TY - JOUR
T1 - Green fluorescence from cnidarian hosts attracts symbiotic algae
AU - Aihara, Yusuke
AU - Maruyama, Shinichiro
AU - Baird, Andrew H.
AU - Iguchi, Akira
AU - Takahashi, Shunichi
AU - Minagawa, Jun
N1 - Funding Information:
We thank Nami Okubo for her advice on the conception of this study and Susumu Yoshizawa for discussion on rhodopsin protein evolution. We thank Yasuhiro Kamei for his advice regarding the use of the Okazaki Large Spectrograph. We thank Toshiyuki Sazi for his advice on construction of the experimental equipment. We thank the Model Plant Research Facility, National Institute for Basic Biology BioResource Center for their technical support. This work was supported by Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (KAKENHI) 18K19240 (to S.T.), 16K14814 (to Y.A.), and 16H06552 (to J.M.); NIBB Collaborative Research Program 15-362, 16-334, and 17-310 (to S.M.); and Gordon & Betty Moore Foundation's Marine Microbiology Initiative 4985 (to S.M., S.T., and J.M.). Computational resources were provided by the Data Integration and Analysis Facility at the National Institute for Basic Biology. A.H.B. was supported by the Australian Research Council Centre of Excellence for Coral Reef Studies.
Funding Information:
ACKNOWLEDGMENTS. We thank Nami Okubo for her advice on the conception of this study and Susumu Yoshizawa for discussion on rhodopsin protein evolution. We thank Yasuhiro Kamei for his advice regarding the use of the Okazaki Large Spectrograph. We thank Toshiyuki Sazi for his advice on construction of the experimental equipment. We thank the Model Plant Research Facility, National Institute for Basic Biology BioResource Center for their technical support. This work was supported by Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (KAKENHI) 18K19240 (to S.T.), 16K14814 (to Y.A.), and 16H06552 (to J.M.); NIBB Collaborative Research Program 15-362, 16-334, and 17-310 (to S.M.); and Gordon & Betty Moore Foundation’s Marine Microbiology Initiative 4985 (to S.M., S.T., and J.M.). Computational resources were provided by the Data Integration and Analysis Facility at the National Institute for Basic Biology. A.H.B. was supported by the Australian Research Council Centre of Excellence for Coral Reef Studies.
Publisher Copyright:
© 2019 National Academy of Sciences. All Rights Reserved.
PY - 2019/2/5
Y1 - 2019/2/5
N2 - Reef-building corals thrive in nutrient-poor marine environments because of an obligate symbiosis with photosynthetic dinoflagellates of the genus Symbiodinium. Symbiosis is established in most corals through the uptake of Symbiodinium from the environment. Corals are sessile for most of their life history, whereas free-living Symbiodinium are motile; hence, a mechanism to attract Symbiodinium would greatly increase the probability of encounter between host and symbiont. Here, we examined whether corals can attract free-living motile Symbiodinium by their green fluorescence, emitted by the excitation of endogenous GFP by purple-blue light. We found that Symbiodinium have positive and negative phototaxis toward weak green and strong purple-blue light, respectively. Under light conditions that cause corals to emit green fluorescence, (e.g., strong blue light), Symbiodinium were attracted toward live coral fragments. Symbiodinium were also attracted toward an artificial green fluorescence dye with similar excitation and emission spectra to coral-GFP. In the field, more Symbiodinium were found in traps painted with a green fluorescence dye than in controls. Our results revealed a biological signaling mechanism between the coral host and its potential symbionts.
AB - Reef-building corals thrive in nutrient-poor marine environments because of an obligate symbiosis with photosynthetic dinoflagellates of the genus Symbiodinium. Symbiosis is established in most corals through the uptake of Symbiodinium from the environment. Corals are sessile for most of their life history, whereas free-living Symbiodinium are motile; hence, a mechanism to attract Symbiodinium would greatly increase the probability of encounter between host and symbiont. Here, we examined whether corals can attract free-living motile Symbiodinium by their green fluorescence, emitted by the excitation of endogenous GFP by purple-blue light. We found that Symbiodinium have positive and negative phototaxis toward weak green and strong purple-blue light, respectively. Under light conditions that cause corals to emit green fluorescence, (e.g., strong blue light), Symbiodinium were attracted toward live coral fragments. Symbiodinium were also attracted toward an artificial green fluorescence dye with similar excitation and emission spectra to coral-GFP. In the field, more Symbiodinium were found in traps painted with a green fluorescence dye than in controls. Our results revealed a biological signaling mechanism between the coral host and its potential symbionts.
KW - Coral
KW - Fluorescence
KW - GFP
KW - Phototaxis
KW - Symbiosis
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U2 - 10.1073/pnas.1812257116
DO - 10.1073/pnas.1812257116
M3 - Article
C2 - 30670646
AN - SCOPUS:85061137735
VL - 116
SP - 2118
EP - 2123
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 6
ER -