Ann C. Morris

acmo224's picture
  • Associate Professor
  • Biology
  • Cell and Developmental Biology
  • Genetics and Genomics
  • Neuroscience and Neurobiology
215 T.H. Morgan Building
Research Interests:

B.S., Biochemistry, Florida State University, 1995
Ph.D., Genetics and Molecular Biology, Emory University, 2001
Postdoctoral fellow, Institute of Human Genetics, Montpellier, France, 2001-2002
Postdoctoral associate, Florida State University, Department of Biological Sciences, 2002-2009


Development and regeneration in the vertebrate retina

My research involves studying cellular differentiation and gene expression in the vertebrate retina, the photosensitive lining at the back of the eye. The light-capturing neurons of the retina are the photoreceptors. Rod photoreceptors mediate dim light vision, whereas cone photoreceptors mediate daytime and color vision.

Photoreceptor degeneration associated with ocular diseases such as retinitis pigmentosa (RP), macular degeneration, and retinal detachment is a significant cause of visual impairment and blindness, for which there is currently no cure. One promising avenue of research is to study the retinas of vertebrate animals that innately possess the capacity to regenerate retinal neurons following injury. For this reason, the zebrafish retina represents a valuable model system in which to study the mechanisms of neural progenitor proliferation, differentiation, and photoreceptor regeneration.The zebrafish is a small, freshwater teleost that is easily reared in the laboratory. Zebrafish offer several advantages for genetic and developmental studies, including robust reproduction, optical transparency of the embryo, and rapid development. Relevant to my research, zebrafish (like humans) are diurnal animals, and the zebrafish retina contains a large number of cones in addition to rods, which is advantageous for studying daytime and color vision. Some of the methods I use to study the zebrafish visual system include standard molecular, biochemical and immunohistochemical techniques, as well as a variety of more sophisticated genetic and molecular methods such as transgenesis, forward and reverse genetic approaches, and the creation of genetic mosaics.

The ability of the teleost retina to regenerate following injury has been known for many years. Regeneration of the damaged retina involves three basic phases. First, there must be an increase in proliferation of germinal cells. Second, the progenitor cells must receive the appropriate signals from the local environment directing them to migrate and differentiate into the missing cell type. And finally, the newly differentiated neurons must integrate into the existing retinal circuitry. As this is precisely the sequence of events that must take place for cell-based transplantation therapies to be successful in the human retina, it is important to learn how each of these steps is controlled in zebrafish. Accordingly, many of the projects in my laboratory involve identifying the genetic pathways that mediate photoreceptor development and regeneration in zebrafish. Overall, my research spans several areas of interest, including developmental neurobiology, genetics, molecular, and cellular biology.

Keywords: retina, zebrafish, vision, eye, development


PubMed Publications*: 
  • Titialii-Torres, KF ;Morris, AC "Embryonic hyperglycemia perturbs the development of specific retinal cell types, including photoreceptors." Journal of cell science 135, 1 (2022): Details. Full text
  • Krueger, LA ;Morris, AC "Generation of a zebrafish knock-in line expressing MYC-tagged Sox11a using CRISPR/Cas9 genome editing." Biochemical and biophysical research communications 608, (2022): 8-13. Details. Full text
  • Connor, B ;Titialii-Torres, K ;Rockenhaus, AE ;Passamonte, S ;Morris, AC ;Lee, YS "Biliverdin regulates NR2E3 and zebrafish retinal photoreceptor development." Scientific reports 12, 1 (2022): 7310. Details. Full text
  • Petersen, RA ;Morris, AC "Visualizing Ocular Morphogenesis by Lightsheet Microscopy Using rx3:GFP Transgenic Zebrafish." Journal of visualized experiments : JoVE 170 (2021): Details. Full text
  • Hentig, J ;Cloghessy, K ;Lahne, M ;Jung, YJ ;Petersen, RA ;Morris, AC ;Hyde, DR "Zebrafish Blunt-Force TBI Induces Heterogenous Injury Pathologies That Mimic Human TBI and Responds with Sonic Hedgehog-Dependent Cell Proliferation across the Neuroaxis." Biomedicines 9, 8 (2021): Details. Full text
  • Coomer, CE ;Wilson, SG ;Titialii-Torres, KF ;Bills, JD ;Krueger, LA ;Petersen, RA ;Turnbaugh, EM ;Janesch, EL ;Morris, AC "Her9/Hes4 is required for retinal photoreceptor development, maintenance, and survival." Scientific reports 10, 1 (2020): 11316. Details. Full text
  • Jang, H ;Oakley, E ;Forbes-Osborne, M ;Kesler, MV ;Norcross, R ;Morris, AC ;Galperin, E "Hematopoietic and neural crest defects in zebrafish shoc2 mutants: a novel vertebrate model for Noonan-like syndrome." Human molecular genetics 28, 3 (2019): 501-514. Details. Full text
  • Coomer, CE ;Morris, AC "Capn5 Expression in the Healthy and Regenerating Zebrafish Retina." Investigative ophthalmology & visual science 59, 8 (2018): 3643-3654. Details. Full text
  • Wilson, SG ;Wen, W ;Pillai-Kastoori, L ;Morris, AC "Tracking the fate of her4 expressing cells in the regenerating retina using her4:Kaede zebrafish." Experimental eye research 145, (2016): 75-87. Details. Full text
  • Pillai-Kastoori, L ;Wen, W ;Morris, AC "Keeping an eye on SOXC proteins." Developmental dynamics : an official publication of the American Association of Anatomists 244, 3 (2015): 367-376. Details. Full text
  • Wen, W ;Pillai-Kastoori, L ;Wilson, SG ;Morris, AC "Sox4 regulates choroid fissure closure by limiting Hedgehog signaling during ocular morphogenesis." Developmental biology 399, 1 (2015): 139-153. Details. Full text
  • Pillai-Kastoori, L ;Wen, W ;Wilson, SG ;Strachan, E ;Lo-Castro, A ;Fichera, M ;Musumeci, SA ;Lehmann, OJ ;Morris, AC "Sox11 is required to maintain proper levels of Hedgehog signaling during vertebrate ocular morphogenesis." PLoS genetics 10, 7 (2014): e1004491. Details. Full text
  • Forbes-Osborne, MA ;Wilson, SG ;Morris, AC "Insulinoma-associated 1a (Insm1a) is required for photoreceptor differentiation in the zebrafish retina." Developmental biology 380, 2 (2013): 157-71. Details. Full text
  • Morris, AC "The genetics of ocular disorders: insights from the zebrafish." Birth defects research. Part C, Embryo today : reviews 93, 3 (2011): 215-28. Details. Full text
  • Morris, AC ;Forbes-Osborne, MA ;Pillai, LS ;Fadool, JM "Microarray analysis of XOPS-mCFP zebrafish retina identifies genes associated with rod photoreceptor degeneration and regeneration." Investigative ophthalmology & visual science 52, 5 (2011): 2255-66. Details. Full text
  • Alvarez-Delfin, K.;Morris, AC ;Snelson, CD ;Gamse, JT ;Gupta, T.;Marlow, FL ;Mullins, MC ;Burgess, HA ;Granato, M.;Fadool, JM "Tbx2b is required for ultraviolet photoreceptor cell specification during zebrafish retinal development." Proceedings of the National Academy of Sciences of the United States of America 106, 6 (2009): 2023-8. Details. Full text
  • Morris, AC ;Scholz, TL ;Brockerhoff, SE ;Fadool, JM "Genetic dissection reveals two separate pathways for rod and cone regeneration in the teleost retina." Developmental neurobiology 68, 5 (2008): 605-19. Details. Full text
  • Morris, AC ;Schroeter, EH ;Bilotta, J.;Wong, RO ;Fadool, JM "Cone survival despite rod degeneration in XOPS-mCFP transgenic zebrafish." Investigative ophthalmology & visual science 46, 12 (2005): 4762-71. Details. Full text
  • Morris, AC ;Fadool, JM "Studying rod photoreceptor development in zebrafish." Physiology & behavior 86, 3 (2005): 306-13. Details. Full text
  • Morris, AC ;Beresford, GW ;Mooney, MR ;Boss, JM "Kinetics of a gamma interferon response: expression and assembly of CIITA promoter IV and inhibition by methylation." Molecular and cellular biology 22, 13 (2002): 4781-91. Details. Full text
  • Morris, AC ;Spangler, WE ;Boss, JM "Methylation of class II trans-activator promoter IV: a novel mechanism of MHC class II gene control." Journal of immunology (Baltimore, Md. : 1950) 164, 8 (2000): 4143-9. Details. Full text
  • Moreno, CS ;Beresford, GW ;Louis-Plence, P.;Morris, AC ;Boss, JM "CREB regulates MHC class II expression in a CIITA-dependent manner." Immunity 10, 2 (1999): 143-51. Details. Full text
  • Morris, AC ;Riley, JL ;Fleming, WH ;Boss, JM "MHC class II gene silencing in trophoblast cells is caused by inhibition of CIITA expression." American journal of reproductive immunology (New York, N.Y. : 1989) 40, 6 (1998): 385-94. Details. Full text
  • Piedade, WP ;Titialii-Torres, K ;Morris, AC ;Famulski, JK "Proteasome-Mediated Regulation of Cdhr1a by Siah1 Modulates Photoreceptor Development and Survival in Zebrafish." Frontiers in cell and developmental biology 8, (0): 594290. Details. Full text
  • Morris, AC ;Scholz, T.;Fadool, JM "Rod progenitor cells in the mature zebrafish retina." Advances in experimental medicine and biology 613, (0): 361-8. Details. Full text
* Publications are automatically pulled from based on a user-specific query. Results may include incorrect citations. See: Tutorial on improving PubMed results.
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