In situ hybridization analysis of Sox11, Pcdh8, Lepre1 and Trpv4 in embryonic mouse hindlimbs. Antisense probes were used to determine the level and distribution of mRNA for each gene. Expression of Sox11 is widespread throughout the limb bud and somites (arrowhead) at E11.5 but declines in level by E12.5 and becomes undetectable by E13.5. Pcdh8 is expressed within the pre-condensations of the tibia and fibula (arrowheads) at E11.5 but is downregulated by the condensation phase at E12.5. At this stage expression is detected in the tissue surrounding the femoral condensation (arrowhead) but declines to background levels by E13.5. Leprecan1 is not detectable at E11.5 but becomes visible in the femoral condensation at E12.5 (arrowhead) and is upregulated within the tibia and fibula at E13.5 (arrowheads). Trpv4 is not detectable within the limb buds at E11.5 or E12.5 but is strongly upregulated in the tibia and fibula at E13.5 (arrowheads). Distal is to the left in all images.