Fig. 2
Merkel cells originate from SOX9-expressing hair follicle cells during embryogenesis. a Experimental design for Sox9-CreER; mT/mG and Lhx2-CreER; tdTomato lineage tracing. b Sox9-CreER; mT/mG lineage tracing. SOX9-traced cells are GFP(+) (green). KRT8(+) Merkel cells are stained in red. Right side panels show zoom in images. White arrows are pointing to Merkel cells. Note the overlap between SOX9 progenies and KRT8 staining. c Quantification of Merkel cells positive for KRT8 and GFP in Sox9-CreER; mT/mG skin sections at P0. n = 4. Data are presented as a percentage of the total number of cells quantified. Bar graph shows the percentage of KRT8(+) cells which are co-labelled with GFP (blue) or not co-labelled with GFP (orange). d Lhx2-CreER; tdTomato lineage tracing. LHX2-traced cells are tdTOMATO(+) (green). KRT8(+) Merkel cells are stained in red. Right side panels show zoom in images. White arrows are pointing to Merkel cells. e Quantification of Merkel cells positive for KRT8 and tdTOMATO in Lhx2-CreER; tdTomato skin sections at P0. n = 4. Data are presented as a percentage of the total number of cells quantified. Bar graph shows the percentage of KRT8(+) cells which are co-labelled with tdTOMATO (blue) or not co-labelled with tdTOMATO (orange). Scale = 50 µm in b and d
