Fig. 6

Quantitative analysis of the dynamic expression of eve, odd and hh. a-c High magnification images of the growth zone and posterior germband of embryos stained for (a) eve (b) odd and (c) hh. (a’-c′) Gene expression levels in the embryo shown above. For each embryo, we drew a rectangle encompassing the entire imaged region and summed the pixel intensities for each point along the x-axis (posterior to anterior). Comparison of the signal intensity highlights the small differences in the expression profile of these genes in the GZ. The main difference seems to be that while eve is robustly expressed in the posterior GZ and is strongest in the anterior of the posterior GZ, odd is weakly expressed in the posterior GZ, increasing in strength towards the anterior, and peaking only in the first discrete odd stripe in the anterior GZ. The main observation regarding the hh expression profile is the double-peak between the stripe in the anterior GZ and first stripe of the posterior GZ, which are not completely resolved. Only the third hh stripe is completely resolved. d-e 3D plots including a sequence of embryos expressing (d) hh and (e) eve, arranged in sequence by increasing total length of the GZ + abdominal segments. The third thoracic segment (T3) was defined as the zero point of the y-axis of each graph. For eve n = 71 for hh n = 53