Transgenic Reporter Analysis of Thyroid Hormone and Retinoic Acid Signaling in Zebrafish Retina
Faculty Mentor Information
Dr. Deborah Stenkamp, University of Idaho
Presentation Date
7-16-2026
Abstract
Vertebrate vision is dependent on cones expressing distinct types of opsins. Work from our lab and others has shown that thyroid hormone (TH) regulates cone opsin gene expression in zebrafish. However, the developmental timing, cone-type specificity, and TH responsiveness remain poorly resolved. To map thyroid hormone response element (TRE)-mediated activity across retinal development and determine how TH exposure alters the proportion of cones exhibiting TRE reporter activity, we used a 6xTRE:GFP zebrafish reporter line. Larval, juvenile, and adult zebrafish were treated with TH or vehicle controls, and TRE reporter activity was quantified across cone subtypes. TH robustly increased TRE-mediated reporter activity throughout development. Within the retina, expression was uniformly distributed in larvae, enriched peripherally and near the optic nerve in juveniles, and predominantly centralized in adults. These findings demonstrate sustained, cone-enriched sensitivity to TH throughout retinal development. As an extension of this work, we are investigating potential crosstalk between TH and retinoic acid (RA) signaling using the RARE:YFP reporter line. This ongoing study examines whether TH treatment alters the level or distribution of RA signaling activity in the developing retina or affects reporter activity, thus providing insight into how these conserved pathways among vertebrates may interact during cone photoreceptor development.
Transgenic Reporter Analysis of Thyroid Hormone and Retinoic Acid Signaling in Zebrafish Retina
Vertebrate vision is dependent on cones expressing distinct types of opsins. Work from our lab and others has shown that thyroid hormone (TH) regulates cone opsin gene expression in zebrafish. However, the developmental timing, cone-type specificity, and TH responsiveness remain poorly resolved. To map thyroid hormone response element (TRE)-mediated activity across retinal development and determine how TH exposure alters the proportion of cones exhibiting TRE reporter activity, we used a 6xTRE:GFP zebrafish reporter line. Larval, juvenile, and adult zebrafish were treated with TH or vehicle controls, and TRE reporter activity was quantified across cone subtypes. TH robustly increased TRE-mediated reporter activity throughout development. Within the retina, expression was uniformly distributed in larvae, enriched peripherally and near the optic nerve in juveniles, and predominantly centralized in adults. These findings demonstrate sustained, cone-enriched sensitivity to TH throughout retinal development. As an extension of this work, we are investigating potential crosstalk between TH and retinoic acid (RA) signaling using the RARE:YFP reporter line. This ongoing study examines whether TH treatment alters the level or distribution of RA signaling activity in the developing retina or affects reporter activity, thus providing insight into how these conserved pathways among vertebrates may interact during cone photoreceptor development.