Two Opsin 3-Related Proteins in the Chicken Retina and Brain: A TMT-Type Opsin 3 Is a Blue-Light Sensor in Retinal Horizontal Cells, Hypothalamus, and CerebellumReport as inadecuate




Two Opsin 3-Related Proteins in the Chicken Retina and Brain: A TMT-Type Opsin 3 Is a Blue-Light Sensor in Retinal Horizontal Cells, Hypothalamus, and Cerebellum - Download this document for free, or read online. Document in PDF available to download.

Opsin family genes encode G protein-coupled seven-transmembrane proteins that bind a retinaldehyde chromophore in photoreception. Here, we sought potential as yet undescribed avian retinal photoreceptors, focusing on Opsin 3 homologs in the chicken. We found two Opsin 3-related genes in the chicken genome: one corresponding to encephalopsin-panopsin Opn3 in mammals, and the other belonging to the teleost multiple tissue opsin TMT 2 group. Bioluminescence imaging and G protein activation assays demonstrated that the chicken TMT opsin cTMT functions as a blue light sensor when forced-expressed in mammalian cultured cells. We did not detect evidence of light sensitivity for the chicken Opn3 cOpn3. In situ hybridization demonstrated expression of cTMT in subsets of differentiating cells in the inner retina and, as development progressed, predominant localization to retinal horizontal cells HCs. Immunohistochemistry IHC revealed cTMT in HCs as well as in small numbers of cells in the ganglion and inner nuclear layers of the post-hatch chicken retina. In contrast, cOpn3-IR cells were found in distinct subsets of cells in the inner nuclear layer. cTMT-IR cells were also found in subsets of cells in the hypothalamus. Finally, we found differential distribution of cOpn3 and cTMT proteins in specific cells of the cerebellum. The present results suggest that a novel TMT-type opsin 3 may function as a photoreceptor in the chicken retina and brain.



Author: Mutsuko Kato, Takashi Sugiyama, Kazumi Sakai, Takahiro Yamashita, Hirofumi Fujita, Keita Sato, Sayuri Tomonari, Yoshinori Shichid

Source: http://plos.srce.hr/



DOWNLOAD PDF




Related documents