Fig. 3Size factor normalization for the RNA-seq data. The box plot on the right shows the distribution of gene
expression values in each sample. The box plot is a standardized way of displaying the distribution of a set of
data points. The central rectangle spans from the first quartile to the third quartile (the 25th to 75th
percentiles), and this distance is termed interquartile range (IQR). A segment inside the rectangle shows
the median, and whiskers stretching outside the box show the 1.5*IQR from the lower and upper quartiles.
Data points beyond the end of the whiskers are called “outlier points” and are plotted individually
Fig. 4Hierarchical clustering for all samples. The replicate embryonic and adult samples cluster together,
respectively
174 Chao Zhang et al.