The nutrient recycling system in the Paramecium and Chlorella photosymbiosis

Photosymbiosis, an endosymbiotic relationship between a heterotrophic host and a unicellular algal endosymbiont, is observed in many eukaryotic lineages. While photosymbioses are prevalent in oligotrophic environments, how they function and provide an advantage under such conditions remains largely unknown. To address these issues, in this study, we examined the behaviour of the ciliate Paramecium bursaria hosting Chlorella endosymbionts under nitrogen- and prey-depleted conditions. In this project, we sequenced the transcriptomes of both the host Paramecium bursaria and its algal endosymbiont Chlorella variabilis under various culture and light conditions, all within the endosymbiotic state. Additionally, we analyzed the transcriptomes of P. bursaria in the aposymbiotic state to compare differences between the symbiotic and aposymbiotic states.