Mutual Repression Enhances the Steepness and Precision of Gene Expression Boundaries
Figure 8
Robustness of the gap-gene expression boundaries to variations in the bcd gene dosage.
(A) Time- and circumference-averaged Hb (, solid lines) and Kni (
, dashed lines) total copy-nymber profiles along the AP axis for various bcd gene dosage factors
and
. Inset: the average occupancy of the promoter states with five bound morphogen molecules as a function of
. (B) Comparison of the boundary position
as a function of
for
to values measured by Houchmanzadeh et al. [5] (black line). The red line shows the simulation results for the system without mutual repression. Note the good agreement between the experimental data and the simulation data of the system with mutual repression. (C) Profiles of the average standard deviation of the total Hb (
, solid lines) and Kni (
, dashed lines) copy number. Inset:
as a function of
. The grey dashed line represents the Poissonian limit. (D) The Hb boundary width
as a function of
and
, the separation between the Hb and Kni boundaries in a system without mutual repression, for the system with (green) and without (red) mutual repression.
is varied by multiplying the Bcd level by
.