Fig. 3. Differential expression of genes during capillary morphogenesis as determined by reverse transcriptase-PCR and northern blot analyses. Total RNA was prepared from EC cultures at 0, 8, 24 and 48 hours of culture. The RNA was reverse transcribed and PCR was performed using gene-specific primer sets (left panel). Control G3PDH is shown to indicate its stable expression and that equal loading occurred throughout the lanes. Selected genes were analyzed for expression using northern blot analysis (right panel). 3 µg of total RNA was loaded per lane for each time point and blots were probed with ³²P-labelled cDNAs. In the upper panels, the upper arrow indicates the position of the 28S rRNA subunit, whereas the lower arrow indicates the position of the 18S rRNA subunit. The lower panels show just the area of the blot with the hybridizing band. The G3PDH blot indicates equal loading of RNA and stable expression of G3PDH mRNA during the time course.