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The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. Common disease of the lens include cataracts, which cause opacity, or cloudiness, in the lens. Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world. Today, cataracts affect more than 22 million Americans age 40 and older. And as the U.S. population ages, it is projected to affect ~39 million people in the USA in 2030 (NEI statistics www.nei.nih.gov/eyedata/cataract#3, cited 2/9/15). So studying lens regeneration becomes important. Notophthalmus viridescens (newts) is a salamander which has marvelous capability to regenerate it’s organs, like heart, brain, lungs, limbs, tail, spinal cord, and lens. Lens regeneration in newts occurs by transdifferentiation, a switch of cell fate, where a fully differentiated somatic tissue reprograms and becomes a different one. And it always occurs exclusively from the dorsal aspect of the iris pigment epithelium (IPE), and never from the ventral part. The fact that the same type of cells-differentiated from same stem cell lineage-and belonging to the same tissue, has different regenerative capabilities is intriguing. Previously our lab using transcriptome analysis quantitatively compared gene expression between the dorsal and ventral samples. Very interesting patterns were obtained. Tbx5 was found over-expressed in the dorsal (>32 times) and Vax2 was over-expressed in the ventral iris (>32 times). Tbx5 and Vax2 are transcriptional factors known to be dorsal axis and ventral axis determinants during eye embryogenesis respectively. Objective of my research is to investigate the role of tbx-5, and vax-2 in lens induction.
Panagiotis A Tsonis
Primary Advisor's Department
Stander Symposium poster
Mehta, Abijeet S., "Towards Induction of Lens Regeneration" (2016). Stander Symposium Posters. 807.