Control of Embryonic Brown Adipocyte Development by GATA6 I

Brown adipose tissue (BAT) is a thermogenic organ that protects animals against hypothermia and obesity. BAT derives from the multipotent paraxial mesoderm; however, the identity of embryonic brown fat progenitor cells and regulators of adipogenic commitment are unclear. Here, we performed single cell gene expression analyses of mesenchymal cells during mouse embryogenesis with a focus on BAT development. Live single cells from E10.5-E15.5 mouse embryos were enriched for mesenchymal, dermomyotome (DM) and brown adipose lineage cells as follows: (i) E11.5 and E12.5 DM and mesenchymal cells based on cell surface expression of PDGFRa and/or LRIG1 [30% PDGFRa+, LRIG1(-) cells; 25% PDGFRa(-), LRIG1+ cells, 30% PDGFRa+, LRIG1+ cells, 15% PDGFRa(-), LRIG1(-) cells]. (ii) E13.5-E15.5 fibroblasts through selection of PDGFRa+ cells [75% PDGFRa+; 25% PDGFRa(-)]. (iii) E10.5, E14.5, and E15.5 brown adipose lineage cells based on expression of Early B Cell Factor-2 (Ebf2)-GFP [75% Ebf2-GFP+; 25% Ebf2-GFP(-)].棕色脂肪组织（brown adipose tissue, BAT）是一类具备产热功能的器官，可帮助动物抵御低体温与肥胖。BAT起源于多能轴旁中胚层；然而，目前胚胎棕色脂肪祖细胞的身份以及成脂定向调控因子仍不明确。本研究针对小鼠胚胎发生过程中的间充质细胞开展单细胞基因表达分析，重点聚焦BAT的发育进程。我们通过如下方式富集了E10.5至E15.5阶段小鼠胚胎的活单细胞，涵盖间充质、生皮肌节（dermomyotome, DM）及棕色脂肪谱系细胞：(i) 针对E11.5与E12.5阶段的生皮肌节及间充质细胞，基于细胞表面血小板衍生生长因子受体α（PDGFRα）和/或亮氨酸重复序列免疫球蛋白样蛋白1（LRIG1）的表达进行分选：其中30%为PDGFRα阳性、LRIG1阴性细胞，25%为PDGFRα阴性、LRIG1阳性细胞，30%为PDGFRα阳性、LRIG1阳性细胞，15%为PDGFRα阴性、LRIG1阴性细胞。(ii) 针对E13.5至E15.5阶段的成纤维细胞，通过分选PDGFRα阳性细胞完成富集（75%为PDGFRα阳性细胞，25%为PDGFRα阴性细胞）。(iii) 针对E10.5、E14.5及E15.5阶段的棕色脂肪谱系细胞，基于早期B细胞因子2-绿色荧光蛋白（Early B Cell Factor-2, Ebf2-GFP）的表达进行分选：其中75%为Ebf2-GFP阳性细胞，25%为Ebf2-GFP阴性细胞。