. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. OPTIMIZING FOR CHEMOKINESIS 15° C 35° C. 1 ) O2 tension 2)pH 3 ) Cell number 4 ) Cell volume 5 ) ATP / ADP content 6 ) Chemoattraction 7 ) Swimming speed a) !b) (c)(d) B C Figure 1. The experimental setup giving rise to different oxygen tensions (a. b, c, d). Cells grown at 35°C in Fernbach flasks (A) were transferred to starvation at a cell concentration of 5 X 104 cells ml"1. Initially, Hepes-KOH buffer. pH = was used as the starvation medium. The cell suspension was divided into the following aliquo
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. OPTIMIZING FOR CHEMOKINESIS 15° C 35° C. 1 ) O2 tension 2)pH 3 ) Cell number 4 ) Cell volume 5 ) ATP / ADP content 6 ) Chemoattraction 7 ) Swimming speed a) !b) (c)(d) B C Figure 1. The experimental setup giving rise to different oxygen tensions (a. b, c, d). Cells grown at 35°C in Fernbach flasks (A) were transferred to starvation at a cell concentration of 5 X 104 cells ml"1. Initially, Hepes-KOH buffer. pH = was used as the starvation medium. The cell suspension was divided into the following aliquots: 50 ml in each of four 500-ml Fernbach flasks (a), 80 ml in each of four 250-ml Ehrlenmeyer flasks (b), 80 ml in each of four 100-ml Ehrlenmeyer flasks (c), and four 100-ml Ehrlenmeyer flasks filled to the top with the cell suspension (d). As indicated in (B), the cells were incubated in the starvation medium at 15°, 21°, 28°, and 35°C. respectively. The chemoattraction and a number of physi- ological parameters were determined after 16 h of starvation (C). The results of a representative experiment are summarized in Table I. For the quantitative analysis of the chemosensory response of the cells, we used a capillary assay as illustrated in Figure 2. Proteose peptone (PP) in a concentration of 1 mg mP1 was used as the attractant. All cell suspensions were maintained at 28°C for half an hour before the start of the assay. The assays were incubated for 45 min at 28°C. The assay temperature was chosen in accordance with earlier findings (Leick el al, 1990). Recent studies have confirmed that the optimal temperature for chemokinesis in Tetrahymena thermophila is about 28°C (Koppelhus et 1994). Five assays testing the effect of proteose pep- tone and five control assays were performed simulta- neously. The mean values are listed in Table I and the standard deviations were calculated and listed for some selected measurements. Results We investigated the influence of
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
