. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SLIME MOLDS 449 gregateless individuals could respond to the stimulus imposed by wild type where the population density of the wild type was so low that, alone, they could not form centers. Suspensions of washed Nc-4 wild type and agg-53, prepared according to the procedure previously described, were counted in the Levy hemocytometer and ap- propriate dilutions were made. From these, mixtures were arranged such that they contained a constant number of Nc-4 cells but varying numbers of aggregate- less individuals. For example
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SLIME MOLDS 449 gregateless individuals could respond to the stimulus imposed by wild type where the population density of the wild type was so low that, alone, they could not form centers. Suspensions of washed Nc-4 wild type and agg-53, prepared according to the procedure previously described, were counted in the Levy hemocytometer and ap- propriate dilutions were made. From these, mixtures were arranged such that they contained a constant number of Nc-4 cells but varying numbers of aggregate- less individuals. For example, in one experiment the mixtures all contained X 10f> cells/cc. of wild type while the numbers of agg-53 cells/cc. ranged from X 105 to X 107. Replicate drops of cc. volume were distributed on 80-. O -O O The relation between the number of centers formed and the number of agg-53 present in mixtures with Wild Type NC-4. -ft n m No agg-53 eel Is/drop x 10 -5 FIGURE 1. Curve I refers to mixtures containing X 103 wild type cells/sample with various numbers of agg-53 cells. Curve II refers to mixtures containing X 103 wild type/ sample and Curve III, X 103. minimal agar, 10 drops to a plate and two or three plates for each mixture. Thus, the number of Nc-4/drop was X 103 while the numbers of agg-53/drop varied between 5 X 103 and X 105. Drops were also dispensed from control suspen- sions containing either Nc-4 or agg-53 in concentrations comparable to those in the experimental suspensions. After distribution of the drops, the plates were allowed to stand with covers ajar until the drops had dried. The plates were incubated at 22° C. and twice during the following 48 hours the drops were examined either under 20 X or 100 X magnification in order to count the aggregates or fruiting bodies derived Please note that these images are extracted from scanned page images that may have been digitally enhanced for readab
Size: 1078px × 2319px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
