Table 1.
F-actin polarization and formation dynamics
| Genotype | Lifetimea | Frequency of polarization axis switchb | F-actin patch co-existence timec | Dominant F-actin patch formation ratee | Dominant F-actin patch disassembly rate | Peak volume of dominant ectopic F-acting |
| min | Counts per hour | min | µm3/min | µm3/min | µm3 | |
| unc-6(ev400) | 25.9 ± 2.1h (n = 12) | 2.5 ± 0.2h (n = 12) | 9.6 ± 1.1 (n = 32) | 0.697 ± 0.17 (n = 9) R2 = 0.92 | 0.91 ± 0.12 (n = 12) R2 = 0.97 | 15.4 ± 1.1 (n = 20) |
| unc-6(ev400); Ex[dorsal UNC-6] | >69.3 ± 5.9 (n = 8 with one stable UNC-6 source) | 0 (n = 8, with one stable UNC-6 source) | N.A.d | 0.669 ± 0.12 (n = 6) R2 = 0.97 | N.A.f | 18.1 ± 2.7 (n = 7) |
| madd-2(ok2226); unc-6(ev400) | >82.7 ± 12.2 (n = 6) | <0.8 ± 0.1i (n = 6) | ND | 0.200 ± 0.06j (n = 5) R2 = 0.86 | 0.707 ± 0.23 (n = 5) R2 = 0.80 | 16.5 ± 2.3 (n = 6) |
Data are presented as mean ± SEM. N.A., not applicable.
The lifetime of the polarized F-actin patches in most unc-6(ev400); Ex[dorsal UNC-6] and madd-2(ok2226); unc-6(ev400) mutant animals exceeded the corresponding time-lapse length. Thus, we used the recorded times, which are an underestimate.
A switch in polarization axis was defined when the dominant polarity patch broke down and a new dominant patch formed in a different quadrant of the AC (see Fig. 4 A).
The coexistence period was defined as the time when multiple patches were first observed until the moment when only one remained and the others completely disassembled.
Multiple patches were not observed in the presence of stable dorsal UNC-6.
In unc-6 and madd-2; unc-6 animals, formation rate was defined as the time period when a future dominant F-actin patch was first detected until the peak volume was achieved. In unc-6; Ex[dorsal UNC-6] animals, F-actin patch formation rate was defined as the period when the AC membrane first encountered a new source of UNC-6 until peak F-actin volume was achieved. A trend line was fit to the volume of each F-actin patch during assembly to determine the slope (rate of F-actin formation). No significant difference in F-action formation rate was observed between unc-6(ev400) and unc-6(ev400); Ex[dorsal UNC-6] (P > 0.1, Student’s t test).
No disassembly was observed with stable dorsal UNC-6.
No significant differences were observed between unc-6(ev400), unc-6(ev400); Ex[dorsal UNC-6], and madd-2(ok2226); unc-6(ev400) (P > 0.1, Student’s t test).
Relative to unc-6; Ex[dorsal UNC-6] (P < 0.001, Student’s t test).
Relative to unc-6 (P < 0.001, Student’s t test).
Relative to unc-6 (P < 0.05, Student’s t test).