The Lunatic fringe (LFNG) gene shows oscillatory expression in paraxial mesoderm during somitogenesis. WNT signaling activates transcription of LFNG via binding of LEF1:CTNNB1 (LEF1:beta-catenin) to the promoter of the LFNG gene (inferred from mouse homologs). Mesogenin (MSGN1), which is regulated by Notch, also binds the LFNG promoter and activates transcription (inferred from mouse homologs). Hairy and enhancer of split 7 (HES7) directly represses LFNG expression (inferred from mouse homologs in Bessho et al. 2003). HES7 represses its own expression and is therefore expressed in an oscillatory manner (inferred from mouse homologs in Bessho et al. 2003). LFNG represses NOTCH signaling through an uncharacterized mechanism to produce cyclic NOTCH signaling (inferred from chicken embryos in Dale et al. 2003), LFNG expression regulated by both HES7 and NOTCH is therefore also oscillatory (inferred from mouse homologs).
LFNG encodes a glycotransferase that glycosylates NOTCH1 and normally enhances NOTCH signaling. LFNG repression of NOTCH signaling may be indirect, perhaps by modulating the activity of the NOTCH antagonist DLL3, which is also glycosylated by LFNG (inferred from mouse homologs in Bochter et al. 2022).