Limits to the cellular control of sequestered cryptophyte prey in the marine ciliate Mesodinium rubrum

作者：Andreas Altenburger, Huimin Cai, Qiye Li, Kirstine Drumm, Miran Kim, Yuanzhen Zhu, Lydia Garcia‐Cuetos, Xiaoyu Zhan, Per Juel Hansen, Uwe John, Shuaicheng Li, Nina Lundholm · 发表于：The ISME Journal · 年份：2020 · DOI：10.1038/s41396-020-00830-9 · 被引用次数：28 · 研究领域：Protist diversity and phylogeny、Microbial Community Ecology and Physiology、Genomics and Phylogenetic Studies

The marine ciliate Mesodinium rubrum is famous for its ability to acquire and exploit chloroplasts and other cell organelles from some cryptophyte algal species. We sequenced genomes and transcriptomes of free-swimming Teleaulax amphioxeia, as well as well-fed and starved M. rubrum in order to understand cellular processes upon sequestration under different prey and light conditions. From its prey, the ciliate acquires the ability to photosynthesize as well as the potential to metabolize several essential compounds including lysine, glycan, and vitamins that elucidate its specific prey dependency. M. rubrum does not express photosynthesis-related genes itself, but elicits considerable transcriptional control of the acquired cryptophyte organelles. This control is limited as light-dependent transcriptional changes found in free-swimming T. amphioxeia got lost after sequestration. We found strong transcriptional rewiring of the cryptophyte nucleus upon sequestration, where 35% of the T. amphioxeia genes were significantly differentially expressed within well-fed M. rubrum. Qualitatively, 68% of all genes expressed within well-fed M. rubrum originated from T. amphioxeia. Quantitatively, these genes contributed up to 48% to the global transcriptome in well-fed M. rubrum and down to 11% in starved M. rubrum. This tertiary endosymbiosis system functions for several weeks, when deprived of prey. After this point in time, the ciliate dies if not supplied with fresh prey cells. M. rub...