Opus itself does not support mouse gestures; however, you can add them to Opus, and any other programs you run, using small tools which are dedicated to this purpose. This has the advantage of making gestures standard and non-conflicting across all applications, as well as giving you the ability to have some gestures which are global to all apps and some which are specific to certain apps.
For more information, including links to some gesture programs recommended by other Opus uses, please see this tutorial by forum member Slowave: