Nuclear Hormone Signaling and Regulation of Cone Photoreceptor Gene Expression in the Zebrafish
Additional Funding Sources
This project is supported by a 2019-2020 STEM Undergraduate Research Grant from the Higher Education Research Council.
Abstract
Vertebrate color vision requires spectrally selective opsin-based pigments that are expressed in separate cone photoreceptor populations. The regulation of cone opsin expression is poorly understood. The common model used to describe regulation of tandemly-replicated opsin genes in humans suggests that locus control regions (LCR) interact with each of the tandemly replicated opsin genes at random. However, it has been found that in human retina there are topographic gradients in red: green cone ratios which suggests that a trans regulatory mechanism is involved in their expression. Publications from the Stenkamp lab have shown that thyroid hormone (TH) is involved in the endogenous regulation of LWS (long-wavelength sensitive, red-sensing) opsin expression in zebrafish larvae and juveniles; more recently, research was conducted on adult zebrafish with TH treatments showing similar results. With this project, further research was done to better understand the regulation and expression of LWS1 and LWS2 cone opsin in response to TH in larvae and adult zebrafish. This included determining the effects of TH on a transgenic reporter line that has had elements deleted from the regulatory region of the LWS array and further characterizing the effect of TH on adult zebrafish cones.
Nuclear Hormone Signaling and Regulation of Cone Photoreceptor Gene Expression in the Zebrafish
Vertebrate color vision requires spectrally selective opsin-based pigments that are expressed in separate cone photoreceptor populations. The regulation of cone opsin expression is poorly understood. The common model used to describe regulation of tandemly-replicated opsin genes in humans suggests that locus control regions (LCR) interact with each of the tandemly replicated opsin genes at random. However, it has been found that in human retina there are topographic gradients in red: green cone ratios which suggests that a trans regulatory mechanism is involved in their expression. Publications from the Stenkamp lab have shown that thyroid hormone (TH) is involved in the endogenous regulation of LWS (long-wavelength sensitive, red-sensing) opsin expression in zebrafish larvae and juveniles; more recently, research was conducted on adult zebrafish with TH treatments showing similar results. With this project, further research was done to better understand the regulation and expression of LWS1 and LWS2 cone opsin in response to TH in larvae and adult zebrafish. This included determining the effects of TH on a transgenic reporter line that has had elements deleted from the regulatory region of the LWS array and further characterizing the effect of TH on adult zebrafish cones.