Fig. 1.

Nck1 and Nck2 are expressed in various cell types in the developing mammary gland. A, B Single cell RNA sequencing of Nck1 and Nck2 in all cell types of the murine mammary gland (from Schaum et al. 2018) [17]. A Violin plot of Nck1 gene expression in clustered groups defined as luminal epithelial cells, basal cells, stromal cells, and endothelial cells of the mammary gland. B Violin plot of Nck2 gene expression in clustered groups defined in (A). C, D (C) Dendrogram showing putative identities of 15 distinct mammary epithelial cell clusters following single cell RNA sequencing of nulliparous “NP”, mid gestation “G”, lactation “L”, and post-involution “PI” mammary glands and (D) t-SNE plot of mammary epithelial cell clusters used to overlay with Nck1 (E) and Nck2 (F) expression (from Bach et al. 2017) [18]. E Nck1 gene expression was detectable in all clusters, with highest levels in the myoepithelial C14 cluster. F High levels of Nck2 gene expression were detectable primarily in luminal hormone sensing progenitors C1 and C2 and hormone sensing differentiated C3 and C4 clusters. G ddPCR analysis of Nck1 and Nck2 abundance, normalized to Hprt/Gapdh, in 5, 8 and 12 week old wildtype mouse mammary glands of the indicated genotype (n = 4). * P < 0.05; by Mann–Whitney test performed independently at each of the respective timepoints (5, 8, and 12 weeks)