Detection of mRNA Encoding Organic Anion Transporters in Zebrafish Eyes

Abstract

The solute carrier 22 (slc22) family is a group of transmembrane proteins that specialize in the transport of organic ions. A sub‐category of slc22 consists of organic anion transporters (OAT) that transport cyclic nucleotides such as cyclic adenosine monophosphate (cAMP). In the process of light to dark adaptation of fish eyes, cAMP is hypothesized to be a regulatory signal between the photoreceptors and retinal pigment epithelium (RPE) that drives pigment granule aggregation in the latter. We hypothesize that cAMP is exported from the photoreceptors into the sub‐retinal space, and one of the slc22 OAT proteins imports cAMP into the RPE. To test this hypothesis, reverse transcription polymerase chain reaction (RT‐PCR) was used to test for the presence of mRNA encoding seven different OAT proteins (1, 2a, 2b, 2c, 2d, 2e and 3) in whole eyes from zebrafish. Messenger RNA encoding each of the OAT proteins was detected, corroborating results of earlier studies. Experiments are underway to test which of the OAT genes are expressed in isolated RPE. Identification of the OAT proteins in RPE is an important step in illuminating a novel signaling pathway.Support or Funding InformationThis project was supported by Texas State University in the form of an undergraduate research fellowship to MCR and funds from the Office of the Provost awarded to DMG in recognition of her service as Presidential Fellow.