Fig. 1: Morphological characteristics of Medakamo hakoo.

a Fluorescence images merged with a phase-contrast image of M. hakoo (mh), Cyanidioschyzon merolae (cm), and Saccharomyces cerevisiae (sc). SYBR Green signals appear green. Red signals are autofluorescence from the chlorophyll in chloroplasts. The scale bar indicates 1 µm. b Image of the SYBR Green fluorescence only for the sample presented in panel a. c–e Highly magnified images of M. hakoo. c Phase-contrast and autofluorescence image. The scale bar indicates 1 µm. d SYBR Green signals. Long and short arrows indicate the nuclear and chloroplast DNA, respectively. e Merged image of (c) and (d). f Transmission electron microscopy image of M. hakoo; no, n, v, mt and cp represent the nucleolus, nucleus, vacuole, mitochondrion, and chloroplast, respectively. Arrowheads indicate electron-dense structures. The scale bar indicates 500 nm. g Schematic image of the M. hakoo cell structure; no, n, g, mt, v, s, and cp indicate the nucleolus, nucleus, Golgi apparatus, mitochondrion, vacuole, starch, and chloroplast, respectively. h Synchronization culture of M. hakoo. The schematic diagram with images of SYBR Green fluorescence presents the following cell stages: single-cell stage (I), two-cells-combined stage (II), tetrad stage (III), and dissection stage (IV). The M. hakoo cells were treated with a 12-h light/12-h dark cycle. Totally, 4268 cells were counted. The counts at each time point are provided in Supplementary Data 6. The scale bars indicate 500 nm. i Schematic diagram of the M. hakoo lifecycle; n, mt, and cp indicate the nucleus, mitochondrion, and chloroplast, respectively.