Table 4.

A simple model for predicting regulatory relationships from temporal and spatial expression patterns

GeneTemporal phaseSpatial expression patternSupporting dataRefsBest candidate upstream activator
pal-1 I16 C, 4 DReporter, antibody, in situ hybridizationEdgar et al., 2001; Hunter and Kenyon, 1996 pal-1
cwn-1 IIC and D muscle, 2 posterior C ectoderm pal-1
C55C2.1IILeft posterior muscle (C and D), unidentified ventral cells pal-1
hnd-1 IIAll muscle (including 8 C muscle, 4 D muscle)Reporter Mathies et al., 2003 pal-1
tbx-8 IIDorsal epidermis, unidentified lateral cells (including 8 C ectoderm)ReporterPocock et al., 2004; Andachi, 2004 pal-1
tbx-9 IIDorsal epidermis, unidentified lateral cells (including 8 C ectoderm)Reporter, in situ hybridizationPocock et al., 2004; Andachi, 2004 pal-1
elt-1 IIAll major epidermisAntibody Page et al., 1997 pal-1
vab-7 III8 C: four posterior muscle, four posterior ectodermReporter, in situ hybridization Ahringer 1996 cwn-1
unc-120 IIIAll muscle (including 8 C muscle, 4 D muscle)ReporterWaterston (unpublished) hnd-1
hlh-1 IIIAll muscle (including 8 C muscle, 4 D muscle)*Reporter, antibody, in situ hybridizationKrause et al., 1990; Seydoux and Fire, 1994 hnd-1
elt-3 IIINon-seam major epidermis (including 8 C ectoderm)Reporter Gilleard et al., 1999 elt-1
nhr-25 IIIDorsal epidermis (including 8 C ectoderm)Reporter Asahina et al., 2000 elt-1
nob-1 IIIPosterior endoderm (E) and ectoderm – mostly non-CIn situ hybridizationKohara (unpublished) cwn-1
mab-21 IVDorsal-most epidermis (including 8 C ectoderm)Reporter Ho et al., 2001 elt-3
  • Temporal phase and spatial expression pattern are summarized for 14 target genes likely to be involved in patterning. The best candidate upstream activator for each gene is the gene from the previous temporal phase with the most similar spatial expression pattern. References with supporting data measured by a variety of techniques are included where available. All reporter expression patterns are consistent with published data. *Expression is seen only in posterior muscle (C and D), where it is initiated (see Fig. 7).