The demographic changes in Greek schools underline the need for reconsidering the way in which migrant pupils move from their everyday culture into the culture of school science (a process known as "cultural border crossing"). Migrant pupils might face difficulties when they attempt to transcend cultural borders and this may influence their progress in science as well as the construction of suitable academic identities as a means of promoting scientific literacy. In the research we present in this paper, adopting the socioculturally driven thesis that learning can be viewed and studied as a meaning-making, collaborative inquiry process, we implemented an action research program (school year 2008-2009) in cooperation with two teachers, in a primary school of Athens with 85% migrant pupils. We examined whether the two teachers, who became gradually acquainted with cross-cultural pedagogy during the project, act towards accommodating the crossing of cultural borders by implementing a variety of inclusive strategies in science teaching. Our findings reveal that both teachers utilized suitable cross-border strategies (strategies concerning the establishment of a collaborative inquiry learning environment, and strategies that were in accordance with a cross-border pedagogy) to help students cross smoothly from their "world" to the "world of science". A crucial key to the teachers' expertise was their previous participation in collaborative action research (school years 2004-2006), in which they analyzed their own discourse practices during science lessons in order to establish more collaborative inquiry environments.