Fig. 1

Single Blimp1⁺ cells generate sebaceous gland-like structures ex vivo. a Representative image of dorsal skin wholemount extracted from P56 (telogenic)-old B6.Cg-Tg(Prdm1-EYFP)1Mnz/J (denoted Blimp1-YFP) mouse stained for Oil Red O (ORO). Blimp1-YFP⁺ signal (yellow arrows) can be seen at the base of the sebaceous gland (SG) [n = 5 mice]. b Fluorescent-activated cell sorting (FACS) analysis employing Blimp1-YFP reporter mice demonstrating the α6⁺;Sca1^-;Blimp1^-YFP⁺ (Blimp1-YFP⁺) population [n = 5 pooled mice]. c Image stream analysis showing representative brightfield (BF) images of Blimp1-YFP⁺ cells, indicating that these cells display three distinct morphologies: (1) small cells with high circularity, (2) large cells resembling sebocytes, and (3) differentiated keratinocytes. d Schematic diagram representing the process of Blimp1-YFP⁺ cell-derived organoid generation. e Representative images of initial single seeded Blimp1-YFP⁺ cell maintained in 3D culture for a period of 12 days. Scale bar is relative to all images shown for each day. f Single-cell suspension of Blimp1-YFP⁺ cells, supplemented with growth factors, form a large number of organoids after a period of 1 week. g Representative 3D-reconstructed confocal image of an organoid after 10 days in culture stained for actin. Left panel shows an external view of a layer of compact similarly sized cells, while the right panel demonstrates cross-section of large inner cells of varying sizes. All experiments were repeated at least three times with similar results. Organoids were grown from a mix of at least three mice and cultured in three independent biological repeats. Scale bars: 10 μm (c), 20 μm (a, e), 50 μm (g), 100 μm (f, f inset)