Figure 4.

Starvation-induced dispersal increases BB density and formation of a caudal cilium

(A) BB localization (α-TtCen1; greyscale) and cell morphology in D4, D5, and B2086 cells from cycling (fed) and starved conditions (scale bar, 10 μm).

(B) Starved D4, D5, and B2086 cells swim faster than fed cells (p < 0.0001, 0.02, and 0.01, respectively). Maximum speeds of both B2086 and D5 are 2.8-fold faster than the maximum speed of D4. The measurements for swim speeds were taken from 3 biological replicates n = 30.2 ± 2.4 cells per condition (total of 181 cells). Data are represented as strain mean (black bar), the experimental means (hollow circles), and individual cell speed (dots).

(C) Starved cells increase in cell aspect ratio after starvation for all strains (p < 0.0001 for D4, D5, and B2086). The measurements for aspect ratio were taken from 3 biological replicates n = 36.6 ± 4.7 cells per condition (total of 220 cells). Data are represented as strain mean (black bar), the experimental means (hollow circles), and individual cell aspect ratio (dots).

(D) Cell length decreases in all strains after starvation (D4, p < 0.0001; D5, p = 0.01; B2086, p < 0.0001). The measurements for cell length were taken from 3 biological replicates n = 36.6 ± 4.7 cells per condition (total of 220 cells). Data are represented as strain mean (black bar), the experimental means (hollow circles), and individual cell length (dots).

(E) Cell width decreases after starvation (p < 0.0001 for D4, D5, and B2086). The measurements for cell width were taken from 3 biological replicates n = 36.6 ± 4.7 cells per condition (total of 220 cells). Data are represented as strain mean (black bar), the experimental means (hollow circles), and individual cell width (dots).

(F) Starved D4 and B2086 (D4 n = 604 cells, B2086 n = 555 cells) cells do not generate a caudal cilium while starved D5 cell (D5 n = 600 cells) exhibit a subpopulation of cells with a caudal cilium (p < 0.0001). Data are represented as strain mean and standard deviation (black bars), and the experimental means (hollow circles).

(G) Model of D5 cell and cilia location (left). Fluorescence images of the caudal or cell posterior end in starved D5 cells. BBs are stained for BBs (α-TtCen1, red) and cilia (α -glutamylated and α-α-tubulin; green) (scale bar, 5 μm).

(H) The caudal cilium is longer than the average cortical medial cilium (p < 0.0001) (n = 26 caudal cilia from 26 cells, n = 300 cilia from 30 cells). Data are represented as a morphotype mean (black bar), the experimental means (hollow circles/squares), and mean cilia length of individual cells (dots).

(I) Starved D5 cells with a caudal cilium have an increased aspect ratio (narrow cell shape) compared with starved D5 cells without a caudal cilium (p < 0.0001) (n = 26 cells with caudal cilia, n = 42 cells without caudal cilia). Data are represented as the morphotype mean (black bar), the experimental means (hollow circles/squares), and the aspect ratio of individual cells (dots).