Fig. 4.
LdBCs reconstitute mammary glands upon transplantation. a Illustration of OVX, labeling, hormonal stimulation and transplantation strategies using K8-CreERT2;R26-mTmG mice. b 2 weeks post TAM labeling and hormone stimulation, the mammary cells were FACS isolated. 3 groups, normal basal (Lin−, CD24+, CD29hi, tdTom+), LdBC (Lin−, CD24+, CD29hi, GFP+), and luminal (Lin−, CD24+, CD29low, GFP+) were transplanted to cleared fad pads of Nude recipients in limiting dilution as indicated. The degree of outgrowth was evaluated based on the occupancy of mammary fat pad. The representative images were shown on the right. Repopulating frequency in each group is indicated. Data were pooled from three independent experiments. *** P < 0.01, ns P > 0.1, Scale bars, 1 mm. c The outgrowths derived from LdBC (GFP+) were analyzed by immunostaining, showing normal basal (K14+) and luminal (K8+) composition. Scale bars, 10 μm. d, e FACS analysis of the outgrowths derived from normal basal cells (tdTom+) (d) and the outgrowths derived from LdBC (GFP+) (e) showing LdBC-derived outgrowths have normal basal and luminal composition. f LdBC-derived outgrowths (GFP+) were analyzed by immunostaining, showing ERα-expressing basal cells (ERα+ SMA+) (arrows). Scale bars, 10 μm. g Three groups, basal cells isolated from normal basal-derived outgrowths (Lin−, CD24+, CD29hi, tdTom+), basal cells isolated from LdBC-derived outgrowths (Lin−, CD24+, CD29hi, GFP+), and luminal cells isolated from LdBC-derived outgrowths (Lin−, CD24+, CD29low, GFP+) were transplanted to cleared fad pads of Nude recipients as indicated. Hormone stimulation with E2 + Pg pellets was also added to the latter two groups. The degree of outgrowth was evaluated based on the occupancy of mammary fat pad. Repopulating frequency in each group is indicated. Data were pooled from two independent experiments