Table 1 Influence of ectopic A-lattice seams on MT dynamics.

	Growth (mean±s.e.m. ( n ) nm s⁻¹)	Shrinkage (mean±s.e.m. ( n ) nm s⁻¹)	Catastrophe (frequency±CL ( n ) min⁻¹)	Growth %	Shrinkage %	Dithering %
Plus end
B-lattice	5.86±0.19 (85)	158.5±6.0 (77)	0.25±0.20/0.29 (135)	92.1	1.9	6.0
A-lattice (5 μM Mal3FL seed)	6.22±0.15 (158)	156.5±4.48 (124)	0.33±0.29/0.38 (243)	90.5	2.4	7.1
A-lattice (50 μM Mal3FL seed)	5.27±0.38 (27)	139.3±10.7 (15)	0.35±0.27/0.46 (54)	74.7	1.8	23.5
Minus end
B-lattice	3.62±0.16 (25)	90.9±10.8 (7)	0.040±0.03/0.07 (25)	99.2	0.6	0.2
A-lattice (5 μM Mal3FL seed)	4.11±0.11 (57)	140.6±10.2 (23)	0.080±0.06/0.10 (54)	97.4	1.1	1.5
A-lattice (50 μM Mal3FL seed)	3.55±0.33 (10)	130±20.1 (6)	0.12±0.07/0.19 (19)	98.3	1.7	0.0

MT dynamics parameters were determined from plots of MT length against time automatically generated from kymographs of dynamic (GTP/GDP) MTs (Fig. 2). Mean rates of growth and shrinkage were compared by one-way ANOVA and Tukey post test. The means of plus end growth rates (F (2, 267)=3.40, P=0.035), minus-end growth rates (F (2, 89)=3.82, P=0.026) and minus-end shrinkage rates (F (2, 29)=3.605, P=0.04) were significantly different, whilst plus end MT shrinkage rates were not (F (2, 213)=0.93, P=0.40). Using Tukey post test for pair-wise comparisons the differences in mean growth were significant (at P<0.05) between the two A-lattice seeds (5 μM Mal3FL was 1.2 × faster growth than 50 μM), but not between the A-lattice and B-lattice single-seam seeds. Minus-end shrinkage with A-lattice 5 μM Mal3FL seeds was significantly faster than from the B-lattice seeds. The Tukey test found no pair-wise significant differences in the minus-end growth rates at P<0.05. Total observation times were 598.4, 811.4 and 203.7 min at the plus end and 566.7, 703.8 and 158.5 min at the minus ends for B-lattice single-seam and A-lattice-enriched assembled from 5 and 50 μM Mal3FL seeds respectively. CL, Poison confidence limits, P=0.05.

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