I see / smell / touch / hear and therefore I am: sex differences in perception alter survival and reproduction

我们繁殖得越多，寿命就越短。这一严酷的格言得到了数十年来从包括人类在内的许多不同动物身上收集的证据的支持。雌性对繁殖率提高的影响特别敏感，在实验室用昆虫进行的测试中，改变繁殖率可以使雌性的寿命缩短一半，甚至可以逆转哪种性别的寿命最长。尽管有了这些研究，我们对这些戏剧性的影响是如何发生的细节却出奇地缺乏了解。部分原因是许多实验室研究是在相对同质的环境中进行的，在这种环境中，一生中暴露于同性或异性的潜在混淆效应的可能性最小化，甚至不存在。然而，越来越明显的是，社会和性环境的影响会对衰老产生巨大影响。因此，许多旨在确定衰老途径的研究都缺少对两性寿命影响的丰富来源。与此同时，一个新的研究机构正在展示一些真正令人惊讶的东西：感知本身对寿命的作用。例如，仅仅是对同性或异性个体的感知，就可以以完全模仿实际接触的方式对生存和繁殖产生重大影响。在食物的气味与实际食用食物的效果之间也观察到了类似的效果！我们建议使用功能强大的果蝇模型系统，调查的重要性和作用的感知影响的社会和性环境的寿命，衰老和繁殖在两性。我们也想展示这些效应是如何与营养感应基因的效应联系在一起的，而这些基因本身对寿命的影响也有很好的记录。通过测量不同性别的焦点个体暴露于以下物质对每种性别的生存、衰老和生殖成功的影响：（i）同性、异性和两性个体，（ii）不同年龄的社会和性群体，（iii）直接接触与非直接接触，（iv）感觉输入受阻（嗅觉、听觉、触觉），（v）繁殖受阻（不育/可育），（vi）“不育”，即存在死/活个体。此外，我们将测试候选基因的影响，这些基因在以前的研究中被强调为重要的。通过测量1中的操作对感知吃了多少和吃了什么的基因表达的影响。我们已经知道，这些基因在男性和女性中表现出非常不同的表达模式，并且当它们开始繁殖时，这种表达模式会发生变化。通过测量1中所采用的操作如何改变这些基因在每种性别中的活性，我们将能够提供对预期繁殖水平的感知、营养感测的激活和最终寿命之间的直接联系。这将通过对候选基因的直接测试来证实，这些候选基因被强调为介导这些效应的关键。这项工作旨在为为什么生殖缩短寿命和加速衰老提供重要的测试。它还将强调感知效应在决定寿命方面的重要性，并展示这可能是如何工作的。这项研究预计将在我们对每个性别的寿命和衰老的基本理解方面取得重大进展，并将与人类研究直接相关，因为我们将研究的许多途径都与我们自己共享。

The more we reproduce, the shorter we live. This stark maxim is supported by evidence gathered across decades from many different animals including humans. Females are particularly sensitive to the effects of elevated reproduction and in laboratory tests using insects, varying the amount of reproduction can decrease female length of life by up to a half, and even reverse which sex lives longest.Despite all this study, we have a surprising lack of knowledge about the details of how these dramatic effects occur. Partly this is because many laboratory studies are done in a relatively homogenous environment in which exposure to potentially confounding effects of the same or opposite sex throughout life are minimised or even absent. It is becoming increasingly clear, however, that effects of the social and sexual environment can have dramatic effects on ageing. Hence a rich source of effects on the lifespan of each sex is missing from many studies that aim to identify ageing pathways.Coupled with this, a new body of research is showing something really surprising: the role of perception itself on lifespan. For instance, the mere perception of same or opposite sex individuals, can have significant effects on survival and reproduction in a way that completely mimics actual exposure. Similar effects are observed in relation to the effect of the smell of food, versus actually eating it!We propose to use the powerful fruitfly model system to investigate the importance and role of the perceptual effects of the social and sexual environment on lifespan, ageing and reproduction in both sexes. We also aim to show how these effects are linked to those of nutrient sensing genes that themselves have well-documented effects on lifespan.We will do this in two parts:1. By measuring the effect on the survival, ageing and reproductive success of each sex of varying the exposure of focal individuals of both sexes to: (i) same, opposite and both sex individuals, (ii) social and sexual groups of varying age, (iii) direct versus no direct contacts, (iv) blocked sensory inputs (smell, sound vision, touch), (v) blocked reproduction (sterile / fertile), (vi) 'danger', i.e. the presence of dead / live individuals. In addition, we will test the effects of candidate genes highlighted as important from previous research.2. By measuring the effect of the manipulations in 1 on the expression of genes that sense how much and what has been eaten. We already know that such genes show a very different pattern of expression in males versus females and that this is changed when they initiate reproduction. By measuring how the manipulations employed in 1 change the activity of these genes in each sex we will be able to provide a direct link between perception of the expected level of reproduction, activation of nutrient sensing and ultimate lifespan. This will be confirmed by direct tests with candidate genes, that have been highlighted as key in mediating these effectsThe work aims to provide important tests of why reproduction shortens life and speeds up ageing. It will also highlight the emerging importance of perceptual effects in determining lifespan and show how this might work. The research is expected to result in a major advance in our fundamental understanding of lifespan and ageing in each sex and will have direct relevance to studies on humans, given that many of the pathways we will be studying are shared with ourselves.