XB-IMG-134316
Xenbase Image ID: 134316
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FIG. 8. FGF signaling is specifically required in the neurectoderm
for complete anterior–posterior neural patterning. Explants of dorsal
ectoderm (DE) were prepared from stage 10-minus gastrulae that
had been previously injected with d50 or XFD RNA (4 dorsal
animal injection sites, total of 4 ng RNA per embryo). Posterior
mesoderm was obtained from stage 12 embryos. d50-injected
embryos express neural markers and muscle actin (lane 1). For
RT–PCR, cDNA was prepared from explants and embryos at stage
27. Embryos injected with XFD RNA express all neural markers,
but have a decrease in muscle actin (lane 2; note that XFD injection
was limited to the animal pole and dorsal midline). Uninduced
explants of dorsal ectoderm (XFD and d50) do not express significant
amounts of neural tissue (lanes 3 and 5). Posterior mesoderm
can induce dorsal ectoderm expressing d50 RNA to form neural
tissue of all anterior–posterior levels (lane 4). Blocking of FGF
signaling specifically in dorsal ectoderm (with XFD RNA) inhibits
the induction of spinal cord and hindbrain by posterior mesoderm
and enhances anterior development (lane 6). Posterior mesoderm,
cultured alone, forms muscle but not neural tissue (lane 7). Image published in: Holowacz T and Sokol S (1999) Copyright © 1999. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View |