|
Gene |
Clone |
Species |
Stages |
Anatomy |
sema5b.S
|
|
laevis
|
NF stage 11
to
NF stage 12
|
axial mesoderm
|
sema5b.S
|
|
laevis
|
NF stage 14
to
NF stage 15
|
notochord
,
posterior
,
preplacodal ectoderm
|
sema5b.S
|
|
laevis
|
NF stage 16
to
NF stage 19
|
notochord
,
prechordal plate
,
neural plate
,
posterior
,
preplacodal ectoderm
|
sema5b.S
|
|
laevis
|
NF stage 23
to
NF stage 27
|
notochord
,
tail region
,
eye
,
paraxial mesoderm
,
anterior dorsal lateral plate region
|
sema5b.S
|
|
laevis
|
NF stage 28
to
NF stage 32
|
notochord
,
tail region
,
optic vesicle
,
paraxial mesoderm
,
pronephric kidney
,
[+]
|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
sema6d
|
|
laevis
|
NF stage 11
to
NF stage 12
|
axial mesoderm
|
sema6d
|
|
laevis
|
NF stage 14
to
NF stage 15
|
axial mesoderm
|
sema6d
|
|
laevis
|
NF stage 16
to
NF stage 19
|
prechordal plate
,
anterior neural ridge
|
sema6d
|
|
laevis
|
NF stage 23
to
NF stage 27
|
hatching gland
,
periocular region
|
sema6d
|
|
laevis
|
NF stage 28
to
NF stage 32
|
hatching gland
,
notochord
,
somite
,
branchial arch
,
periocular region
|
sema6a
|
|
laevis
|
NF stage 14
to
NF stage 15
|
neural crest
,
involuted dorsal mesoderm
,
cranial neural crest
|
sema6a
|
|
laevis
|
NF stage 16
to
NF stage 19
|
neural crest
,
cranial neural crest
,
preplacodal ectoderm
|
sema6a
|
|
laevis
|
NF stage 23
to
NF stage 27
|
otic vesicle
,
tail region
,
optic vesicle
,
intersomitic region
|
sema6a
|
|
laevis
|
NF stage 28
to
NF stage 32
|
otic vesicle
,
tail region
,
branchial arch
,
eye
,
intersomitic region
|
sema6b
|
|
laevis
|
NF stage 16
to
NF stage 19
|
hypophyseal primordium
,
neural fold
|
sema6b
|
|
laevis
|
NF stage 23
to
NF stage 27
|
presomitic mesoderm
,
somite
|
sema6b
|
|
laevis
|
NF stage 28
to
NF stage 32
|
otic vesicle
,
presomitic mesoderm
,
somite
|
|
|
Figure 4. Expression of Sema5B and the class-6 semaphorins in Xenopus laevis. ba, branchial arches; e, eye; no, notochord; op, otic placode; p, pronephros; pnc, premigratory neural crest cells; s, somites. |
|
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|
|
Figure 5. Semaphorin expression in the mesoderm and notochord during neurula stages. A-G: Neurula stage embryos were stained by in situ hybridization and transversally sectioned. Left: Whole embryo, dashed line indicates the plane of the transverse section. Right: Enlargement of the neural tube area of the transverse section. A: Sema3A is expressed in the somitogenic mesoderm. B: Sema4B expression delineates the boundaries of the somitogenic mesoderm. C: Sema6B is expressed in the somitogenic mesoderm. D: Sema3F is expressed in the notochord as well as the spinal cord anlage and the archenteron roof. E-G: Sema4C, Sema4D, and Sema5B are expressed in the notochord. arc, archenteron roof cells; m, somitogenic mesoderm; no, notochord; sca, spinal cord anlage. |
|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
twist1
|
|
laevis
|
NF stage 28
|
mandibular crest
,
hyoid crest
,
neural crest
,
cranial neural crest
,
anterior branchial crest
,
[+]
|
sema3d
|
|
laevis
|
NF stage 29 and 30
|
otic vesicle
,
midbrain-hindbrain boundary
,
neural crest
,
posterior neural tube
,
cranial placode
,
[+]
|
egr2
|
|
laevis
|
NF stage 28
|
cranial neural crest
,
rhombomere
,
rhombomere R3
,
rhombomere R5
,
posterior branchial crest
|
sema4c
|
|
laevis
|
NF stage 28
|
cement gland
,
neural crest
,
otic placode
,
cranial neural crest
,
anterior branchial crest
,
[+]
|
sema4g
|
|
laevis
|
NF stage 32
|
eye
,
otic placode
|
sema4b
|
|
laevis
|
NF stage 25
|
cement gland
,
neural crest
,
otic placode
,
pronephric mesenchyme
|
sema3fl
|
|
laevis
|
NF stage 28
|
midbrain-hindbrain boundary
,
cranial placode
,
cranial neural crest
,
rhombomere
,
rhombomere R3
,
[+]
|
sema3a
|
|
laevis
|
NF stage 25
|
diencephalon
,
midbrain-hindbrain boundary
,
mandibular crest
,
neural crest
,
somite
,
[+]
|
sema3a
|
|
laevis
|
NF stage 29 and 30
|
diencephalon
,
anterior dorsal lateral plate region
|
sema3a
|
|
laevis
|
NF stage 32
|
diencephalon
,
midbrain-hindbrain boundary
,
mandibular crest
,
somite
,
lateral plate mesoderm
,
[+]
|
sema6d
|
|
laevis
|
NF stage 29 and 30
|
otic placode
,
cranial neural crest
,
neural tube
|
sema6a
|
|
laevis
|
NF stage 28
|
otic vesicle
,
midbrain-hindbrain boundary
,
optic vesicle
,
lateral plate mesoderm
,
anterior dorsal lateral plate region
|
sema3c
|
|
laevis
|
NF stage 28
|
forebrain
,
neural crest
,
otic placode
,
cranial placode
,
cranial neural crest
|
sema4a
|
|
laevis
|
NF stage 29 and 30
|
neural crest
,
cranial placode
,
periocular region
|
sema6b
|
|
laevis
|
NF stage 32
|
otic vesicle
,
spinal cord
,
neural crest
,
cardiac neural crest
|
|
|
Figure 7. Semaphorins are expressed in close proximity to migrating cranial neural crest cells. In situ hybridization of tadpole-stage embryos; enlargements of the head are shown. Red arrows indicate migrating neural crest cells, white arrows indicate neurogenic placodes. A: Sema3A expression. Staining in the midbrain hindbrain boundary was confirmed by double in situ hybridization with engrailed (data not shown). B: Sema3C expression. C: Sema3D expression. D: Sema3F expression. Double in situ hybridization using Krox20 or engrailed antisense probes was used to confirm staining in the rhombomeres or the midbrain hindbrain boundary, respectively (data not shown and Q). E: Sema4A expression. F: Sema4B expression. G: Sema4C expression. H: Sema4G expression. I: Sema5B expression. K: Sema6A expression. L: Sema6B expression. M: Sema6D expression. N: Sema3A expression at early tadpole stage. O: Double in situ hybridization using a Sema3A (blue) and a twist (red) antisense probe at tadpole stage. Sema3A expression is localized posterior to the migrating twist-expressing neural crest cells (black arrow). P: For comparison twist expression at tadpole stage is shown. Q: Double in situ hybridization showing Sema3F (blue) expression adjacent to the anterior portion of the migrating Krox20-expressing (red) neural crest cells (black arrow). cg, cement gland; e, eye; mh, midbrain hindbrain boundary; op, otic placode; r3, rhombomere 3; r5, rhombomere 5. |
|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
sema4d
|
|
laevis
|
NF stage 31
|
notochord
|
sema4d
|
|
laevis
|
NF stage 31
|
notochord
|
sema4c
|
|
laevis
|
NF stage 31
|
spinal cord
,
roof plate
,
head region
,
heart
,
branchial arch
,
[+]
|
sema4b
|
|
laevis
|
NF stage 26
|
cement gland
,
otic placode
,
proctodeum
,
pronephric kidney
,
intersomitic region
|
sema3fl
|
|
laevis
|
NF stage 25
|
spinal cord
,
notochord
,
hypochord
,
branchial arch
,
floor plate
,
[+]
|
sema3fl
|
|
laevis
|
NF stage 25
|
spinal cord
,
notochord
,
hypochord
,
branchial arch
,
floor plate
,
[+]
|
sema3a
|
|
laevis
|
NF stage 26
|
head region
,
presomitic mesoderm
,
somite
,
splanchnic layer of lateral plate mesoderm
|
sema6b
|
|
laevis
|
NF stage 22
|
somite
,
otic placode
|
sema6b
|
|
laevis
|
NF stage 22
|
somite
,
otic placode
|
sema6b
|
|
laevis
|
NF stage 35 and 36
|
forebrain
,
hindbrain
,
spinal cord
,
eye
,
hypaxial muscle
,
[+]
|
|
|
Figure 6. Semaphorin expression in the mesoderm and notochord at tadpole stages. In situ hybridization of the whole embryo (left), dashed line indicates the plane of the transverse section (right). A: Sema3A is expressed in the somites and the splanchnic mesoderm. B: Sema4B expression in the mesoderm is replaced by pronephros, cement gland, otic placode, proctodeum, spinal cord, and gut expression. C: Sema6B is expressed in the somites and otic placode at late neurula stages. D: At tadpole stages, the somite expression is limited to the dorsal and lateral margins of the somites (white arrow). E: Sema3F expression is detected in the notochord, but also in the spinal cord, the hypochord, the posterior endoderm, and the branchial arches. F: Sema4C notochord expression is replaced by expression in the posterior cardinal vein, the heart, and the branchial arches. G: Sema4D expression is detected in the notochord. H: Sema5B expression in the notochord is replaced by spinal cord, pronephros, brain, and eye expression. ba, branchial arches; cg, cement gland; en, endoderm; g, gut; h, heart; hc, hypochord; no, notochord; op, otic placode; p, pronephros; pcv, posterior cardinal vein; pd, proctodeum; s, somites; sc, spinal cord; sm, splanchnic mesoderm. |