PHYSIOLOGY OF AN OBLIGATE PHOTOAUTOTROPH (CHLAMYDOMONAS MOEWUSII). I. CHARACTERISTICS OF SYNCHRONOUSLY AND RANDOMLY REPRODUCING CELLS AND AN HYPOTHESIS TO EXPLAIN THEIR POPULATION CURVES.

摘要: SYNOPSIS. Cultures of Chlamydomonas moewusii begun with log-phase cells any age had the same lag phases and showed slight but demonstrable synchronous division. Those stationary-phase longer pronounced synchronously reproductive tendencies. grown under favorable or unfavorable conditions, their compared, behaved like log- respectively. Both stationary phase unfavorably cultures shared some characteristics synchronized by light-dark cycling. A cycled population divides in direct response to cycle, not as a result being transferred from one medium another. Synchronous division will occur 8-fold increases initial cell densities low 10 cells/ml high 100,000 cells/ml. Initial concentrations above 100,000/ml bursts less than 8 times number. Cycled continue divide when exposed continuous illumination for an additional 24 hr (i.e., 1 entire “cycle” period). After 12 more hr, they exponentially. Continuously illuminated young log subjected regimen begin growing dividing end 1st 12-hr dark period during 2nd 24-hr cycle). The cycle is described cytologkally quantitatively, degree synchrony each analyzed. comparing data randomly cultures, hypothesis suggested explain exponential growth