vargas, J.H., Gershman, G., Farmer D.G., Reyen, L., Martin, M.G. (2006). Mutant neurogenin-3 in congenital malabsorptive diarrhea. NEJM.  355(3): 236-9.

3.  Swindell, E.C., Bailey, T.J., Loosli, F., Liu, C., Amaya-Manzanares, F., Mahon, K.A., Wittbrodt, J., Jamrich, M. (2006). Rx-Cre, a tool for inactivation of gene expression in the developing retina. Genesis 44(8):361-3.

4. Thummel, R., Enright, J.M., Kassen, S.C., Montgomery, J.E., Bailey, T.J., and Hyde, D.R. (2010). Pax6a and Pax6b control novel regulatory points during neuronal progenitor cell proliferation in the regenerating zebrafish retina. Exp. Eye Res. 90: 572-582.

5. Bailey, T.J., Fossum, S.L., Fimbel, S.M., Montgomery, J.E., and Hyde, D.R. (2010). The inhibitor of phagocytosis, O-phospho-L-serine, suppresses Müller glia proliferation and cone cell regeneration in the light-damaged zebrafish retina. Exp. Eye Res. 91: 601-612.

6. Thummel, R. Bailey, T.J., and Hyde, D.R. (2011) In vivo electroporation of morpholinos into the adult zebrafish retina. J. Vis. Exp. 58, e3603. DOI: 10.3791/3603 (2011).