Fig. 7

Osr1 is required for muscle connective tissue ECM gene expression. a Bar graph plot of genes selected from all DE genes by their expression associated with muscle connective tissue; most of the genes belong to the downregulated cluster in (Fig. 6c). b Confirmation of downregulation of selected MCT-ECM genes in E11.5 and E13.5 Osr1 deficient cells by RT-qPCR (n = 4). c Immunolabelling for MyHC and COL6 shows reduced abundance of COL6 in Osr1 mutants. d Transduction of E13.5 MEFs with lentiviral particles causes mild overexpression of Osr1. e Lentiviral overexpression of Osr1 causes upregulation of Col6a1, Col6a3 and Lum genes. f Chromatin immunoprecipitation of putative Osr1 binding sites at the Col6a1 and Col6a3 loci. Above: schematic representation of the loci; positions of Osr1 binding sites and PCR primers relative to exon 1 of the Col6a1 and Col6a3 genes are indicated. Below: representative gel pictures of ChIP vs. input are shown left, confirmation of binding site pulldown via RT-qPCR (n = 3) are shown right. Bs: putative binding site, No Bs: control region. Size marker: 100 base pair ladder; band sizes are indicated in base pairs. Error bars represent log2 fold change standard error (ifcSE) estimated by DESeq2 in a and s.e.m. in (b, d, e, f). T-test: *=p < 0.05; **=p < 0.01; ***=p < 0.001. N-numbers indicate biological replicates, i.e. samples from different specimen in b or independent assays in d, e, f