Developmental transition of brown adipose tissue from thermogenic to lipogenic phenotype in neonatal goats: insights from single-cell transcriptomics

Brown adipose tissue (BAT) plays a pivotal role in neonatal thermogenesis and adaptation. In newborn goats, BAT is primarily found around the kidneys and undergoes involution during the first month of life. However, the mechanisms driving this change have remained elusive. We constructed a comprehensive transcriptomic dataset of perirenal adipose cells, capturing 54,638 high-quality nuclei across three developmental stages (0, 7, and 14 days post-birth). This dataset enabled the identification of six distinct perirenal adipose cell types based on their gene expression patterns. Our analysis revealed that adipocyte progenitors exhibit high secretory activity. Furthermore, we observed changes in lipid and fatty acid metabolism, as well as in the AMPK and PPAR signaling pathways, over developmental time. These changes are associated with accelerated fat synthesis, characterized by an increasing trend towards fat deposition. This changes arises from an increase in the proportion of adipocyte subpopulations promoting fat deposition, while those favoring thermogenesis decrease. Consequently, within the first 14 days post-birth, we observed a change from brown to white-like adipose tissue. These findings provide insights into the developmental trajectory of BAT and its role in neonatal thermogenesis and fat deposition.