The aim of the study was to identify initial meanings of the concept of the gene among 50 students from the career training of teachers of biology at the University Pedagogical Experimental Libertador (UPEL), Pedagogical Institute of Caracas, who enrolled in Cell Biology (BC) and General Genetics (GG), as well as those built from a didactic intervention that formed part of Participatory Action Research (PAR). The work is based on the Theory of Meaningful Learning of Ausubel, on the principles of critical meaningful learning facilitators of Moreira, and on elements of the educational act of Novak. To investigate the evolution of meaning of this concept were used: questionnaires, interviews, maps and graphic representations of concepts developed by students. The data analysis provides a differentiated evolution of the meaning of the gene in the students, which corresponds to the didactic intervention and teachers, actions in both courses. It shows the importance of organizing the teaching in a potentially meaningful way to reflect on the content and learning, so that abstract concepts such as gene, must be presented with a critical and reflexive epistemology.