|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
runx2
|
|
laevis
|
NF stage 31
to
NF stage 33 and 34
|
mandibular crest
,
cartilage tissue
,
cranial neural crest
,
head
|
runx2
|
|
laevis
|
NF stage 35 and 36
|
mandibular arch
,
cartilage tissue
,
head
,
chondrocranium
|
runx2
|
|
laevis
|
NF stage 39
|
neural crest
,
mandibular arch
,
cartilage tissue
,
head
|
runx2
|
|
laevis
|
NF stage 41
|
mandibular arch
,
cartilage tissue
,
head
,
Meckel's cartilage
|
|
|
Figure 2. In situ hybridizations of runx2 and sox9 in the mandibular neural crest stream. A: Anterior views of the head showing the distribution of both transcripts over several developmental stages. Runx2 mRNA expression is first apparent in the pre-chondrogenic suprarostral plate (SP) by stage 31. Additional expression appears in the cranial trabeculae (CT) by stage 35/36 (see Fig. 3). This expression is in a subset of the mandibular arch crest (MA), which expresses sox9. The expression of sox9 mRNA is progressively restricted to co-localize with runx2. By stage 39, both transcripts overlap in the presumptive suprarostal plate (SP). The expression of runx2 decreases in the suprarostral plate by stage 41, although some expression persists in the palatoquadrate anlagen (PQ). Sox9 expression in the suprarostral plate is fused in the midline by stage 41, with continued expression in the palatoquadrate and new expression in the infrarostral (IR) and Meckel's cartilages (MC). B: Ventral views of stage 39 embryos stained with runx2 and sox9. The cement gland has been removed with a scalpel. Both transcripts are expressed in the future ceratohyal (CH) and palatoquadrate cartilages. The latter is clearly divided into a posterior sub-ocular arc (SA) and anterior quadratocranial commissure (QC), which connects to the suprarostral plate dorsally. There is a small flange of staining off of the palatoquadrate in both preparations that reveals the future Meckel's cartilage (asterisk). |
|
Gene |
Clone |
Species |
Stages |
Anatomy |
sox9.S
|
|
laevis
|
NF stage 33 and 34
|
neural crest
,
mandibular arch
,
hyoid arch
,
branchial arch
,
head
,
[+]
|
sox9.S
|
|
laevis
|
NF stage 35 and 36
|
mandibular arch
,
hyoid arch
,
branchial arch
,
cartilage tissue
,
head
,
[+]
|
sox9.S
|
|
laevis
|
NF stage 39
|
mandibular arch
,
hyoid arch
,
branchial arch
,
cartilage tissue
,
head
,
[+]
|
sox9.S
|
|
laevis
|
NF stage 41
|
mandibular arch
,
hyoid arch
,
branchial arch
,
cartilage tissue
,
head
,
[+]
|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
runx2
|
|
laevis
|
NF stage 35 and 36
|
hyoid crest
,
hyoid arch
,
cartilage tissue
,
head
|
runx2
|
|
laevis
|
NF stage 39
|
hyoid arch
,
cartilage tissue
,
head
|
runx2
|
|
laevis
|
NF stage 41
|
cartilage tissue
,
head
,
braincase and otic capsule skeleton
|
runx2
|
|
laevis
|
NF stage 33 and 34
|
cartilage tissue
,
head
|
cbfb
|
|
laevis
|
NF stage 33 and 34
to
NF stage 35 and 36
|
neural crest
,
branchial arch
,
cartilage tissue
,
head
|
cbfb
|
|
laevis
|
NF stage 39
to
NF stage 41
|
cartilage tissue
,
head
,
chondrocranium
|
col2a1
|
|
laevis
|
NF stage 33 and 34
to
NF stage 35 and 36
|
notochord
,
branchial arch
,
head
,
braincase and otic capsule skeleton
|
col2a1
|
|
laevis
|
NF stage 39
to
NF stage 41
|
notochord
,
branchial arch
,
cartilage tissue
,
head
,
chondrocranium
,
[+]
|
|
|
Figure 3. In situ hybridizations of runx2, sox9, collagen2a1, and cbfb. All images are lateral views, anterior to the right. Runx2 expression begins in the presumptive suprarostral plate (SP). It expands to the anlage of the cranial trabeculae (CT) and a faint portion of the hyoid arch crest (HA) by stage 35/36. Runx2 staining includes the future ceratobranchial (CB) and ceratohyal (CH) cartilages by stage 39, and is additionally found in the otic capsule (OC) by stage 41. The expression of runx2 in the ceratohyal decreases during stage 41 as this element begins to chondrify. The distribution of sox9 is more extensive than that of runx2 by stage 33/34, with strong expression in the mandibular (MA), hyoid (HA), and branchial (BA) arch neural crest streams. Its expression in the crest becomes restricted by stage 35/36 with a clear distribution in the precursors of the future palatoquadrate and continued expression in the hyoid and branchial arches. By stage 39, both runx2 and sox9 are co-expressed in the future cartilaginous elements. Sox9 expression in the ceratohyal is also diminished by stage 41 with the onset of chondrogenesis. Col2a1 is distributed through the notochord and otic capsule along with a subset of the branchial arches (BA) and presumptive suprarostral plate by stage 33/34. Col2a1 is expressed widely throughout the head during the stages examined with intensifying staining in the presumptive cranial cartilages by stages 39 and 41. The runx co-factor cbfb is expressed throughout the head during development, with stronger expression in the presumptive ceratohyal and palatoquadrate by stage 39. |