XB-ART-25605
Nature
1990 Sep 27;3476291:391-4. doi: 10.1038/347391a0.
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Graded changes in dose of a Xenopus activin A homologue elicit stepwise transitions in embryonic cell fate.
Abstract
The protein XTC-MIF, a Xenopus homologue of activin A and a potent mesoderm-inducing factor, can induce responding animal pole explants to form several different cell types in a dose-dependent manner, higher doses eliciting more dorso-anterior tissues. This graded response, characteristic of classically postulated morphogens, may underlie pattern formation, but the response of intact animal caps to XTC-MIF provides only a crude indication of trends. Here we report the effects of XTC-MIF on dispersed blastomeres rather than intact animal caps. Under these conditions, responding cells distinguish sharply between doses of pure XTC-MIF differing by less than 1.5-fold. Two different response thresholds have been found, defining three cell states. This suggests that XTC-MIF has an instructive effect. Notochord and muscle are both induced in the same narrow dose-range. Mixing treated with untreated cells does not seem to shift the dose thresholds, showing that at least some cells can stably record the received dose of inducing factor.
PubMed ID: 1699129
Article link: Nature
Species referenced: Xenopus
Genes referenced: amh inhba mif
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