Why are there so many opsin genes in fish?

为什么鱼类中有如此多的视蛋白基因？

• 批准号: 262783-2013
• 负责人: Taylor, John
• 金额: $ 1.6万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=594765
• 关键词: Why; there; so; many; opsin

Over the next five years there are two significant questions I aim to answer as part of my long-term study of gene duplication and divergence: 1) Why do fish have so many opsins genes? 2) Is opsin mRNA transcript abundance a good proxy for opsin protein abundance? By day, most humans are trichromatic. Different light-sensitive cone cells in our retinas express short, medium, or long wavelength-sensitive opsin genes. This repertoire, while larger than that of most mammals, pales in comparison to fish. For example, guppies have nine and zebrafish have eight different cone cell opsins. Not only do fish have lots of opsin genes, they have an enormous diversity. Why? The data we will collect from flatfish, guppies, stickleback and zebrafish will allow us to test four hypotheses: i) A large opsin gene 'toolkit' improves the ability of fish to match their vision to variation in their spectral environment. ii) 'Visual opsins' have non-ocular roles, specifically in the skin, that are better served by a large opsin repertoire. iii) There is selection for regional specialization in the retina (i.e., different opsins expressed in different parts of the retina). iv. Opsin duplication and divergence enhances wavelength discrimination and/or wavelength sensitivity. Three of these hypotheses will be tested by measuring opsin transcript (mRNA) abundance. However, recent experiments suggest that the differential expression of mRNA captures at most 40% of the variation of protein expression. I will use two model species (zebrafish and stickleback), opsin genes, and two new technologies, digital droplet PCR and multi reaction monitoring-based mass spectrophotometry or 'MRM MS' to answer my second question. This research will be of great importance to an enormous number of scientists who quantify gene transcript abundance (e.g., using qPCR) under the assumption that these data are correlated with gene function, that is, with protein abundance.

在接下来的五年中，我要回答两个重要的问题，这是我对基因重复和分歧的长期研究的一部分：1）为什么鱼类有这么多的Opsins基因？ 2）OPSIN mRNA转录物丰度是否是Opsin蛋白丰度的良好代理？白天，大多数人是三色的。视网膜中的不同光敏锥细胞表达短，培养基或长波长敏感的Opsin基因。与大多数哺乳动物相比，这种曲目虽然大于大多数哺乳动物的曲目。例如，孔雀鱼具有九种和斑马鱼具有八个不同的锥细胞蛋白。鱼类不仅具有许多蛋白酶基因，而且具有巨大的多样性。为什么？我们将从Flatfish，Guppies，Stickleback和斑马鱼中收集的数据将使我们能够检验四个假设：i）一个大的Opsin基因“工具包”提高了鱼类与光谱环境中的视力相匹配的能力。 ii）“视觉动作蛋白”具有非眼作用，特别是在皮肤中，可以通过大型Opsin曲目更好地服务。 iii）在视网膜中选择了区域专业化（即，在视网膜的不同部分表达的不同OPSIN）。 iv。 Opsin重复和分歧增强了波长歧视和/或波长灵敏度。这些假设中的三个将通过测量Opsin转录（mRNA）丰度来测试。然而，最近的实验表明，mRNA的差异表达在蛋白质表达变化的最多40％。我将使用两个模型物种（斑马鱼和粘性基因），Opsin基因以及两种新技术，即数字液滴PCR和基于多反应监测的质量分光光度法或“ MRM MS”，以回答我的第二个问题。这项研究对于量化基因转录丰度（例如，使用qPCR）的大量科学家将非常重要，假设这些数据与基因功能相关，即与蛋白质丰度相关。