The psychological literature on the development of gestures during the first year of life has been limited. It has mainly focused on the development of pointing at around 11 months of age, considering it "the" gesture that allows triadic interactions. However, recent studies have argued for the importance of earlier ostensive gestures (showing and giving), not only as precursors of pointing, but also as important gestures for early cognitive and communicative development. These studies have also emphasized the mediating role of materiality and of others (adults and peers) in communicative acts, especially in pre-verbal interactions. This paper reports a longitudinal study of first-year infants in an Infant School classroom in Madrid. Through a microgenetic analysis both infants' gestures and teachers' educational actions related to gesture development were investigated. The results highlight (1) the central role of the teacher in the birth and configuration of infants' gestural repertoire; and (2) materiality as a configurative aspect of communicative interactions during this period as infants communicate not only "about" objects but "through" them. Among the types of gestures observed, self-directed gestures predominated, especially ostensive gestures, these being related to early self-regulation processes. Gesture development could be understood as a process of progressive distancing of the infant from or between the material world and himself/herself. In this process, the teacher can encourage, redirect, and structure the infant's productions through adjustment of their educational activity.