Fig. 4: Cells expressing Gpr125 on leading tips of branches during pregnancy are unipotent basal progenitors.
From: Gpr125 is a unifying hallmark of multiple mammary progenitors coupled to tumor latency
a UMAP plot and violin plot (b) showing Adgra3 expression restricted to the mammary basal populations. c Violin plot showing expression levels at days of gestation (dG) as indicated in Basal 2 and Basal G cell types44. d–f X-gal (blue) stained mammary whole mounts from pregnant mice Scale bar = 500 µm (n = 4 mice/stage) showing Gpr125-β-gal expression at d sites of emerging side-branches at 12.5 days of pregnancy (p12.5), e tips of elongating side-branches at p13.5, and f in ducts but not alveoli at p15.5. g, h X-gal (blue) stained sections of a permanent duct and side branch with immunolocalization (brown) of basal marker p63 and K14. Scale bar = 20 µm (n = 2 mice). i–l X-gal (blue) stained sections counterstained with NFR. Boxed insets are higher magnification of regions indicated by arrows (n = 2 mice/stage). m Schematic illustrating strategy to trace the lineage of cells that express Gpr125 during early pregnancy by delivering Tam at p14.5 and harvesting glands at p20.5 and L6 mice. n tdT+ SMA+(red/green) cells were found in ducts and alveoli at p20.5 and at birth (o). p Fully differentiated tdT+ cells were devoid of luminal Ecad marker (green) at L6. Scale bar = 50 µm. tdT = red, tdT+ cells; DAPI = blue, nuclear staining. One gland from each of the five mice was analyzed.
