Testicular development is disrupted in the absence of insulin/IGF signaling.

<p>Expression of key testicular genes such as <i>Sry</i> (A–C), <i>Sox9</i> (D–F), <i>Fgf9</i> (G,H), <i>Amh</i> (I,J), <i>Insl3</i> and <i>p450scc</i> (K,L) was assessed in XY control and XY dko gonads at E11.5, E12.5 or E13.5 using qRT-PCR (A,D,G,I), whole mount <i>in situ</i> hybridization (B,E,H,J,K) or by double immunofluorescence (C,F,L) using sagittal sections, except for the first two panels in C, for which the embryos were cut transversally and arrows point toward genital ridges. XY control and XY dko gonads were immunostained for either SRY (C, in green), the Sertoli-cell marker SOX9 (F, in green), or the Leydig cell marker P450SCC (L, in green), along with E–cadherin (red), which labels germ cells and mesonephric tubules. Note the drastic reduction in <i>Sry</i>, <i>Sox9</i>, <i>Fgf9</i>, <i>Amh</i>, <i>Insl3</i> and <i>p450scc</i> expression and the absence of testis cords in XY dko gonads. REL, relative expression levels. Values are expressed as means ± SEM, **p<0.01, ***p<0.001 vs control.