The structure, function and dynamic behavior of the cytoskeleton can be very different, depending on organism and cell type. Even within one cell the cytoskeleton can change through association with other proteins and the previous history of the network. A multitude of functions can be performed by the cytoskeleton.
The new Courage XT-6 (3.5 net HP) and Courage XT-7 (4.5 net HP) engines will be available on OEM push-mower brands in early 2008. The first two models from Kohler are engineered in the United States with high performance and ease of use in mind.
In summary: Husqvarna, MTD, and Briggs & Stratton make most of the riding mower and lawn tractor brands sold by retailers here in the United States. John Deere still makes all of their lawn tractors and zero-turn mowers. There are around 40 additional manufacturers of zero-turns and specialty mowers. The Zero-Turn market is huge so there is always a new manufacture or three trying to make their mark.