Effect of Genetic and Environmental Variation on Diversification Due to Sexual Selection

我们感兴趣的是确定孔雀鱼雌性择偶变异的分子遗传基础，孔雀鱼是性选择和自然选择研究的重要系统。 孔雀鱼雄性色彩鲜艳，而女性不表现出色彩，但确实表现出基于这些男性色彩模式的配偶选择。 孔雀鱼系统的优势之一是雌性在种群内和种群之间表现出择偶的强度和类型的变化。 例如，某些种群的雌性在选择配偶时比其他种群的雌性更喜欢橙子。 这种雌性配偶选择的变异是孔雀鱼成为研究雌性配偶选择进化的重要系统的主要原因之一，因为除非某个性状表现出变异，否则不可能研究该性状的进化。 我们关注的是视蛋白基因，因为视蛋白有助于调节视网膜的颜色敏感度。 例如，人类只有红色、绿色和蓝色视蛋白，当其中一种被破坏时，个体至少是部分“色盲”。“孔雀鱼有10种不同的视蛋白类型，是所有脊椎动物中最多的，我们假设个体之间这些视蛋白序列的差异，或者这些基因何时何地打开或关闭的差异，可能解释了雌性之间择偶的大部分差异。 我们正在从经历各种光照环境的自然种群中收集孔雀鱼，并在实验室中在不同的光照条件下饲养孔雀鱼，以测试遗传差异或视蛋白基因表达的变异是否与配偶选择相关。 雌性孔雀鱼在择偶上的差异也有可能是因为它们处理来自视网膜的感觉输入的方式不同，我们正在使用现代基因组技术来调查雌性孔雀鱼在看到有吸引力或没有吸引力的雄性孔雀鱼时大脑中表达的所有基因。 我们确定颜色配偶选择的遗传基础将是进化研究的一个重大进展，但也将使我们深入了解脊椎动物视觉系统的进化和发展。

We are interested in determining the molecular genetic basis for variation in female mate choice in guppies, an important system for studies of sexual and natural selection. Guppy males are brightly colored, while females do not exhibit coloration, but do exhibit mate choice based on these male coloration patterns. One of the strengths of the guppy system is that females exhibit variation within and between populations for the strength and type of mate choice. For example, females from some populations are much more attracted to orange coloration when choosing mates than are females from other populations. This variation in female mate choice is one of the main reasons why the guppy is such an important system for the study of the evolution of female mate choice, because it is not possible to study the evolution of a trait unless that trait shows variation. We are focusing on opsin genes, because opsins help tune the color sensitivity of the retina. For example, humans have only red, green and blue opsins, and when one of these is disrupted the individual is at least partially "colour blind." Guppies have 10 different opsin types, the most for any vertebrate, and we hypothesize that differences in the sequences of these opsins among individuals, or differences in when and where these genes are turned on or off, might explain much of the difference among females for mate choice. We are collecting guppies from natural populations experiencing various light environments, and also raising guppies in the lab under varying light conditions, to test whether genetic differences or variation in opsin gene expression correlates with mate choice. It is also possible that females differ in mate choice because they process sensory input from the retina in different ways, and we are using modern genomic techniques to survey all of the genes expressed in the brains of female guppies when they are shown attractive or non-attractive males. Our determination of the genetic basis of mate choice for color will be a major advance in the study of evolution, but will also give insight into the evolution and development of the vertebrate visual system.