Fig. 1

IGF1R and INSR in midgestation mouse heart. a Western blot analysis of IGF1R and INSR protein at the indicated developmental time points. The mature receptor proteins and the larger precursors prior to proteolytic cleavage are both visualized. b PCR amplification of Insr mRNA to detect the A and B transcript isoforms. c Quantitation of the Insr-A/Insr-B ratio based on amplification such as shown in panel B; value is mean ± SEM