FIG. 7.

Northern blot analysis of the time course of ScDSP mRNA levels in Skeletonema costatum. (a) Total RNA samples were fractionated on a 0.7% formaldehyde-agarose gel and transferred to a nylon membrane. ScDSP mRNA was detected with the gene-specific DIG-labeled antisense riboprobe. The time points (in days) of sampling are indicated at the top. The numbers (in kilobases) on the left side are the positions of the RNA standards. The smear of ScDSP mRNA was caused by loading too much total RNA into the sample wells. (b) Total RNA integrity was examined by ethidium bromide staining after agarose electrophoresis. The positions of 18S and 28S rRNA are indicated on the left.