Figure 1.

Sphaeroforma arctica Exhibits a Uniform and Synchronizeable Coenocytic Cycle

(A) A cladogram representing the position of S. arctica within eukaryotes based on [14].

(B) Representative differential interference contrast microscopy (DIC), DAPI, and merged images of cells from the corresponding coenocytic cell cycle stages: newborn cells (first row), multinuclear coenocyte (second row), cellularized coenocyte (third row), and burst (fourth row). White arrows represent a newborn cell with two nuclei. Scale bar in first, second, and third rows: 10 microns; in fourth row: 20 microns.

(C) A schematic illustration of the S. arctica cell cycle, corresponding to the images in (B). Blue spots represent nuclei.

(D) DNA content profile assessed by flow cytometry across the time course of cell populations grown in 1× MB, 12°C, 1:100 initial dilution of a saturated culture. Approximately 5,000 cells were measured at each time point.

(E) Quantification of fractions of population per DNA content profiles bin.

See also Figures S1 and S2.