Department of Zoology

Katia Del Rio-Tsonis
Ph.D. University of Mexico, 1996
developmental biology, tissue regeneration
244 PSN

253G PSN



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Office Hours:
  Monday . . . .
  Tuesday . . . . 1:00 - 2:00
  Wednesday . .
  Thursday. . . . 1:00 - 2:00
  Friday. . . . . . Others by appt.

Biographical Information:

Katia Del Rio-Tsonis has concentrated her recent research efforts in the understanding of the cellular and molecular events that take place during tissue regeneration, more specifically in the process of lens regeneration and retina regeneration. Several animal models are used in her lab including the embryonic chick and amphibians such as newts and frogs.

Some adult salamanders have the remarkable ability of regenerating the entire lens and retina after removal. This is achieved by the dedifferentiation of the iris pigment epithelial cells (IPEC) and of the retinal pigmented epithelial cells (RPEC) respectively. These cells lose their pigments and transdifferentiate directly to either lens cells or retina cells. This transition from one adult cell type to another is unique and involves specific regulation at the gene level. In vivo, this ability for transdifferentiation and regeneration is restricted to some salamanders, but PEC from many other animals, including humans, do retain the capacity for transdifferentiation when isolated and cultured in vitro.The embryonic chick is able to regenerate its retina not only by transdifferentiation of RPEC, but also via the activation of stem cells present in the anterior region of the eye. Using both animal models, the focus is to determine the mechanism of transdifferentiation and regeneration by dissecting important molecules and signaling pathways involved.

The overall goal is to understand the molecular and cellular mechanisms involved in the process of regeneration from the terminally differentiated pigment epithelial cells or retinal stem cells to the newly formed lens and retina. This will provide important information for the understanding of the development of such tissues and also could provide possible tools for future therapies for the already existing diseases of the eye that affect the lens (cataracts) and the retina (retina degenerative diseases such as Cone-Rod Dystrophy, Best Disease, Stargardt Disease, Juvenile Retinoschisis and Leber Congenital Amaurosis).

Courses Taught:

  1. Patterns in Development (ZOO 202 - now ZOO 361)
  2. Cancer Biology (ZOO 449/549)
  3. Graduate Seminar (ZOO 710)

Recent Publications:

  1. Haynes, T., Gutierrez, C., Aycinena, J. C., Tsonis, P.A and Del Rio-Tsonis, K. BMP signaling mediates stem/progenitor cell induced neural retina regeneration. PNAS 104(51):20380-5, 2007.

  2. Spence JR, Madhavan M, Aycinena JC and Del Rio-Tsonis, K. FGF-Hedgehog Interdependence During Retina Regeneration. Dev. Dyn. 236:1161–1174, 2007.

  3. Madhavan M, Haynes, T, Call MK, Minich CM, Smith TH, Tsonis PA and Del Rio-Tsonis K. The role of Pax-6 in lens regeneration. PNAS 103(40):14848-53, 2006.

  4. Grogg, M.W, Call, K.C, Okamoto, M. Vergara, M.N., Del Rio-Tsonis, K. and Tsonis, P.A.BMP inhibition-driven regulation of six-3 underlies induction of newt lens regeneration. Nature 438(7069):858-862, 2005.

  5. Spence, J.R., Madhavan, M., Ewing, J.D., Jones, D. K., Lehman, B. M., Del Rio-Tsonis, K. The hedgehog pathway is a modulator of retina regeneration. Development 131(18): 4607-4621, 2004.