Differential expression of the HMG box transcription factors XTcf-3 and XLef-1 during early xenopus development.
The recent discovery that the HMG box transcription factor XTCF-3 is involved in early axis specification in Xenopus laevis (Molenaar, M., van de Wetering, M., Oosterwegel, M., Peterson-Maduro, J. Godsave, S., Korinek, V., Roose, J., Destree, O., Clevers, H., 1996. XTcf-3 transcription factor mediates beta-catenin-induced axis formation in Xenopus embryos. Cell 86, 391-399) led us to search for other members of the TCF/LEF family in this species. A newly identified HMG box factor was cloned with highest homology to human LEF-1, called XLEF-1. Unlike XTcf-3, XLef-1 is not expressed maternally, but its transcripts become detectable directly after the mid blastula transition (MBT). At later stages, both genes are expressed in the central nervous system (CNS), eyes, otic vesicles, head mesenchyme, neural crest and derivatives, branchial arches, developing heart, tailbud and limb buds. The expression pattern of Lef-1 during later stages of development is evolutionarily conserved.
PubMed ID: 9739131
Article link: Mech Dev.
Genes referenced: lef1 tcf3 tcf7l1
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|Fig. 3. Whole mount in situ hybridisation of blastula and gastrula stage embryos with antisense XTcf-3 (A) and XLef-1 (B) probes. Of stage 7 (I + II) both the animal (I) and vegetal (II) sides are shown. Stage 12 1/2 (III) is viewed from the dorsal side.|
|Fig. 4. Whole mount in situ hybridisation of neurula, tailbud and tadpole stage embryos with antisense XTcf-3 (A) and XLef-1 (B) probes. (A) S.14 (I,II), S.18 (III), S.22 (IV), S.31 (V,VI). (B) S.14 (I) S.16 (II,III), S.22 (IV), S.31 (V,VI).|
|Fig. 5. Expression of XTcf-3 (A) and XLef-1 (B) in the developing heart (arrows). Stage 33/34 embryos cleared in BABB (33% benzylalcohol, 67% benzylbenzoate) (I) and sectioned (II).|
|Fig. 6. Dorsal view of XTcf-3 (A) and XLef-1 (B) expression in developing hind limb buds of stage 50-52 tadpoles.|
|lef1 (lymphoid enhancer-binding factor 1) gene expression in Xenopus laevis, via in situ hybridization, in NF stage 52 (far left)- NF stage 50 (far right) embryo hind limb buds.|