Data from: Phylogenetic distribution of a male pheromone that may exploit a nonsexual preference in lampreys

Pheromones are among the most important sexual signals used by organisms throughout the animal kingdom. However, few are identified in vertebrates, leaving the evolutionary mechanisms underlying vertebrate pheromones poorly understood. Pre-existing biases in receivers’ perceptual systems shape visual and auditory signaling systems, but studies on how receiver biases influence the evolution of pheromone communication remain sparse. The lamprey Petromyzon marinus uses a relatively well-understood suite of pheromones and offers a unique opportunity to study the evolution of vertebrate pheromone communication. Previous studies indicate that male signaling with the mating pheromone 3-keto petromyzonol sulfate (3kPZS) may exploit a nonsexual attraction to juvenile-released 3kPZS that guides migration into productive rearing habitat. Here, we infer the distribution of male signaling with 3kPZS using a phylogenetic comparison comprising six of ten genera and two of three families. Our results indicate that only P. marinus and Ichthyomyzon castaneus release 3kPZS at high rates. Olfactory and behavioral assays with P. marinus, I. castaneus and a subset of three other species that do not use 3kPZS as a sexual signal indicate that male signaling might drive the evolution of female adaptations to detect 3kPZS with specific olfactory mechanisms and respond to 3kPZS with targeted attraction relevant during mate search. We postulate that 3kPZS communication evolved independently in I. castaneus and P. marinus, but cannot eliminate the alternative that other species lost 3kPZS communication. Regardless, our results represent a rare macroevolutionary investigation of a vertebrate pheromone and insight into the evolutionary mechanisms underlying pheromone communication.

信息素（Pheromones）是整个动物界生物体所使用的最重要的性信号之一。然而，脊椎动物（vertebrates）中已被鉴定的信息素寥寥无几，使得人们对脊椎动物信息素背后的进化机制知之甚少。接收者感知系统中预先存在的感知偏倚会塑造视觉与听觉信号系统，但关于接收者偏倚如何影响信息素通信进化的研究仍寥寥无几。海七鳃鳗（Petromyzon marinus）拥有一套相对研究透彻的信息素系统，为研究脊椎动物信息素通信的进化提供了独特的契机。既往研究表明，雄性通过交配信息素3-酮海七鳃鳗醇硫酸盐（3-keto petromyzonol sulfate，3kPZS）进行信号传递，可能是利用了幼体释放的3kPZS所具有的非性吸引效应——这种效应原本用于引导个体迁移至适宜的育幼栖息地。本研究通过包含10个属中的6个属、3个科中的2个科的系统发育比较（phylogenetic comparison），推断了雄性释放3kPZS的物种分布范围。研究结果显示，仅海七鳃鳗和栗色七鳃鳗（Ichthyomyzon castaneus）会高水平释放3kPZS。针对海七鳃鳗、栗色七鳃鳗，以及另外3种未将3kPZS作为性信号的物种开展的嗅觉与行为测定实验表明，雄性的信号传递可能推动雌性演化出特异性嗅觉机制以识别3kPZS，并产生与配偶搜寻相关的定向趋性应答。我们推测，3kPZS通信在栗色七鳃鳗和海七鳃鳗中独立演化，但也无法排除其他物种丢失了3kPZS通信能力这一替代假说。无论如何，本研究是罕见的脊椎动物信息素宏观进化研究，为揭示信息素通信的进化机制提供了新的见解。