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

Elife. 2017 Nov 6;6:e31437. doi: 10.7554/eLife.31437.

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. We provide a resource comprised of correlated EM, RNAseq, and ATACseq data, showing that the growth of a key compartment of a postmitotic cell involves an extensive switch in gene expression and chromatin accessibility.

Keywords: RNA seq; computational biology; cones; mouse; neuroscience; retinal development; systems biology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation*
  • Gene Expression Profiling
  • Gene Expression Regulation*
  • Mice
  • Microscopy, Electron
  • Retina / growth & development*
  • Retinal Cone Photoreceptor Cells / physiology*
  • Retinal Cone Photoreceptor Cells / ultrastructure
  • Sequence Analysis, RNA
  • Transcription, Genetic*

Grant support

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.