Figure 2.

TSL expression levels are constant throughout the cell cycle in synchronized cells. A, Top, Suspension culture cells were incubated with aphidicolin for 24 h, and then washed extensively and fresh culture medium added. RNA was isolated from cells at time points (h) following release from aphidicolin block and subjected to northern-blot analysis. Total RNA (20 μg) was loaded per lane, and the blot was hybridized with a histone H4 cDNA probe. Bottom, The same blot was stripped and hybridized with 18S rRNA sequences as a control for RNA loading (after hybridizing with TSL cDNA in C). B, Samples from aphidicolin synchronized cell populations, as in A, were analyzed for mitotic index. C, Top, Northern-blot analysis of Arabidopsis TSL across the cell cycle. The same blot after stripping as in A was hybridized with a TSL cDNA probe. Bottom, TSL protein accumulation in synchronized Arabidopsis cell suspension culture. Total protein extract (300 μg) from samples of aphidicolin released cells collected at 2-h time intervals was run on a 10% SDS-polyacrylamide gel and then analyzed by western-blot analysis with α-TSL peptide antibody.