spectrum of this gene is shown in Figure 2.38. Figure 2.39 shows

poson insertion spectrum for the gene dnaN (FTT_0002), for

0 insertions were distributed at 18 sites.

The transposon insertion spectrum of the gene dnaN (FTT_0002) in the first

the Francisella Tularensis species.

e properties of the transposon statistics

38 of 1,556 genes in the first replicate of the Francisella

is species had no transposon insertions. These genes were

y essential. The rest 1,518 genes had varying insertion

ons in their gene bodies. The essentiality analysis of these 1,518

s thus the main objective of essential gene discovery.

ultimate goal of the gene essentiality pattern discovery is to

whether a transposon statistic (either the insertion statistic or the

tic) of a transposon sequencing data followed a bimodal density.

density of a transposon statistic can be bimodal, it is thus possible

mine a proper threshold to separate essential genes from non-

genes.

e 2.40(a) shows the density estimated based on the logarithm-

med insertion statistic and Figure 2.40(b) shows the density

d based on the logarithm-transformed site statistic for the first

of the Francisella Tularensis species. However, neither had a

modality. Therefore, it was not very easy to determine an optimal

to partition these genes into two clusters, hence to discover

genes based on this type of densities. This means that some

statistic must be considered for a better gene essentiality analysis.