In Archaeplasidial Viridiplantae, the regulation of chloroplast gene expression acts almost exclusively at the post-transcriptional level, but this question has not been addressed so far for prominent photosynthetic eukaryotes of the oceans like diatoms that acquired their plastid from a red alga through secondary and tertiary endosymbiosis. We use transcriptomics and proteomics approaches to elucidate levels of regulation (transcriptional or post-transcriptional) at play in diatoms (see also Theme 3). To further understand the nature of the nuclear control of plastid gene expression in diatoms, we combine these functional approaches to comparative genomics and machine learning approaches to understand how genetic novelties gain new functions at evolutionary time scales. We are also exploring the evolutionary origin of the CES process, a translational regulatory process in the organelles discovered in our laboratory, which probably arose as a consequence of endosymbiosis (see also Theme 1)
