This study focuses on the potential of university mathematics courses to advance teachers' knowledge regarding an important component of knowledge about the nature of mathematics as a scientific discipline, namely the mutual contribution between mathematics and various fields: mathematics contributes to solving problems in different fields, and different fields contribute to the development of mathematics by raising new mathematical questions and motivating the development of new concepts, methods and research areas. The study investigates (1) what teachers may learn about the nature of the mutual contribution in an academic program that includes university level mathematics courses that offer teachers ample opportunities to learn contemporary and historical mathematical modeling and applications, and (2) what mathematicians, who teach in this program, want to teach teachers about the nature of the mutual contribution. The main data sources included interviews with five mathematicians and 14 secondary school teachers. The results indicate that the mathematicians viewed the mutual contribution between mathematics and other fields as an important component of teachers' knowledge which they wished to advance, whereas the teachers reported only on considerably advancing their knowledge and appreciation regarding one direction: the contribution of mathematics to other fields. Interpretations of the results and future avenues to address this issue are discussed.