Richard Dorrell and Chris Howe have published a paper "Functional remodeling of RNA processing in replacement chloroplasts by pathways retained from their predecessors" in PNAS.
Chloroplasts arise via the integration of a host and a photosynthetic symbiont. Some photosynthetic eukaryotes appear to have replaced their original chloroplasts with others derived from different organisms, however, it was not previously known whether the original symbiosis impacts on the biology of the replacement. Focussing on transcript processing in the dinoflagellate alga Karenia mikimotoi, which is one of several species of dinoflagellate known to harbour replacement chloroplasts, Dorrell and Howe demonstrate that pathways derived from the original symbiont may not only be retained following chloroplast replacement, but may substantially alter the biology of the replacement. These results add a significant new dimension to current theories of chloroplast evolution.