权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Population genetics and fitness correlates of colour vision in wild sifaka lemurs

野生西法卡狐猴的种群遗传学和健康与色觉的相关性

基本信息

批准号：
NE/D007992/1
负责人：
Nicholas Mundy
金额：
$ 6.97万
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2006
资助国家：
英国
起止时间：
2006 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FD007992%2F1
关键词：
Population genetics fitness correlates colour

项目摘要

Although we generally accept that natural selection has shaped the appearance and behaviour of organisms, pin-pointing cases where a change in DNA sequence corresponds to an advantageous change in anatomy, physiology or behaviour remains a primary challenge for biology. One of the rare cases in which we can identify a clear link between DNA sequences and physiology / behaviour is the colour vision system of primates. Primates are the only placental mammals known to possess full (trichromatic) colour vision, and the distribution of this ability within the primate order is particularly interesting. Excluding the occasional colour-blind individuals, all humans, apes, and Old World monkeys have full colour vision. But in most New World monkeys and some lemurs, colour vision capacities of individuals can differ - all males and some females are red-green colour blind (dichromatic), but other females have full colour vision similar to that of humans. Moreover, colour blind individuals can differ in the range of colours that they discriminate. This creates an interesting situation in that individuals living in the same social group can see the world rather differently. But how does natural selection maintain this 'polymorphic' system? The possible advantages of having full colour vision are numerous: It may allow primates to find ripe reddish fruit against the background of green forest foliage or to spot young protein-rich leaves, which are often reddish, among the mature, less-nutritious, green leaves. However, there is speculation that red-green colour blindness might also confer an advantage. Studies in humans have demonstrated that colour-blind men are often better than those with full colour vision at detecting camouflaged patterns. Thus, red-green colour blind primates may have advantages in detecting camouflaged prey or predators, or in finding inconspicuous fruits. This study of wild Verreaux's sifaka lemurs will be the first to systematically examine links between evolutionary fitness (survival and reproduction) and colour vision status in a population of wild primates. This is an international collaboration with researchers at the sifaka field site at Beza-Mahafaly Special Reserve, Madagascar. The sifakas at this site have been studied since 1984 and all individuals over the age of one have been captured and sampled for genetic analysis. This provides an exceptional dataset with over two decades of records on the behavioural biology of individual sifaka. We will identify, through DNA sequencing of photopigment (opsin) genes, the colour vision status of 100 individuals. We will then examine whether colour vision status, alone or in combination with social factors (e.g. group size) and ecological factors (e.g. habitat quality), is a predictor of fitness. Specifically, we address three types of questions: 1. How are colour vision types distributed across the population? Do groups and/or breeding pairs associate in a non-random way with respect to colour vision status? Across the population, are some photopigment variants more common than others? 2. Does colour vision status predict an individual's fitness? Are individuals with full colour vision likely to survive longer and have more offspring than individuals who are red-green colour blind? Is this also influenced by social and/or ecological factors? 3. Is it beneficial to belong to a social group whose members have a variety of colour vision types? Is average lifespan and reproductive success greater for individuals in groups of mixed composition than for those in all colour blind groups (independent of individual colour vision status)? By examining how small genetic changes can influence individual fitness, we will better understand how natural selection can drive and maintain biodiversity in natural populations.

虽然我们普遍认为自然选择塑造了生物体的外观和行为，但确定DNA序列的变化对应于解剖学，生理学或行为的有利变化的情况仍然是生物学的主要挑战。我们可以确定DNA序列与生理/行为之间存在明确联系的罕见案例之一是灵长类动物的色觉系统。灵长类动物是唯一已知拥有完整（三色）色觉的胎盘哺乳动物，这种能力在灵长类动物中的分布特别有趣。除了偶尔的色盲个体，所有的人类、猿和旧大陆的猴子都有全色视觉。但在大多数新大陆猴和一些狐猴中，个体的色觉能力可能不同--所有雄性和一些雌性都是红绿色盲（二色性），但其他雌性具有与人类相似的全色觉。此外，色盲个体可以在他们所辨别的颜色范围内有所不同。这就造成了一种有趣的情况，即生活在同一社会群体中的个人可以以不同的方式看待世界。但自然选择是如何维持这种“多态”系统的呢？具有全色视觉的可能优势有很多：它可以让灵长类动物在绿色森林树叶的背景下找到成熟的红色水果，或者在成熟的、营养较少的绿色叶子中发现富含蛋白质的年轻叶子，这些叶子通常是红色的。然而，有人猜测红绿色盲也可能带来优势。对人类的研究表明，色盲男性往往比那些有全彩色视觉的人更好地检测出隐藏的图案。因此，红绿色盲灵长类动物可能在发现被捕食的猎物或捕食者，或发现不显眼的水果方面具有优势。这项对野生Verreaux的狐猴的研究将是第一个系统地研究野生灵长类动物种群中进化适应性（生存和繁殖）与色觉状态之间联系的研究。这是与马达加斯加Beza-Mahafaly特别保护区的sifaka现场研究人员的国际合作。自1984年以来一直在研究这个地点的狐猴，所有超过一岁的个体都被捕获并取样进行遗传分析。这提供了一个特殊的数据集，其中有超过二十年的关于个体狐猴行为生物学的记录。我们将通过对色素（视蛋白）基因进行DNA测序，确定100名个体的色觉状况。然后，我们将研究是否色觉状态，单独或与社会因素（如组大小）和生态因素（如栖息地质量）相结合，是健身的预测。具体来说，我们解决三种类型的问题：1。色觉类型如何在人群中分布？群体和/或繁殖对是否以非随机的方式与色觉状态相关？在整个人群中，某些色素变异比其他变异更常见吗？2.色觉状态能预测个体的健康状况吗？具有全色视觉的个体是否比红绿色盲的个体存活更长时间并拥有更多的后代？这是否也受到社会和/或生态因素的影响？3.属于一个成员具有多种色觉类型的社会群体是否有益？平均寿命和繁殖成功率更大的个人在群体的混合组成比那些在所有色盲群体（独立的个人色觉状态）？通过研究微小的遗传变化如何影响个体适应性，我们将更好地理解自然选择如何驱动和维持自然种群的生物多样性。