Methods and Materials

Do A. elegantissima and S. muscatinei synchronize their growth rates?

We used DNA staining and cell cycle analysis to determine if A. elegantissima and S. muscatinei synchronize their growth rates to control symbiont densities. We collected 11 anemones at a +0.2 m tide level and held them for 2 days in an indoor, flow-through sea table. We then clipped tentacles from A. elegantissima and gastrodermal cells (containing S. muscatinei) were extruded from the cut tentacle ends. Gastrodermal cells were lysed and chlorophyll from S. muscatinei was removed. All cell nuclei were dyed with ethidium bromide and the cells were run through a flow cytometer to count the number of cells in each cell cycle phase. We then measured the percentage of host and symbiont cells in G1, S and G2/M phases of cell division.