Patterns of gene expression in hand digit I (HDI), hand digits II-V (HDII-V), and all five foot digits (Foot). To validate DGE-tag profiling, expression of 14 genes, exhibiting differences in expression among the M. ricketti libraries, were examined in two independent H. armiger embryos using RT-qPCR. (A) Meis2; (B) Hoxd10; (C) Tbx3; (D) Tbx15; (E) Bmp3; (F) Rgmb; (G) Twist1; (H) Hoxa1; (I) Tmeff2; (J) Enpp2; (K) Krt17; (L) Tbx4; (M) Acta1; (N) Tnnc2. The overall pattern and significance of gene expression differences among the samples were concordant using the distinct methods and taxa. The fold changes in expression among samples were reduced in the RT-qPCR in several cases; however this difference is not surprising given the difference in sensitivity of gene detection in the two methods. The y-axis indicates fold change in expression between the samples - HDI, HDII-V, and Foot - using the results from RT-qPCR (dotted bars) and DGE-tag profiling (grey bars) independently. Significance of pairwise comparisons (HDI vs. HDII-V and Foot vs. HDII-V) are indicated by the asterisks between the bars. *, p < 0.05; **, p < 0.01; ***, p < 0.001.