Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112, USA.
Department of Biological Sciences, California State University, Los Angeles, CA 90032, USA.
Sci Adv. 2024 Nov;10(44):eadp8643. doi: 10.1126/sciadv.adp8643. Epub 2024 Oct 30.
Secondary metabolites often function as antipredator defenses, but when bioactive at low concentrations, their off-target effects on other organisms may be overlooked. Candidate "keystone molecules" are proposed to affect community structure and ecosystem functions, generally originating as defenses of primary producers; the broader effects of animal chemistry remain largely unexplored, however. Here, we characterize five previously unreported polyketides (alderenes A to E) biosynthesized by sea slugs reaching exceptional densities (up to 9000 slugs per square meter) in Northern Hemisphere estuaries. Alderenes comprise only 0.1% of slug wet weight, yet rendered live slugs or dead flesh unpalatable to three co-occurring consumers, making a potential food resource unavailable and redirecting energy flow in critical nursery habitat. Alderenes also displaced infauna from the upper sediment of the mudflat but attracted ovipositing snails. By altering communities, such compounds may have unexpected cascading effects on processes ranging from bioturbation to reproduction of species not obviously connected to the producing organisms, warranting greater attention by ecologists.
次生代谢物通常具有抗捕食防御作用，但在低浓度时，其对其他生物的非靶向效应可能被忽视。候选“关键分子”被认为会影响群落结构和生态系统功能，它们通常源自初级生产者的防御；然而，动物化学的更广泛影响在很大程度上仍未得到探索。在这里，我们描述了由海蛞蝓合成的五种以前未报道的聚酮化合物（桤木烯 A 至 E），这些海蛞蝓在北半球河口达到异常的密度（每平方米多达 9000 只）。桤木烯仅占蛞蝓湿重的 0.1%，但使活体蛞蝓或死肉变得不可口，使三种共存的消费者无法获得潜在的食物资源，并在关键的育苗栖息地重新分配能量流。桤木烯还将底栖动物从泥滩的上层沉积物中驱赶出来，但吸引了产卵的蜗牛。通过改变群落，这些化合物可能对从生物扰动到与产生它们的生物没有明显联系的物种的繁殖等过程产生意想不到的级联效应，这值得生态学家给予更多关注。
