Vertebrate Development Maternal to Zygotic Control (Advances in Experimental Medicine and Biology)

334 specific genes in the YSL, however, indicates that it expresses an essential ventral- izing signal in addition to its abilit ...

335 This structure, now called Hensen’s node, was subsequently discovered in all gastru- lating mammalian and avian embryos. Hen ...

336 among all vertebrates. This was confirmed when Chordin and Noggin were identi- fied as the endogenous, neural inducing, and ...

337 mesoderm (Fig. 7.8b, small arrows). Cells only become committed to these fates, however, after they invaginate through the p ...

338 culture. Comparisons of the effects of these manipulations to the normal fate maps demonstrated that cell fates depend on th ...

339 7.6.1 Transforming Growth Factor-β The first mesoderm-inducing factor, called Vegetalizing Factor, was purified from 9–13 da ...

340 gastrulation (Albano et al. 1993 , 1994 ). This suggested that either Activin was not the endogenous mesoderm-inducing facto ...

341 of a secondary primitive streak in a chick embryo when it is expressed in the lateral region of an epiblast that lacks the h ...

342 in which the type II receptor phosphorylates the type I receptor for activation. Nodal and Vg1 require an EGF-CFC co-recepto ...

343 7.6.3.1 Nodal Mutations in mouse and zebrafish demonstrate that nodal is required for mesoderm formation. The primitive stre ...

344 Derriére/Gdf-3 are all required for different aspects of mesoderm formation and patterning. In mice, the Vg1 orthologues gdf ...

345 A series of loss-of-function experiments identified Fgf4 and Fgf8 as endogenous mesoderm inducing signals in frogs and fish. ...

346 they ingress, while Fgf8 acts as a chemorepellant, driving cells away after they exit the streak. Cell movements are blocked ...

347 of the germ layers. In addition, the orthologues of Activin-B and Vg1 are expressed maternally in both frogs and fish, and c ...

348 Schulte-Merker et al. 1994 ). Conversely, endogenous Fgf signals are not able to induce mesoderm in embryos expressing a tru ...

349 expression of a nodal-transgene in the distal epiblast depends on FoxH1, a transcrip- tional effector of Nodal signaling tha ...

350 7.7.2.2 Chicken In the chicken, cNR-1 is expressed in the elongating primitive streak (Levin et al. 1995 ). COS cells expres ...

351 primitive streak begins when the hypoblast is displaced by invasion of the definitive endodermal cells from the KS (Lawson a ...

352 and ndr2/cyc in the margin depends upon the function of the EGF-CFC/Cripto/FRL co-receptor, One-Eyed Pinhead (Oep), and is e ...

353 (Fig. 7.10a). Furthermore, nodal is expressed, albeit at low levels, in the proximal epiblast of cripto−/−;cryptic−/− double ...