Uncovering the functional basis of the reversal of the fecundity/longevity trade-off in a termite

揭示白蚁繁殖力/寿命权衡逆转的功能基础

• 批准号: 276411962
• 负责人: Professorin Dr. Judith Korb
• 金额: --
• 依托单位: Départment de Biologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/276411962?language=en
• 关键词: Uncovering; functional; basis; reversal; fecundity

Reversal of the fecundity/longevity trade-off evolved several times independently with sociality. This provides strong support for the hypothesis that sociality, fecundity and lifespan influence each other during evolution. Our molecular results from the first funding phase indicate convergent evolution at the pathway level. For all studied species, we identified caste-specific, age-related changes in the network along the TOR (target of rapamycin)/IIS (insulin/insulin-like growth factor1 signalling) - juvenile hormone (JH) axis that affects pathways linked to lifespan and fecundity (the TI-J-LiFe network for TOR/IIS-JH-Lifespan Fecundity). Yet details seem to differ between species. In addition, we found for termites a strong signal of age-related transposable element (TE) activity, which we did not detect in the social Hymenoptera. These ‘jumping genes’ have long been hypothesized to play a role in ageing in animals and recently a causal link has been demonstrated. During the second funding phase, we aim to analyse the identified mechanisms in more detail by performing functional experiments in a termite to reveal pathways and networks underlying ageing and the apparent reversal of the fecundity/longevity trade-off. By doing this in termites, we will study the oldest social insects and the largest lineage outside the Hymenoptera that evolved eusociality. We have three Objectives:In a common effort shared across all projects in Focus B ‘Regulators’, we will investigate in Objective 1 the role of protein availability for queen fecundity. In doing so, we will focus on the TOR part of the TI-J-LiFe network. We will test the hypothesis that additional protein increases the fecundity of queens. By undertaking a food-supplement experiment, we will analyse how queen and worker longevity are affected by additional protein sources. Based on results from the first funding phase, we will test in Objective 2 the hypothesis that a change in the regulation of FOXO by Akt in queens can account for an upregulation of IIS signalling without negative consequences on FOXO and its downstream pathways. Here we will concentrate on the IIS-JH-Vitellogenin part of the TI-J-LiFe network. Objective 3 will test the hypothesis that TE activity and caste-specific TE silencing mechanisms contribute to explain longevity differences between queens and workers and the reversal of the fecundity/longevity trade-off. Our studies we will offer insights into mechanisms of ageing and the reversal of the fecundity/longevity trade-off that will help to reveal molecular constraints and lineage specific idiosyncrasies.

生殖力/寿命权衡的抑制与社会性独立地进化了几次。这为社会性、繁殖力和寿命在进化过程中相互影响的假设提供了强有力的支持。我们的第一个资助阶段的分子结果表明在途径水平上的趋同进化。对于所有研究的物种，我们确定了种姓特定的，年龄相关的变化，在网络沿着TOR（雷帕霉素的目标）/IIS（胰岛素/胰岛素样生长因子1信号）-保幼激素（JH）轴，影响与寿命和生育力（TOR/IIS-JH-寿命生育力的TI-J-LiFe网络）。然而，细节似乎因物种而异。此外，我们发现白蚁的年龄相关的转座因子（TE）的活动，我们没有检测到在社会Hypltera的强烈信号。这些“跳跃基因”长期以来一直被假设在动物衰老中发挥作用，最近一个因果关系已经得到证实。在第二个资助阶段，我们的目标是通过在白蚁中进行功能实验来更详细地分析所确定的机制，以揭示衰老的潜在途径和网络以及生育力/寿命权衡的明显逆转。通过在白蚁中这样做，我们将研究最古老的社会性昆虫和最大的谱系以外的Hyattera进化真社会性。我们有三个目标：在焦点B“调节器”的所有项目中，我们将在目标1中研究蛋白质可用性对蜂王繁殖力的作用。在此过程中，我们将重点关注TI-J-LiFe网络的TOR部分。我们将测试的假设，额外的蛋白质增加了女王的繁殖力。通过进行食物补充实验，我们将分析女王和工人寿命如何受到额外蛋白质来源的影响。基于第一个资助阶段的结果，我们将在目标2中测试以下假设：皇后中Akt对FOXO调控的变化可以解释IIS信号转导的上调，而不会对FOXO及其下游通路产生负面影响。在这里，我们将集中在TI-J-LiFe网络的IIS-JH-卵黄蛋白原部分。目标3将测试的假设，TE活动和种姓特定的TE沉默机制有助于解释寿命差异之间的皇后和工人和逆转的生育力/寿命权衡。我们的研究，我们将提供深入了解衰老的机制和生殖力/寿命权衡的逆转，这将有助于揭示分子的限制和谱系特异性特质。