XB-ART-23601Dev Biol 1992 Jul 01;1521:184-7. doi: 10.1016/0012-1606(92)90168-g.
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Ectopic induction of dorsal mesoderm by overexpression of Xwnt-8 elevates the neural competence of Xenopus ectoderm.
The ectoderm of early Xenopus gastrula is competent to become induced to neural tissue, but dorsal ectoderm is more neural competent than ventral ectoderm. It is a tenable, but as yet untested possibility that the higher neural competence of dorsal gastrula ectoderm is dependent on the presence of the dorsal mesoderm. To test this hypothesis we overexpressed Xwnt-8 in order to ectopically induce dorsal mesoderm in the ventral side of the embryo. We found that this elevated the level of neural competence of ventral ectoderm to that of dorsal ectoderm. The effect of Xwnt-8 on neural competence of ventral ectoderm was strictly correlated with its ability to enhance the amount of dorsal structures. The data indicate that the presence of dorsal mesoderm is a prerequisite for establishing the differences in neural competence between gastrula dorsal and ventral ectoderm.
PubMed ID: 1385790
Article link: Dev Biol
Species referenced: Xenopus
Genes referenced: itk ncam1 prph tbx2 wnt8a
Antibodies: Epidermis Ab1
Article Images: [+] show captions
|FIG. 1. Effects of injected X’/c’ttf-X mRNA on the neural compctc~ncc~ of early gastrulu dorsal and ventral ectoderm. (A) Fertilized eggs vxrc injected with 30 pgXw,//-8 mRNA and culturcti to stage 10 earl) gastrula. Recomhinatw \vere madr between clorsxl mcsotlerm and stage 10 dorsal or ventral ectoderm, which was pwparotl hy cutting the whole animal cap into two equal pieces. For dorsal mesoderm, onI> thr inner. mesodcrmal cell layers from the blastoporc region of a stage 10 early gastrula wrc used. Rccombinates \vcrc cultured to stage 24 twforc RNA was isolatctl. The cxprcssion of neural-spccilic gicnes in 10 pg RNA n-as monitored by RN;w protection. using the protws for the neural-spccilic genes XII”3 and N-CA1CI. The tts\el of 5S transcripts leas monitor4 to dtmonstratc cquat amounts of RNA. (BI 5 pg X/r,t//-8 mRNrl !vas injccteti into either a ticar. 1 ventral animal hlastomere or ;I tier 1 ventral vvgtital hlastonicrc of‘ a 32-cvll cmhryo. Thv emt)ryos n-rrcs cultured to stag,’ 10 gastrnla anti rccomt)in;ttt~s wow made and cultured as in A.|
|2. The expression of the epidermal marker Epi 1 aftcar owrexprcwion of X/at/f-8. Fertilized eggs were injected with 50 pg Xwi/t-S mRNA and cultured to stage 10 early gastrula. Dorsal and ventral wtoderm explants, prepared by cutting the whole animal cap into two cclual pieces, were cultured to stage 11. The explants were then prowssed for immunocgtochcmistr~ using the monoclonal antibody Epi 1 which specilicallg stains epidermal tissue (London et trl.. 19881. Staining was visualised using indirect immunofluorescence.|