Figure 2From: The chick somitogenesis oscillator is arrested before all paraxial mesoderm is segmented into somitesTime course of somite number during chick somitogenesis. Extension of the somite formation period. (A) Graph plotting increasing time intervals along the x axis and increasing number of somites and the corresponding HH stage of chick development along the y axis. The red line is a theoretical line showing the progression if the speed of somitogenesis were to remain constant at 90 minutes throughout development. Each blue dot corresponds to an individual sample/embryo. The blue line is a best fit line. Dotted green line demarcates the average final number of somites. (B-G) Fix and culture analysis using the half embryo system using the caudal region of a chick embryo. Left half samples were immediately fixed whereas right half samples were cultured in vitro for different periods of time and then the expression of c-Lfng was analysed in the two halves by in situ hybridisation. (B) HH stage 20 and (C) stage 23 samples cultured for 90 minutes. (D-G) HH stage 23 samples were cultured for (D) 60 minutes, (E) 90 minutes, (F) 120 minutes and (G) 150 minutes.Back to article page