Synergistic pheromone antagonists perturb olfactory balance and reduce reproduction of invasive sea lamprey. Scott et al.

Summary: Sex pheromones impart maximal attraction when their components are present at optimal ratios that confer balanced olfactory inputs in potential mates. Altering ratios or adding pheromone analogs to optimal mixtures may disrupt balanced olfactory antagonism and result in reduced attraction, however tests in natural populations are lacking. We tested this hypothesis in sea lamprey (Petromyzon marinus), a fish whose male sex pheromone attracts females when two critical components, 3-keto petromyzonol sulfate (3kPZS) and petromyzonol sulfate (PZS), are present at certain ratios. Here, we report a pheromone analog, petromyzonol tetrasulfate (3sPZS), reduced female attraction to 3kPZS but not to PZS. 3sPZS mixed with additional PZS synergistically disrupted female attraction to the male pheromone and reduced spawning by 97% in a high-density population. Our results provide evidence of balanced olfactory antagonism in a vertebrate and establish a tactic to disrupt spawning of sea lamprey, a destructive invader of the Laurentian Great Lakes.

摘要：性信息素的各组分若处于最优比例，可向潜在配偶传递平衡的嗅觉输入信号，从而发挥最大吸引效能。改变组分比例或向最优混合液中添加信息素类似物，可能破坏平衡的嗅觉拮抗作用，导致吸引效果减弱，但目前尚缺乏针对自然种群的相关验证。本研究以海七鳃鳗（Petromyzon marinus）为研究对象验证该假说：该鱼类的雄性性信息素需在两种关键组分——3-酮基七鳃鳗醇硫酸盐（3-keto petromyzonol sulfate, 3kPZS）与七鳃鳗醇硫酸盐（petromyzonol sulfate, PZS）——处于特定比例时，方可对雌性产生吸引作用。本研究发现一种信息素类似物——四硫酸七鳃鳗醇（petromyzonol tetrasulfate, 3sPZS）——可降低雌性对3kPZS的趋性，但对PZS无显著影响。当3sPZS与额外添加的PZS混合后，可协同破坏雌性对雄性信息素的趋性，并在高密度种群中将产卵量降低97%。本研究结果为脊椎动物体内存在平衡型嗅觉拮抗作用提供了实证，并为防控作为劳伦琴五大湖（Laurentian Great Lakes）破坏性入侵物种的海七鳃鳗产卵行为提供了可行策略。