Biology Reference
In-Depth Information
FIGURE 20.2
Profiling mRNAs at cell type-specific and developmental stage-specific resolution. (A) Schematic of cell types and (B) developmental
zones profiled. (C) Dominant expression patterns identified among cell populations. (Adapted from
[3]
.)
usually pass through a 'transit amplifying' stage during
which there is rapid cellular proliferation, prior to the onset
of differentiation. In the root, the onset of differentiation
occurs when cells stop dividing and begin to elongate,
a process that can increase their volume over 100-fold.
From the developmental stage-specific expression data,
transcription factors were identified whose expression
peaked at the transition from cell division to elongation
[10]
. Insertional mutations were tested in 50 genes,
resulting in the identification of one mutant with enhanced
