Figure 3. Distribution of germinal and somatic Mu insertions in Mu-seq grid samples.

The bar graph shows the numbers germinal and putative somatic insertion sites detected in each of the 48 grid samples. The class of uniquely assigned germinal insertions and two classes of putative somatic insertions are described in Table 3. Whereas, the germinal insertions (blue bars) are distributed uniformly among the 48 samples, insertions detected in a single axis (red bars) and insertions with low read counts (green bars) are located predominantly in a few samples. The data are consistent with presence of at least 3 Mu-active lines in the grid indicating that our genetic screen for loss of Mu activity based on the bz1-mum9 marker fails at a frequency of about 1% (see text). For clarity, labels of the even numbered axis samples are not shown.