Timing Embryo Segmentation: Dynamics and Regulatory Mechanisms of the Vertebrate Segmentation Clock

Table 2

Mutations in key genes belonging to the Notch, Wnt, and Fgf signaling pathways and subsequent phenotype observed in the expression of genes involved either in the molecular clock or in the wavefront of differentiation. Only mutations bringing insight into the putative cross-talk between pathways are indicated.

Pathway	Mutated gene	Effects in gene expression	References
Notch	dll1 null	↻ axin2; ✓ fgf8, wnt3a	[35]
	hes7 null	↻ axin2, snail1, dusp6, spry1; ∅lfng, nrarp, dusp4, nkd1	[73]; [70]; [68]
	Notch overexpression	↻ snail2	[71]
	psen1/psen2 null	∅axin2, snail1, dusp6, spry2	[73]
	Rbpjk null	↻ spry2, dusp6, axin2, hes7, snail1; ∅lfng	[63]; [73]; [71]
Wnt	Sustained axin2	∅lfng	[35]
	𝛽-catenin Gof	↑dusp6, spry2	[40]
	Truncated lef	∅lfng; ↓dll1, notch	[74]
	wnt3a mutant vt	∅snail1, lfng, axin2, nkd1; ↓fgf8, dll1, notch	[71]; [35]; [68]
Fgf	Conditional fgfr1	∅lfng, hes7, spry2, axin2, snail1	[75]; [70]
	snail2 overexpression	∅lfng	[71]

↻: normal oscillations; ✓: normal expression; ∅: disrupted oscillations; ↑: increased expression; ↓: decreased expression.