Undergraduate and graduate mathematics teacher education frameworks must ensure professional development of two groups of practitioners within the community of mathematics educators, namely pre-service and in-service mathematics teachers. The relationship between them serves as an example of connection theory and practice in mathematics teacher education. The theory--in the form of models of teachers' interactions and teachers' flexibility--- emerges from careful analysis of in-service teacher dialogue with their students, colleagues, and mentors. It is implemented in practice with pre-service teachers in order to raise the quality of their discourse about teaching. This implementation sheds new light on the role and function of the proposed models.