St01-0.4hpf

The zygote period (0-0.9 hr after fertilization at 18°C) consisted of a single stage, stage 1 extending from fertilisation event up to the end of the first mitotic cycle.

The cross-section is lower. In addition to the cortical actin filaments beneath the cell membranes (arrows), the staining could detect the cytosolic actin filaments surrounding the nuclei (arrowheads). Scale bar = 50 micro m.