How to upgrade stolen organelles into permanent plastids: A comparative transcriptomic perspective

Plastids arose through an ancient symbiotic relationship between eukaryotic hosts and photosynthetic prey. However, the evolutionary steps by which a temporary association becomes a permanent organelle remain poorly understood. Tertiary plastids derived from diatoms in dinotom dinoflagellates offer a rare opportunity to study organellogenesis, as members of this group contain plastids at different evolutionary stages within the same genus. Here, we present a comparative transcriptomic analysis of two dinotoms at different plastidial stages: Durinskia capensis at the kleptoplasty stage, alongside its kleptoplastid-source diatom Nitzschia captiva, and its close relative D. kwazulunatalensis at an early permanent stage. This is the transcriptomic data for D. kwazulunatalensis, which is a mixture of transcripts expressed from the nuclei of both the host dinoflagellate and its endosymbiotic diatoms Simonsenia sp.