Daily life cycle of endospore-forming Epulopiscium-like symbionts.
Endospore formation in some Epulopiscium-like symbionts follows a daily cycle:
A) Polar septa are formed at the poles of the cell.
B) Forespores become engulfed.
C) Forespores gradually increase in size within the mother cell through the day.
D) In late afternoon, final preparations for endospore dormancy.
E) Endospores mature and remain dormant throughout most of the night.
F) Just before sunrise, the endospores germinate and are released from mother cell to repeat the cycle.