Transcriptional control of cone photoreceptor diversity by a thyroid hormone receptor

Purpose: To define the cone photoreceptor diversity and underlying transcriptional controls in mouse retina Methods: Individual retinal cone cells were isolated by micro-manipulator from dissociated pieces of superior/inferior retina from heterozygous (or homozygous) Thrb-b2Cre:Ai6 mice. Single cell libraries were constructed for RNA-seq analysis. Thrb-b2Cre;Rosa26-Sun1Gfp mice were used to isolate cone nuclei for ATAC-seq analysis. Thrb-HAB mice were used to identify TRb2 genomic binding sites using ChAP-seq analysis. Results: Developmental analyses of individual cones revealed a network of gradient genes. Many of these gradient genes are regulated by TRb2, a thyroid hormone receptor that has been associated with color visual impairment. Conclusions: The results suggest that TRb2 controls chromatin remodeling and transcriptional plasticity in the cone lineage to promote diversity. Derived a Thrb-b2Cre driver to isolate M and S opsin-enriched cones, which are distributed in counter-gradients over the mouse retina.