qRT-PCR expression patterns for selected genes from the microarray gene expression clusters. The mRNA expression patterns of selected genes from the major gene expression clusters were also measured by qRT-PCR. The expression levels are expressed as mean normalised expression (MNE) values relative to the reference gene, 18S RNA. The corresponding gene expression cluster derived from microarray data is shown in brackets. Fetal samples at 80, 100 and 120 days of development and postnatal samples at 150 d and 230 d of development are shown. The result for each gene shows the mean (n = 3) while the error bar denotes 1 S.D.