Genetic mechanisms underlying variation in the visual systems of the freshwater fishes in the genus Etheostoma

Abstract

Event Abstract Back to Event Genetic mechanisms underlying variation in the visual systems of the freshwater fishes in the genus Etheostoma Jennifer Gumm1*, Karen Carleton2 and Tamra Mendelson1 1 University of Maryland, Baltimore County, United States 2 University of Maryland, United States Variation in visual systems may lead to differences in visually mediated behaviors. In fishes, visual sensitivity has been correlated with behaviors such as female mate preferences. In freshwater fishes known as darters (genus Etheostoma), males express elaborate breeding coloration and females express mate preferences based on male coloration. Darters are dichromatic with photoreceptors sensitive to medium (518 - 531 nm) and long (599 - 613 nm) wavelengths of light. The measured wavelength of peak sensitivity in both of these photoreceptor types varies both among and within species. Visual sensitivity is determined predominantly by visual pigments composed of an opsin protein bound to a light-sensitive chromophore. Proximately, at least two molecular mechanisms underlie variation in visual sensitivity: 1) Structural changes, wherein sequence differences in the coding regions of opsin proteins alter the types and spectral characteristics of the visual pigment and 2) differential gene expression, which alters spectral sensitivity through regulation of opsin genes. We tested whether variation in darter visual sensitivity is due to differences in gene sequence, gene expression, or both. Sequencing the opsin genes in 18 species of darters, we found variation in known vertebrate spectral tuning sites both among and within species. Structural (i.e. amino acid) changes in the medium wavelength sensitive opsin gene appear to contribute most to the measured variation in visual sensitivity. Additionally, we are using qPCR methods to assess relative levels of gene expression of the medium and long wavelength sensitive opsin genes. Preliminary data further suggests that regulatory changes also contribute to the diversity of visual systems in darters. By linking visual physiology and genetic mechanisms within and among species, our results will help elucidate the relative contributions of structural and regulatory changes during the diversification of visual systems. Keywords: evolution of visual systems, freshwater fishes, Genetic mechanisms, Opsin, Visual Systems Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for Participant Symposium) Topic: Sensory: Vision Citation: Gumm J, Carleton K and Mendelson T (2012). Genetic mechanisms underlying variation in the visual systems of the freshwater fishes in the genus Etheostoma. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00427 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 May 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Jennifer Gumm, University of Maryland, Baltimore County, Baltimore, MD, United States, jgumm@umbc.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jennifer Gumm Karen Carleton Tamra Mendelson Google Jennifer Gumm Karen Carleton Tamra Mendelson Google Scholar Jennifer Gumm Karen Carleton Tamra Mendelson PubMed Jennifer Gumm Karen Carleton Tamra Mendelson Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.