hes7.1
hes5.7 hes5.2 hes5.1
Gene
TABLE 7.11
hes Genes in the Establishment of the Xenopus Midbrain/Hindbrain Boundary
See abbreviations in Table 7.3 legend.
Expression
Gain-of-Function
Loss-of-Function
Role/Details
(Dominant-Negative/Morpholino)
PN domains with a gap at the MHB.
hes5.1 overexpression : ↓MHB specif cation ( hes7.1 and pax2,
Restricts the MHB.
ISH neural plate stage) ( Takada et al., 2005 )PN domains with a gap at the MHB.
hes5.2 overexpression: ↓MHB specif cation ( pax2, ISH at
Restricts the MHB.
neural plate stage) ( Takada et al., 2005 ).
PN domains with a gap at the MHB.
hes5.7 overexpression: ↓MHB specif cation ( pax2, ISH at
Restricts the MHB.
neural plate stage) ( Takada et al., 2005 ).
Demarcates the presumptive MHB: restricted band of the
inner layer in the center of the prospective neuroectoderm
(onset: NF10.5) that is progressively resolved into a pair of
bilateral stripes ( Shinga et al., 2001 ).
Establishes the presumptive MHB region as a prepattern gene,
where it represses the putative direct target genes hes5.1,
hes5.2, hes5.7, dll1, and hes7.1.
hes7.1 overexpression : ↓MHB markers ( pax2, en2) at neural
plate stage, but ↑en2 in some cases with lower doses, while
they were unaffected at later stages ( Shinga et al., 2001 ).
↓
hes5.2, hes5.7, dll1, neurog2
hes5.1,
(neural plate stage)
( Takada et al., 2005 ).
hes7.1-VP16, mb-hes7.1 (basic region mutated), hes7.1ΔWRPW :
↓MHB markers (neural plate stage);
morphologically disrupted the MHB (tailbuds) ( Shinga et
al., 2001 ).
GR-hes7.1-VP16 (Dex NF10.5–11) +/− CHX : ↑hes5.1,
hes5.2, hes5.7, dll1, and hes7.1 domains (neural plate
stage) ( Takada et al., 2005 ).
hes7.1 MO : f lled the MHB gap with dll1, hes5.1, and hes5.7
(medial stripes of PN) and anteriorly expanded their
intermediate stripes (PN domains) ( Takada et al., 2005 ).
110
Xenopus