Fig. 1

Morphological and transcriptomic comparison of adult, fetal and ESC-tenocytes. a Haematoxylin and eosin (H&E) and Picro Sirius Red staining of adult, fetal and ESC-derived 3D constructs. All cell types show similar collagen fibre alignment and collagen content within the constructs after 14 days of culture. Scale bar for H&E = 0.5 mm. Scale bar for Picro Sirius Red = 250 μm. Images shown are representative of three biological repeats. Under light microscopy, all collagen fibres are red following Picro Sirius Red staining, under polarised microscopy collagen type I fibres have yellow-orange birefringence and collagen type III fibres have green birefringence. b Principle component analysis of gene expression data profiling three biological lines of 3D cultured adult, fetal and ESC-tenocytes. c Matrix of up (green) and down (red) regulated genes for each of the pairwise comparisons. Values represent the number of up- and downregulated genes based on an adjusted p value of < 0.01 and a Log2FC of ± 2. d Boxplots of gene expression of cartilage, tendon and bone markers in adult (teal), fetal (orange) and ESC-tenocytes (yellow). Y-axis shows the gene expression in terms of the log normalised counts. Significant differences are depicted by an asterisk (*) with black asterisks representing a significant difference between the ESC-tenocytes and both the adult and fetal tenocytes, blue asterisks representing a significant difference between the ESC-tenocytes and adult tenocytes only, green asterisks representing a significant difference between the adult tenocytes and both the ESC and fetal tenocytes and purple asterisks representing a significant difference between all three groups