**eLife 8:e45292 Figure 5: A chloroplast localization for chloramphenicol acetyl transferase.**

Dinoflagellate algae are of enormous ecological importance as they form symbiosis with corals, providing fixed carbon to their hosts. Environmental stresses such as raised temperature lead to breakdown of the symbiosis, expulsion of the dinoflagellates, and coral bleaching. Little is known about why the symbiosis breaks down, although the generation of reactive oxygen species in the chloroplast is probably involved. Dinoflagellates have long been resistant to transformation, which has hampered research into bleaching.

With funding from the Gordon and Betty Moore Foundation, Chris Howe’s lab in the Cambridge Biochemistry Department has succeeded in transforming the chloroplast of a model dinoflagellate, Amphidinium carterae (Nimmo IC et al. (2019) Genetic transformation of the dinoflagellate chloroplast. eLife 8:e45292 DOI: https://doi.org/10.7554/eLife.45292). They exploited the highly unusual organisation of the chloroplast genome – fragmented into plasmid-like ‘minicircles’ – to make shuttle vectors for biolistic transformation. This should open the way for studies on how environmental stresses affect dinoflagellate chloroplast function and ultimately lead to coral bleaching.