First two principal components of PCA trained on the expression profiles of 6,455 developmental marker genes. Several published gonadal microarray datasets ("test dataset") have then been mapped onto the PCA space (our large panel of wild-type and mutant gonads) (x-axis, PC1; y-axis, PC2; PC units, linear transformations of the rank-normalized gene expression intensities). A) Illustration of the trajectories (arrow-headed lines) corresponding to normal gonadal development in females (circles) and males (diamonds). B) Trajectories of mutant gonads (colored shapes) added to the wild-type panel (i.e., as in A; arrows have the same colors as the corresponding samples).
Garcia-Ortiz et al. BMC Developmental Biology 2009 9:36 doi:10.1186/1471-213X-9-36