A simplified and defined serum-free medium for cultivating fat across species.

Cultivated meat is a promising technology with the potential to mitigate the ethical and environmental issues associated with traditional meat. Fat plays a key role in the meat flavor; therefore, development of suitable adipogenic protocols for livestock is essential. The traditional adipogenic cocktail containing IBMX, dexamethasone, insulin and rosiglitazone is not food-compatible. Here, we demonstrate that of the four inducers only insulin and rosiglitazone are necessary in both serum-free (DMAD) and serum-containing media, with DMAD outperforming FBS. Two glucocorticoid receptor activators, progesterone and hydrocortisone, found in DMAD and FBS, affect differentiation homogeneity, without playing an essential role in activating adipogenic genes. Importantly, this protocol leads to mature adipocytes in 3D culture. This was demonstrated in both media types and in four species: ruminant and monogastric. We therefore propose a simplified one-step adipogenic protocol which, given the replacement of rosiglitazone by a food-compatible PPARγ agonist, is suitable for making cultivated fat.

Muscle-derived fibro-adipogenic progenitor cells for production of cultured bovine adipose tissue.

Cultured meat is an emergent technology with the potential for significant environmental and animal welfare benefits. Accurate mimicry of traditional meat requires fat tissue; a key contributor to both the flavour and texture of meat. Here, we show that fibro-adipogenic progenitor cells (FAPs) are present in bovine muscle, and are transcriptionally and immunophenotypically distinct from satellite cells. These two cell types can be purified from a single muscle sample using a simple fluorescence-activated cell sorting (FACS) strategy. FAPs demonstrate high levels of adipogenic potential, as measured by gene expression changes and lipid accumulation, and can be proliferated for a large number of population doublings, demonstrating their suitability for a scalable cultured meat production process. Crucially, FAPs reach a mature level of adipogenic differentiation in three-dimensional, edible hydrogels. The resultant tissue accurately mimics traditional beef fat in terms of lipid profile and taste, and FAPs thus represent a promising candidate cell type for the production of cultured fat.