Figure 1. Experimental approach to examine the impact of crosslinking on anomalous transport in cytoskeleton networks.

(A) Schematic of the different crosslinking motifs created in actin-microtubule networks: no crosslinkers (None), actin crosslinked to actin (A-A), microtubules crosslinked to microtubules (M-M), both actin-actin and microtubule-microtubule crosslinking (A-A/M-M), and actin crosslinked to microtubules (A-M). Biotinylated actin filaments and/or microtubules are crosslinked with NeutrAvidin to achieve the different motifs. (B) Videos of diffusing 1 μm fluorescent microspheres are collected and analyzed using single-particle tracking (SPT) (C) and differential dynamic microscopy (DDM) (D). (C) For SPT, the mean squared displacement (MSD) is plotted versus lag time ($\Delta t$) and fit to the power-law function $\mathrm{M}\mathrm{S}\mathrm{D}\propto (\Delta {t)}^{\alpha }$ that describes anomalous diffusion. (D) For DDM, intermediate scattering functions are generated and fit to $f\left(q,\Delta t\right)=\left(1-C\left(q\right)\right)\exp \left[-{\left(\frac{\Delta t}{\tau \left(q\right)}\right)}^{\gamma \left(q\right)}\right]+C\left(q\right)$ to extract the decay times $\tau \left(q\right)$, stretching exponents $\gamma \left(q\right)$, and nonergodicity parameters $C\left(q\right)$ for each condition. Data shown in (C) and (D) are for particles diffusing in the network without crosslinking (None).