The molecular basis of daily and seasonal migration behaviour in the copepod Calanus finmarchicus in the face of climate change

面对气候变化，桡足类Calanus finmarchicus每日和季节性迁徙行为的分子基础

• 批准号: 2889087
• 金额: --
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2889087
• 关键词: molecular; basis; daily; seasonal; migration

Climate-change-induced increases in oceanic temperatures are causing poleward distribution range shifts in many temperate marine organisms. These shifts have far-reaching effects on marine food webs and oceanic carbon fluxes. Zooplankton are a central component of oceanic ecosystems, where they capture primary carbon fixed by phytoplankton and provide the major carbon source to higher trophic levels, including commercially important fish stocks. The cosmopolitan and lipid-rich copepod Calanus finmarchicus dominates zooplankton biomass in the North Atlantic and has emerged as a powerful model organism for understanding the biogeochemical processes in oceanic carbon cycling.Calanus displays two behaviours that are crucial for its role in the oceanic food web and carbon pump. First, diel vertical migration (DVM), which is a circadian behaviour whereby the animals dive to depth during the day and migrate to the surface to feed at night. This behaviour is a predator avoidance response and is driven primarily by light. Second, long resting stage (diapause), which is a crucial part of the life cycle of Calanus whereby juveniles in their last pre-adult copepodid stage in late spring migrate from their surface feeding grounds down to deeper epipelagic waters (~400-1000m) where they remain inactive for 7-8 months until January. The factors governing timing of diapause entry and exit remain unclear, but are suspected to include daylength, temperature and lipid reserves.Both DVM and diapause structure populations in space and time and both behaviours are sensitive to changes in environmental cues. Climate change is facilitating range expansions into higher latitudes where the cues (light, temperature) governing these behaviours are likely to differ from those at lower latitudes. Therefore, the capacity of individuals and populations to respond to these phenological shifts via phenotypic plasticity and/or adaptation will be a crucial factor in affecting realised range shifts, biomass flux and broader biogeochemical processes in the North Atlantic.A major hindrance in predicting population responses to phenological shifts is a lack of insight into the physiological and molecular processes affecting behavioural variability at the individual level. DVM timing, speed and depth vary measurably among individuals and show some correlation with among-individual variability in photo-responsiveness (unpublished ongoing work in KSL's group) and metabolic factors such as respiration rates and lipid reserves. Similarly, individuals vary in their timing of diapause entry, though diapause exit is often remarkably synchronised. Very little is known about the molecular genetic basis of this among-individual variation, of the physiological basis of behavioural synchronicity, and how adaptive genetic diversity among Calanus populations is structured in space and time.This project will examine the molecular genetic variation associated with variation in DVM and diapause behaviour and environmental factors likely to drive behavioural synchronicity. The principal aims are twofold: First, to examine the links between gene expression, behavioural phenotypic plasticity and environmental factors hypothesised to trigger and synchronise DVM and diapause. Second, to examine genetic diversity and genetic structure among populations from different latitudes from nearshore coastal to open ocean environments. We hypothesise that, first, environmental triggers of DVM/diapause cause changes in expression at key genes involved in biological rhythms consistent with phenotypic plasticity, and, second, that these genes show allele-frequency differences among populations from different latitudes, consistent with an adaptive evolutionary response to range shifts.

气候变化引起的海洋温度升高正在导致许多温带海洋生物的极端分布范围变化。这些转变对海洋食品网和海洋碳通量具有深远的影响。浮游动物是海洋生态系统的核心组成部分，在那里它们捕获了由浮游植物固定的原代碳，并将主要的碳源提供到较高的营养水平，包括商业上重要的鱼类种群。国际大都会和富含脂质的Copepod Calanus Finmarchicus在北大西洋中占主导地位，并已成为一种强大的模型有机体，旨在理解海洋碳循环中的生物地球化学过程。CALANUS表现出两种在海洋食品网络和Curbon Pump和Curbon Pump和Curbon Pump和Curbon Pump和Curbon Pump和Curbon Pump and Curbon Pump和Curbon Pump and Curbon Pump and Curbon Pump and Curbon Pump and Curbon Pump and Curbon pump。首先，Diel垂直迁移（DVM），这是一种昼夜节律的行为，这些动物白天会潜入深度，并在夜间迁移到表面。这种行为是捕食者的回应，主要由光驱动。其次，长期休息阶段（二二二），这是卡拉努斯生命周期的关键部分，在春末，少年在他们的最后一个成年前的共同体阶段从其表面喂养地面迁移到更深的表皮水域（〜400-1000m），直到1月至1月，他们一直保持不足。控制诊断时间和退出时间的因素尚不清楚，但怀疑包括日长度，温度和脂质储量。dvm和时空中的dvm和隔离结构种群，这两种行为对环境提示的变化敏感。气候变化正在促进范围扩展到更高的纬度，在这些纬度中，管理这些行为的提示（光，温度）可能与较低纬度的行为有所不同。因此，个人和人群通过表型可塑性和/或适应对这些物候转移做出反应的能力将是影响实现的范围转移，生物量通量和更广泛的生物地球化学过程的关键因素。在预测对现象学级别的人群对现象的影响方面，主要的人口响应是一种洞察力和分类。 DVM的时间，速度和深度在个体之间有所不同，并且与光响应性（KSL组未发表的工作）和呼吸率和脂质储量等代谢因素的相关性有所不同。同样，个体在诊断时间的时间内也有所不同，尽管隔离出口通常被显着同步。关于这种个体变异的分子遗传基础，行为同步的生理基础以及对氏氏氏氏氏菌种群之间的自适应遗传多样性的结构，该项目将研究与DVM变异的分子遗传变异以及对行为同步性的差异可能会促进行为和环境因素。主要目的是双重的：首先，检查基因表达，行为表型可塑性与所假设的环境因素之间的联系，以触发和同步DVM和抑郁。其次，检查来自近岸沿海到开放海洋环境的不同纬度人群中的遗传多样性和遗传结构。我们假设，首先，DVM/Diapause的环境触发因素会导致与表型可塑性一致的生物节奏的关键基因表达变化，其次，这些基因在不同纬度的人群中表现出与范围移动范围移动的不同纬度人群之间的等位基因频率差异。