Figure 39.

The ability for coarse-graining varies strongly among the different phenomena studied on the cellular level. (a) So far, the mechanical behavior of cells on shorter timescales is mostly described by phenomenological models. A decent microscopic understanding might already result from models originating from the underlying network level. By comparing to the subcellular level, however, one has to expect that compound and transient networks will be most relevant demanding some adaptation of even lower levels. (b) Cell division involves the interplay of numerous different proteins and includes several internal feedback loops which makes it less accessible to coarse-graining. (c + d) Various model approaches aim at further understanding cell motility. Lamellipodial motion is particularly accessible to coarse-graining and hence attracted most attention from physicists (c). Whereas some models start from the molecular level others further coarse-grain the problem to the network, i.e. the actin gel level. (d) As soon as filopodia or MTs significantly influence the cellular migration, the filament can no longer be ignored.