A CR twistor space of a G2G2-manifold

Let M   be a G2G2-manifold. We consider an almost CR-structure on the sphere bundle of unit tangent vectors on M, called the CR twistor space. This CR-structure is integrable if and only if M   is a holonomy G2G2-manifold. We interpret G2G2-instanton bundles as CR-holomorphic bundles on its twistor space.