Symbiotic lifestyle triggers drastic changes in the gene expression of the algal endosymbiont, Breviolum minutum (Symbiodiniaceae)

Symbiodiniaceae algae are known to differ in their morphology, cell cycle, and life history attributes in hospite and in culture. We conducted a comparison of gene expression profiles of cultured Breviolum minutum (ITS2 type B1) (formerly Clade B) with those of algae of the same strain, freshly isolated from the Exaiptasia pallida sea anemone. We looked for differentially expressed genes between the two lifestyles in order to understand the cellular processes that distinguish them. We focused on up- and down-regulated transporters, with a purpose of pinpointing candidates that may assist with the exchange of compounds between the host and the symbiont.