Predator lipids induce paralytic shellfish toxins in bloom-forming algae.
Interactions among microscopic planktonic organisms underpin the functioning of open ocean ecosystems. With few exceptions, these organisms lack advanced eyes and thus rely largely on chemical sensing to perceive their surroundings. However, few of the signaling molecules involved in interactions among marine plankton have been identified. We report a group of eight small molecules released by copepods, the most abundant zooplankton in the sea, which play a central role in food webs and biogeochemical cycles. The compounds, named copepodamides, are polar lipids connecting taurine via an amide to isoprenoid fatty acid conjugate of varying composition. The bloom-forming dinoflagellate Alexandrium minutum responds to pico- to nanomolar concentrations of copepodamides with up to a 20-fold increase in production of paralytic shellfish toxins. Different copepod species exude distinct copepodamide blends that contribute to the species-specific defensive responses observed in phytoplankton. The signaling system described here has far reaching implications for marine ecosystems by redirecting grazing pressure and facilitating the formation of large scale harmful algal blooms.
Department of Biological and Environmental Sciences, University of Gothenburg, SE 450 30 Göteborg, Sweden; erik.selander@bioenv.gu.se.
Erik
E
Selander
School of Biology and School of Chemistry and Biochemistry, Aquatic Chemical Ecology Center, Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332; Department of Biological and Environmental Sciences-Tjärnö, University of Gothenburg, SE 452 96 Strömstad, Sweden; and.
Julia
J
Kubanek
Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE 171 77 Stockholm, Sweden.
Mats
M
Hamberg
Department of Biological and Environmental Sciences, University of Gothenburg, SE 450 30 Göteborg, Sweden;
Mats X
MX
Andersson
Department of Biological and Environmental Sciences-Tjärnö, University of Gothenburg, SE 452 96 Strömstad, Sweden; and.
Gunnar
G
Cervin
Department of Biological and Environmental Sciences-Tjärnö, University of Gothenburg, SE 452 96 Strömstad, Sweden; and.
Henrik
H
Pavia
D000577:Amides / Q000032:analysis / Q000494:pharmacology*; D000818:Animals; D002450:Cell Communication / Q000502:physiology; D005591:Chemical Fractionation; D033342:Copepoda / Q000737:chemistry / Q000502:physiology*; D004141:Dinoflagellida / Q000187:drug effects / Q000378:metabolism*; D020387:Food Chain; D057097:Harmful Algal Bloom / Q000502:physiology*; D009682:Magnetic Resonance Spectroscopy; D009792:Oceans and Seas; D013045:Species Specificity; D013548:Sweden
D000577:Amides
Alexandrium; harmful algal bloom; inducible defense; lipid signaling; paralytic shellfish toxin