Collaboration between mathematicians and mathematics educators may provide a means of improving the quality of pre-service teacher education for prospective teachers of mathematics. Some preliminary findings of a project that investigates this type of interdisciplinary collaboration, both within and across institutions, are reported on in this paper. Interviews were conducted with selected participants to identify the nature of the boundary encounters and brokering involved between disciplinary communities in order to create new practices and transfer these practices to a new institutional context. [This work was funded by the Australian Government Office for Learning and Teaching (grant #MS13-3174).]