A Transcriptome-based Perspective of Meiosis in Dinoflagellates

There is increasing interest in the possibility of sexual recombination in dinoflagellates, especially those symbiotic with coral, since recombination may be able to augment genetic diversity and reduce levels of coral bleaching. Several previous studies have addressed this in Symbiodinium by querying sequence databanks with a list of 51 genes termed a meiosis detection toolkit. Here, we have constructed an expanded list of 307 genes involved in meiosis in budding yeast. We find the genes involved in the major regulatory steps in yeast meiosis are also found in dinoflagellates, as are many of the genes involved in recombination. In contrast, few genes involved in forming the synaptonemal complex or forming spores are conserved. We further note that the meiosis-related genes absent in dinoflagellates are also as a general rule absent from other protists in the closely related apicomplexa and the ciliates. We conclude the symbiotic dinoflagellates are as able to undergo meiosis as are other protists.