An interesting question from the POV of the coevolution of symbiont genomes:
"One of the unsolved mysteries of kleptoplasty, particularly in animal cells, is how the host is able to maintain algal chloroplasts in a photosynthetically competent state for long periods, after stripping them of their nuclear entourage."
#Evolution #Symbiosis #Genomics
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001857