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Fig. 8. Model of transcriptional regulation of VM-metameric genes during stages
10-11. Ventrolateral view of VM is shown schematically. Gray strip, ectodermal
cell layer. Green and brown-outlined boxes, ectodermal WG and HH sources,
respectively. Blue horizontal arrows in the top diagram show the posterior
expansion of the VM competent region; black arrows indicate activation;
black-T-shaped-lines indicate repression. WG and HH susceptible regions are
shown by colored lines along the future VM. tin/bnl/bap (green),
VM-hh (yellow) and con (crimson) expression are indicated.
Reduced con expression at the anterior end of VM-PSs is indicated in
pink. For simplicity, three gene groups are separately depicted in three
successive VM-PSs. See the text for details.