Table 1.

Microtubules are not randomly distributed with respect to intrapodia in the P domain

A  Condition	B P domain area (μm2)	C No. MT tips in P domain	D No. intrapodia	E No. MT tips ≤1 μm intrapodium	F p. MT tip ≤1 μm intrapodium (πD/B)	G p. ≥E colocal (1-ΣBin[<E,C])
Cntrl	52	6	2	2	0.12	0.16
Cntrl	52	9	2	1	0.12	0.68
Noc	112	5	3	2	0.08	0.06
Noc	152	8	4	3	0.08	0.03
Taxol	105	1	2	1	0.06	0.06
Taxol	61	1	1	1	0.05	0.05

In six growth cones fixed during the indicated conditions: Cntrl, untreated; Noc, after nocodazole washout; Taxol, after Taxol washin (A), We determined the area of the P domain (B), the number of microtubule (MT) tips in the P domain (C), the number of intrapodia in the P domain (D), the number of microtubule tips within 1 μm of the center of the initiation sites of the intrapodia (E), the probability that any particular microtubule would be found within 1 μm of the center of the initiation sites of the intrapodia (E), the probability that any particular microtubule would be found within 1 μm of an initiation site of any of the intrapodia if microtubules and intrapodia are distributed randomly throughout the P-domain (F) (can be viewed as the proportion of the area [B] occupied by D intrapodia initiation sites), and the probability of observing at least E colocalization events (G). This is determined by evaluating the binomial probability for less than E successes (colocalizations) for C trials (MT endings in the cone) given the probability determined in F for any particular trial (MT) to result in success (colocalization) and subtracting the chances for less than E successes from 1.0.