Bovine opsin gene expression exhibits a late fetal to adult regulatory switch.

Academic Article

Abstract

  • Rates of bovine photoreceptor gene transcription, as measured by nuclear run-on assays, exhibit gene-specific patterns of regulation. Here we investigate initiation and elongation in nuclear run-on assays with the use of sarkosyl to further understand the nature of these gene-specific elements. Opsin transcription, alone among several genes tested, proved sarkosyl-sensitive. This sensitivity is maximal in adult retinas, with inhibition first detected in mid-third trimester fetal retinas. Therefore, opsin transcription appears to involve different regulatory elements in adult and fetal retinas, implying a fetal to adult switch in the control of opsin gene expression. Although this regulatory switch is initially activated at a time when the fetal outer nuclear layer of the retina first achieves adult-like morphology, further maturation of opsin regulation takes place postpartum since levels of sarkosyl sensitivity are almost 5-fold greater in adult retinas compared to the 7.5 month fetus. We also show that the sarkosyl-induced reduction of opsin transcription is not due to prevention of de novo RNA polymerase II initiation in the run-on reaction, suggesting the detergent alters a positive-acting, postinitiation component of the transcriptional apparatus. Since levels of opsin transcription with sarkosyl are similar to those of the other visual transduction genes with or without sarkosyl, this detergent-sensitive transcriptional component appears to account for the singularly high, gene-specific rate of opsin transcription in retinal photoreceptor cells.
  • Authors

  • DesJardin, LE
  • Lockwood, Mary Katherine
  • Hauswirth, WW
  • Status

    Publication Date

  • April 15, 1995
  • Published In

    Keywords

  • Aging
  • Animals
  • Cattle
  • Embryo, Mammalian
  • Embryonic and Fetal Development
  • Female
  • Fetus
  • Gene Expression Regulation
  • Genes, Switch
  • Photoreceptor Cells
  • Retina
  • Rod Opsins
  • Sarcosine
  • Transcription, Genetic
  • Digital Object Identifier (doi)

    Pubmed Id

  • 7543158
  • Start Page

  • 728
  • End Page

  • 736
  • Volume

  • 40
  • Issue

  • 6