|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
eya1
|
|
laevis
|
NF stage 13
to
NF stage 14
|
pre-chordal neural plate
,
trigeminal placode
,
lens placode
,
neural plate
,
lateral
,
[+]
|
six1
|
|
laevis
|
NF stage 13
to
NF stage 14
|
pre-chordal neural plate
,
neural crest
,
trigeminal placode
,
lens placode
,
neural plate
,
[+]
|
six4
|
|
laevis
|
NF stage 13
to
NF stage 14
|
pre-chordal neural plate
,
trigeminal placode
,
lens placode
,
neural plate
,
lateral
|
pax3
|
|
laevis
|
NF stage 13
to
NF stage 14
|
anterior neural fold
,
cranial neural crest
,
profundal placode
,
neural plate border
|
pax8
|
|
laevis
|
NF stage 13
to
NF stage 14
|
intermediate mesoderm
|
pax6
|
|
laevis
|
NF stage 13
to
NF stage 14
|
pre-chordal neural plate
,
chordal neural plate
,
trigeminal placode
,
neural plate
|
sox2
|
|
laevis
|
NF stage 13
to
NF stage 14
|
pre-chordal neural plate
,
trigeminal placode
,
neural plate
,
lateral
|
sox3
|
|
laevis
|
NF stage 13
to
NF stage 14
|
pre-chordal neural plate
,
chordal neural plate
,
trigeminal placode
,
neural plate
,
profundal placode
,
[+]
|
pax2
|
|
laevis
|
NF stage 13
to
NF stage 14
|
pre-chordal neural plate
|
msx1
|
|
laevis
|
NF stage 13
to
NF stage 14
|
neural crest
,
trigeminal placode
,
lens placode
,
neural plate
,
profundal placode
,
[+]
|
tbx2
|
|
laevis
|
NF stage 13
to
NF stage 14
|
cement gland primordium
|
dlx3
|
|
laevis
|
NF stage 13
to
NF stage 14
|
ectoderm
,
cement gland primordium
,
trigeminal placode
,
lens placode
,
neural plate border
,
[+]
|
foxi4
|
|
laevis
|
NF stage 13
to
NF stage 14
|
trigeminal placode
,
neural plate
,
lateral
,
anterior neural fold
,
profundal placode
,
[+]
|
|
|
Fig. 1. Placodal gene expression patterns in neural plate stage Xenopus embryos (stages 13–14) in dorsal view (anterior is to the left, all embryos are equally oriented). To facilitate comparison of the placodal expression domains of different genes, color-coded arrows and arrowheads corresponding to different placodal expression domains of Pax genes are used for the identification of comparable regions of gene expression (for more detailed labeling, see Fig. 12). Colors are explained in the schematic drawing, which depicts the approximate relative position of some gene expression domains and lists the placodes to which they will give rise subsequently. Green arrowheads identify placodal gene expression immediately rostral to the anterior neural plate border (prospective adenohypophysial placode medially and prospective olfactory placodes laterally), whereas green arrows identify placodal gene expression rostrolateral to the anterior neural plate (prospective lens and trigeminal placodes). Black arrows in D indicate the border of Dlx3 expression in superficial ectoderm, which extends further medial than its border of expression in the deep ectodermal layer (colored arrows). Black arrowheads in E indicate Msx1 expression in anterior neural plate. White asterisks in E and L indicate expression of Msx1 and Pax3, respectively, in a region encompassing neural crest and lateralmost neural plate. For detailed description, see text. Abbreviations: Ad/Ol, anterior placodal area, from which adenohypophysial (Ad) and olfactory (Ol) placodes develop; anp, anterior neural plate; cg, cement gland; L, lens placode; LL/Ot/EB, posterior placodal area, from which lateral line (LL), otic (Ot), and epibranchial (EB) placodes develop; np, neural plate; PN, pronephros; Pr, profundal placode; pnp, posterior neural plate; V, trigeminal placode. |
|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
eya1
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
otic vesicle
,
trigeminal placode
,
epibranchial placode
,
lateral line placode
,
profundal placode
,
[+]
|
six1
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
olfactory placode
,
otic placode
,
epibranchial placode
,
profundus ganglion
,
trigeminal ganglion
,
[+]
|
six4
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
otic vesicle
,
epibranchial placode
,
profundus ganglion
,
trigeminal ganglion
,
lateral line placode
|
pax3
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
hindbrain
,
hatching gland
,
pronephric sinus
,
trigeminal ganglion
|
pax8
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
otic vesicle
,
pronephric duct
,
epibranchial placode
,
pronephric kidney
|
pax6
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
olfactory placode
,
lens
,
diencephalon
,
midbrain
,
spinal cord
,
[+]
|
sox2
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
olfactory placode
,
otic vesicle
,
lens
,
forebrain
,
midbrain
,
[+]
|
sox3
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
olfactory placode
,
otic vesicle
,
lens
,
forebrain
,
midbrain
,
[+]
|
pax2
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
otic vesicle
,
hindbrain
,
midbrain-hindbrain boundary
,
spinal cord
,
pronephric duct
,
[+]
|
msx1
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
otic vesicle
,
lens
,
branchial arch
,
lens placode
,
ventral
,
[+]
|
msx1
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
otic vesicle
,
hindbrain
,
branchial arch
,
ventral
|
tbx2
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
otic vesicle
,
lens
,
branchial arch
,
trigeminal placode
,
optic vesicle
,
[+]
|
dlx3
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
olfactory placode
,
otic vesicle
,
pharyngeal arch
,
epibranchial placode
|
foxi4
|
|
laevis
|
NF stage 32
to
NF stage 33 and 34
|
pharyngeal arch
,
trigeminal placode
,
epibranchial placode
,
profundus ganglion
,
trigeminal ganglion
,
[+]
|
|
|
Fig. 11. Placodal gene expression patterns in late tail bud Xenopus embryos (stages 32–34) in lateral views (anterior is to the left). As in Fig. 9, color-coded arrows and arrowheads are used for the identification of comparable regions of gene expression. Expression in the lens is indicated by L. Colors are explained in the schematic drawing, depicting the distribution of placodes in a stage 33/34 embryo (modified after Schlosser and Northcutt, 2000; see Fig. 14 for detailed explanation). By stage 33/34, the profundal placode has disappeared, the trigeminal placode is shrinking rapidly, the lens placode and otic placode have completely invaginated to form the lens and the otic vesicle, respectively, and the lateral line primordia have begun to extend from the lateral line placodes (Schlosser and Northcutt, 2000). Again, orange and brown double arrows indicate expression of the respective genes in a region encompassing facial epibranchial placode and anteroventral lateral line placode. White asterisks indicate gene expression in the pharyngeal pouches. Green and yellow asterisks indicate gene expression in the trigeminal and profundal ganglia (which are fused proximately), respectively. For detailed description, see text. Abbreviations: bam, branchial arch mesenchyme; L, lens; Ot, otic vesicle; vba, ventral branchial arch region (all three germ layers). For additional abbreviations, see Fig. 1. |