In this article, we examine some properties of the interface between meaning and knowledge in popularization discourse in the Spanish press aboutthe sequencing of the human genome. After a multidisciplinary account of popularization in terms of text, context and knowledge, we analyze some semantic aspects of 42 texts in El País, focusing especially on denominations, explanations and the description of new objects. Besides the usual metaphors conceptualizing the genome in terms of a code or a book, and sequencing as decodification, we especially found that descriptions of new objects tend to be organized using a limited number of fundamental categories, such as Location, Composition, Size, Quantity, Appearance and Functions. We surmise that these meaning categories correspond to underlying cognitive categories that organize the schematic structure of knowledge about things. Both in the discursive and the epistemic analysis of these texts, we are specifically also interested in the strategies of specialized journalists for the management of knowledge: what knowledge is being presupposed, what knowledge is being ‘reminded’or actualized and what knowledge is expressed and newly constructed.