The formation of the light-sensing compartment of cone photoreceptors coincides with a transcriptional switch.

ABSTRACT: High-resolution daylight vision is mediated by cone photoreceptors. The molecular program responsible for the formation of their light sensor, the outer segment, is not well understood. We correlated daily changes in ultrastructure and gene expression in postmitotic mouse cones, between birth and eye opening, using serial block-face electron microscopy (EM) and RNA sequencing. Outer segments appeared rapidly at postnatal day six and their appearance coincided with a switch in gene expression. The switch affected over 14% of all expressed genes. Genes that switched off were rich in transcription factors and neurogenic genes. Those that switched on contained genes relevant for cone function. Chromatin rearrangements in enhancer regions occurred before the switch was completed, but not after.

SUBMITTER: Daum JM 

PROVIDER: S-EPMC5685475 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature