High impact information on Hes7

• Expression of the basic helix-loop-helix factor Hes7, an effector of Notch signaling, follows a 2-hour oscillatory cycle controlled by negative feedback; this is proposed to be the molecular basis for the somite segmentation clock [1].
• Instability of Hes7 protein is crucial for the somite segmentation clock [1].
• Spatial comparison revealed that Hes7 and Lunatic fringe (Lfng) transcription occurs in the Hes7 protein-negative domains [2].
• Hes7, a bHLH gene essential for somitogenesis, displays cyclic expression of mRNA in the presomitic mesoderm (PSM) [2].
• Notch signalling molecules, such as the basic helix-loop-helix factors Hes1 and Hes7, periodically change their expression in the presomitic mesoderm, and each cycle of gene expression is associated with somite formation (every two hours in mouse) [3].

Biological context of Hes7

• The mouse Hes7 gene is located next to Aloxe3, which is mapped to a position 37.0 cM from the centromere on chromosome 11 [4].
• This is accompanied by the rostral extension of oscillatory gene expression such as L-fng, Hes7, and Dll1, and the rostrally shifted termination of Raldh2 expression that continues from the anterior embryonic side [5].

Anatomical context of Hes7

• Strikingly, Hes7 is specifically expressed in the presomitic mesoderm in a dynamic manner [4].
• Periodic repression by the bHLH factor Hes7 is an essential mechanism for the somite segmentation clock [2].

Other interactions of Hes7

• These results suggest that the transcription of nkd1 requires Wnt3a, and that its oscillation patterns depend upon the function of Hes7 [6].

References