Dissertation Proposal - The University of Arizona Campus Repository

Finally, the data also shows that rmax ∝ N 0.33 as used in the model (Eq. 7b). When
analyzing the maximum radius measured on reproductive cells before the division phase
versus N, even without correcting for initial cell size (not measured), SLR yields rmax ∝ N
0.31 , not significantly different from 0.33 (s.e. = 0.07, n = 8, r 2 = 0.87; Appendix A).
D- Differences between Developmental Programs and Mutant Forms
I now compare differences in the swimming force and speed between developmental
programs and mutant forms. When performing multiple linear additive regression
analysis (MLR) on newly hatched colonies (including the mutant forms) I find that the
exponent of the relation between Vup and N becomes 0.26 (s.e. 0.02). All mutant colonies,
D2 and D3 colonies, and non-spherical (G. pectorale) colonies have on average a lower
Vup. V. rousseletii has on average a higher Vup than colonies that do not retain robust
cytoplasmatic bridges (Table 5, n = 26, r 2 =0.98).
The differences in Vup among different colony designs is an indication of how
problems may arise as colonies adjust the three factors involved in motility: total
swimming force Nqf, negative gravitational force ∆Mg, and drag 6πηR. Since lag -
colonies have on average a larger R (Figure 5), their Vup is negatively affected due to an
increase in drag. In contrast, when they hatch V. rousseletii colonies have a lower R and
∆M because they retain robust cytoplasmatic bridges and their flagellated and
reproductive cells are significantly smaller compared to the other species (Figure 5); this
positively affects Vup. D2 and D3 colonies have on average a lower Vup than the other
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