Sanogo Yibayiri O, Hankison Shala, Band Mark, Obregon Alexandra, Bell Alison M
University of Illinois at Urbana Champaign, Urbana, Ill. 61801, USA.
Brain Behav Evol. 2011;77(4):270-85. doi: 10.1159/000328221. Epub 2011 Jun 16.
Predation pressure represents a strong selective force that influences the development and evolution of living organisms. An increasing number of studies have shown that both environmental and social factors, including exposure to predators, substantially shape the structure and function of the brain. However, our knowledge about the molecular mechanisms underlying the response of the brain to environmental stimuli is limited. In this study, we used whole-genome comparative oligonucleotide microarrays to investigate the brain transcriptomic response to cues of a predator in the threespine stickleback, Gasterosteus aculeatus. We found that repeated exposure to olfactory, visual and tactile cues of a predator (rainbow trout, Oncorrhynchus mykiss) for 6 days resulted in subtle but significant transcriptomic changes in the brain of sticklebacks. Gene functional analysis and gene ontology enrichment revealed that the majority of the transcripts differentially expressed between the fish exposed to cues of a predator and the control group were related to antigen processing and presentation involving the major histocompatibility complex, transmission of synaptic signals, brain metabolic processes, gene regulation and visual perception. The top four identified pathways were synaptic long-term depression, RAN signaling, relaxin signaling and phototransduction. Our study demonstrates that exposure of sticklebacks to cues of a predator results in the activation of a wide range of biological and molecular processes and lays the foundation for future investigations on the molecular factors that modulate the function and evolution of the brain in response to stressors.
捕食压力是一种强大的选择力，影响着生物的发育和进化。越来越多的研究表明，包括接触捕食者在内的环境和社会因素，极大地塑造了大脑的结构和功能。然而，我们对大脑对环境刺激作出反应的分子机制的了解有限。在本研究中，我们使用全基因组比较寡核苷酸微阵列来研究三刺鱼（Gasterosteus aculeatus）大脑对捕食者线索的转录组反应。我们发现，三刺鱼反复暴露于捕食者（虹鳟，Oncorrhynchus mykiss）的嗅觉、视觉和触觉线索6天，会导致其大脑发生细微但显著的转录组变化。基因功能分析和基因本体富集显示，暴露于捕食者线索的鱼与对照组之间差异表达的大多数转录本与涉及主要组织相容性复合体的抗原加工和呈递、突触信号传递、大脑代谢过程、基因调控和视觉感知有关。确定的前四条通路是突触长期抑制、RAN信号传导、松弛素信号传导和光转导。我们的研究表明，三刺鱼暴露于捕食者线索会导致多种生物和分子过程的激活，并为未来研究调节大脑功能和进化以应对应激源的分子因素奠定了基础。
