|
Display additional annotations [+]
Gene |
Clone |
Species |
Stages |
Anatomy |
mix1
|
|
xenopus
|
NF stage 10
|
mesoderm
,
marginal zone
,
endoderm
,
vegetal
,
endomesoderm
|
mix1
|
|
xenopus
|
NF stage 10.5
|
mesoderm
,
marginal zone
,
circumblastoporal collar
,
involuted ventral mesoderm
|
mix1
|
|
xenopus
|
NF stage 11
|
mesoderm
,
circumblastoporal collar
,
involuted ventral mesoderm
|
mix1
|
|
xenopus
|
NF stage 11.5
|
mesoderm
,
circumblastoporal collar
,
involuted ventral mesoderm
|
mix1
|
|
xenopus
|
NF stage 12
|
mesoderm
,
circumblastoporal collar
,
involuted ventral mesoderm
|
mix1
|
|
xenopus
|
NF stage 12.5
|
mesoderm
,
circumblastoporal collar
,
involuted ventral mesoderm
|
|
|
Fig. 2. Expression of Mix.1 in the marginal zone. (A) Whole mount in situ analysis of Mix.1 expression during gastrulation. Embryos are viewed from the vegetal pole. Dorsal side is up. Mix.1 is expressed in the lateral marginal zone until the mid-gastrula stage, and remains detectable in the ventral marginal zone until completion of gastrulation. (B) Comparison of Mix.1 and Xbra expression in the lateral marginal zone. Examples showing the two halves of a bisected embryo respectively hybridized with Mix.1 or Xbra probes. Bisection was made according to the dotted lines shown in panel A. At the beginning of gastrulation, Mix.1 and Xbra expression domains largely overlap. Overlapping area is smaller at the mid-gastrula stage. |
|
Display additional annotations [+]
|
|
Fig. 7. Effect of Mix.1 and Mix.2 loss of functions upon FGF4, FGF8 and Xbra expression during gastrulation. In situ hybridization analyses on mid-gastrula stage embryos (NF st. 10 further cultured 3 h at 25 °C) bisected transversally as described in Fig. 2, except for the expression of Xbra in enRMix.1-injected embryo showing a whole embryo at late gastrula stage (NF st. 10 further cultured 4 h at 25 °C). Cmo, Mo1, Mo3 or enRMix.1 were targeted to the right side of the embryos as in Fig. 4. Red Gal staining results from β-galactosidase co-expressed with morpholinos or enRMix.1. White arrowheads indicate injected sides. In response to Mo1, Mo3 and enRMix.1, FGF4 is strongly up-regulated on the injected side. Its expression is barely detected on the control side and requires longer color development times to be visible, as exemplified for the Cmo example shown. Both Mo1 and Mo3 cause an expansion of FGF8 expression in vegetal cells localized deeper in the vegetal mass or closer to the blastocoel floor. A similar expansion of Xbra expression is visible, although more limited than that of FGF4 and FGF8. Expansion of Xbra expression is more evident at late gastrula stage. |
|
Display additional annotations [+]
|
|
Fig. 9. Perturbation of FGF signals during gastrulation by Mix.1 overexpression. High dose of Mix.1 mRNA (100 pg) was injected into the two right blastomeres at the 4-cell stage, and embryos cultured until the mid-gastrula stage for in situ hybridization analysis of FGF-encoding genes (FGF3, 4, 8) or FGF-target genes (Xbra and XmyoD). Expression of all analyzed genes is inhibited indicating that Mix.1 overexpression globally interfered with FGF signals in the marginal zone. At a lower dose that does not block gastrulation (25 pg), Xbra is still down-regulated. Embryos of the same series of injection fixed at later stages express XPax-8 at the neurula stage and XSMP30 at the tailbud stage, showing that pronephros development has not been affected. |