Fig. 7. Expression patterns of the rps4, car1 and csA mRNAs during early development in Ax-2 cells and cells. Cells were harvested at the growth phase (V), washed twice in BSS and shaken for the indicated times (hours) at 22°C. Total RNAs were prepared according to the method of Nellen et al. (Nellen et al., 1987). Northern hybridization was performed using the RI (Amersham), as previously described (Hirose et al., 2000). As probes for detection of the three kinds of mRNAs, PCR products obtained by amplification of the respective cDNA clones, using M13-20 and M13R primers, was used. The lower panel shows for each lane the amount of ribosomal 17S and 26S RNA stained with EtBr.