|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
sparc
|
|
laevis
|
NF stage 18
|
notochord
,
presomitic mesoderm
,
somite
,
neural plate
,
paraxial mesoderm
,
[+]
|
sparc
|
|
laevis
|
NF stage 25
|
spinal cord
,
notochord
,
somite
,
floor plate
,
neural tube
,
[+]
|
sparc
|
|
laevis
|
NF stage 33 and 34
|
spinal cord
,
notochord
,
hypochord
,
somite
,
floor plate
,
[+]
|
sparc
|
|
laevis
|
NF stage 43
|
anterior dorsal lateral plate region
,
pharynx
|
|
|
Fig. 1. Whole-mount in situ localization of SPARCRNA during early Xenopus development. A 460 bp EcoRI fragment of the 5' region of Xenopus
SPARC was subcloned into pGEM-4Z, and digoxogenin-labeled transcripts were generated using the flanking viral promoters and cognate RNA
polymerases. (A) Shortly after neurulation (stage 18), SPARC RNA was expressed by the notochord (n), and in the segmented (s) and unsegmented (um)
somitic mesoderm (B) At stage 25, SPARC message was abundant in the notochord (n), the neural floor plate (fp), and in the somites (s). (C) By early
tailbud (stage 33). SPARC messages were no longer eVident In the notochord (n), but were abundant m the floor plate (fp) of the neural tube and subnotochordal
rod (sr) of the endoderm. (0) Towards the end of somitogenesis (stage 431 the presence of SPARC message m the dorsal axis was greatly
diminished. Expression was now up-regulated in the anterior region of the embryo where organogenesis was progressing (E) Closer examination of the
distribution of SPARC RNA within maturing somites revealed that SPARC messages at stage 25 were localized principally over the centrally located nuclei
within each myotome (sn). Very little SPARC RNA was found near the anterior and postenor poles of the myotome adjacent to the intersomitic cleft (i).
(F) As somltes matured (stage 33). SPARC RNA was no longer centrally localized above the nuclei (sn), but was now abundant at the anterior and posterior
poles of the somite, adjacent to the intersomitic cleft (i).As controls, Xenopus cyroskeletal actin cRNA (G) and SPARC sense cRNA probes (H) were used. |