Abstract Title
Control of Gamete/Vegetative Transition in Chlamydomonas
Abstract
The single-celled green alga Chlamydomonas reinhardtii divides mitotically in a nitrogen-containing growth medium and under visible white light. Upon removal of nitrogen from the growth medium, and under visible white light, Chlamydomonas cells differentiate into gametes. When nitrogen is restored to the growth medium, the cells re-enter the mitotic cell cycle. We have found that a delay exists between the addition of nitrogen and increase in DNA content and mitotic increase in cell numbers; we also find that this delay is lengthened when cells are exposed to a DNA-damaging treatment immediately prior to the addition of nitrogen to the medium. This finding suggests that a DNA damage-induced checkpoint exists between the gametic and vegetative states of Chlamydomonas.
Control of Gamete/Vegetative Transition in Chlamydomonas
The single-celled green alga Chlamydomonas reinhardtii divides mitotically in a nitrogen-containing growth medium and under visible white light. Upon removal of nitrogen from the growth medium, and under visible white light, Chlamydomonas cells differentiate into gametes. When nitrogen is restored to the growth medium, the cells re-enter the mitotic cell cycle. We have found that a delay exists between the addition of nitrogen and increase in DNA content and mitotic increase in cell numbers; we also find that this delay is lengthened when cells are exposed to a DNA-damaging treatment immediately prior to the addition of nitrogen to the medium. This finding suggests that a DNA damage-induced checkpoint exists between the gametic and vegetative states of Chlamydomonas.