Figure 1.

Notch3 is expressed early in thymocyte differentiation. (A) Gene expression as determined by microarray (Affymetrix U74Av2), where the global median (MAS5) is equal to 500. Only data for high-confidence probesets (at) are shown. Expression was statistically significant (MAS 5 detection call of Present) for all genes at all stages except for Hes1 in DP cells, as indicated by an asterisk. Expression of most Notch-related genes, including Notch3, peaks at the DN3 stage. (B) mAb staining of wild-type (solid line) or Notch3-mutant (dashed line) thymocytes; protein expression directly correlates with gene expression data, with the highest levels of expression on DN3 cells. Filled histograms represent isotype-matched control Ab staining on wild-type cells.