A) Expression of known ‘tendon’ transcription factors, B) TGFβ and C) ECM genes measured with RNA-seq.

<p>Genes associated with tendon development are not significantly differentially expressed at postnatal stages (A). Analysis of TGFβ ligands and receptors shows that <i>Tgfb1</i> is differentially upregulated at P7 only, <i>Tgfbr1</i> is intermittently differentially expressed, and <i>Tgfbr3</i> is differentially upregulated from P0 to P35 (B). Expression of ECM related genes are significantly differentially expressed in unique directions during postnatal stages with <i>Dcn</i> and <i>Fmod</i> increasing gradually over time, <i>Col2a1</i>, <i>Col14a1</i>, <i>Col3a1</i>, and <i>Tnmd</i> decreasing over time, <i>Col1a1</i> and <i>Col1a2</i> peak in expression at P14, and <i>Bgn</i> is expressed at higher levels from P0-P14 after which its levels decrease (C). Kruskal-Wallis rank sum test followed by a Dunn test with Benjamini-Hochberg correction were used to test for specific differences among pairs of time points.</p> <p>(TIF)</p>