FIGURE 6

FIGURE 6

Transcriptional landscape of the segmentation clock. (A) A simplified schematic of the complex regulatory landscape underlying the mouse and zebrafish segmentation clocks. (B) “Core” and “Peripheral” bHLH genes and Lfng, amongst many others, occupy this regulatory landscape. Based on mutant phenotypes, these clock genes regulate the segmentation clock to varying degrees. Zebrafish consists of many more her/hey genes as a part of its segmentation clock, as compared to mouse or chick, plausibly making the zebrafish clock more robust to genetic or environmental perturbations compared to other species. Finally, we know very little about similar core vs. peripheral clock genes in other species including higher vertebrates like humans, resulting in a knowledge gap that needs to be studied to fully understand this biological clock.