Speaker: 

Prof. Shinichiro Maruyama, Laboratory of Integrated Biology, The University of Tokyo [website]

 

Title:

 

Abstract:

Coral reefs are sustained by a symbiotic relationship known as photosymbiosis, where microalgae reside, mostly intracellularly, within the non-photosynthetic hosts. The photosymbiosis has a profound impact on the host's physiology, potentially influencing coral bleaching, mass spawning, and broader ecosystem dynamics. To unravel the intricate mechanisms underlying photosymbiosis, we employ a reductionist approach, breaking down the process into its fundamental components. Our research using coral symbiont algae has revealed that, in addition to the photosynthetic capacity, cell wall regulation in response to environmental changes plays a crucial role in carbon cycling within the photosymbiosis. 
Furthermore, we are expanding our investigations to encompass other photosymbiotic systems and, in particular, delving into the previously understudied photosymbioses between amoebae and green algae. We have established methods to quantitatively assess the symbiosis capacity of symbiotic algae and isolated a novel photosymbiotic amoeba from the field environment. These efforts contribute to our understanding of the diversity and evolutionary origins of photosymbioses.