TY - JOUR
T1 - Mesoderm induction in Xenopus is a zygotic event regulated by maternal VegT via TGFβ growth factors
AU - Kofron, Matt
AU - Demel, Teresa
AU - Xanthos, Jenny
AU - Lohr, Jamie
AU - Sun, Benjamin
AU - Sive, Hazel
AU - Osada, Shin Ichi
AU - Wright, Chris
AU - Wylie, Chris
AU - Heasman, Janet
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1999/12
Y1 - 1999/12
N2 - The maternal transcription factor VegT is important for establishing the primary germ layers in Xenopus. In previous work, we showed that the vegetal masses of embryos lacking maternal VegT do not produce mesoderm-inducing signals and that mesoderm formation in these embryos occurred ectopically, from the vegetal area rather than the equatorial zone of the blastula. Here we have increased the efficiency of the depletion of maternal VegT mRNA and have studied the effects on mesoderm formation. We find that maternal VegT is required for the formation of 90% of mesodermal tissue, as measured by the expression of mesodermal markers MyoD, cardiac actin, Xbra, Xwnt8 and alphaT4 globin. Furthermore, the transcription of FGFs and TGFβs, Xnr1, Xnr2, Xnr4 and derriere does not occur in VegT-depleted embryos. We test whether these growth factors may be endogenous factors in mesoderm induction, by studying their ability to rescue the phenotype of VegT-depleted embryos, when their expression is restricted to the vegetal mass. We find that Xnr1, Xnr2, Xnr4 and derriere mRNA all rescue mesoderm formation, as well as the formation of blastopores and the wild-type body axis. Derriere rescues trunk and tail while nr1, nr2 and nr4 rescue head, trunk and tail. We conclude that mesoderm induction in Xenopus depends on a maternal transcription factor regulating these zygotic growth factors.
AB - The maternal transcription factor VegT is important for establishing the primary germ layers in Xenopus. In previous work, we showed that the vegetal masses of embryos lacking maternal VegT do not produce mesoderm-inducing signals and that mesoderm formation in these embryos occurred ectopically, from the vegetal area rather than the equatorial zone of the blastula. Here we have increased the efficiency of the depletion of maternal VegT mRNA and have studied the effects on mesoderm formation. We find that maternal VegT is required for the formation of 90% of mesodermal tissue, as measured by the expression of mesodermal markers MyoD, cardiac actin, Xbra, Xwnt8 and alphaT4 globin. Furthermore, the transcription of FGFs and TGFβs, Xnr1, Xnr2, Xnr4 and derriere does not occur in VegT-depleted embryos. We test whether these growth factors may be endogenous factors in mesoderm induction, by studying their ability to rescue the phenotype of VegT-depleted embryos, when their expression is restricted to the vegetal mass. We find that Xnr1, Xnr2, Xnr4 and derriere mRNA all rescue mesoderm formation, as well as the formation of blastopores and the wild-type body axis. Derriere rescues trunk and tail while nr1, nr2 and nr4 rescue head, trunk and tail. We conclude that mesoderm induction in Xenopus depends on a maternal transcription factor regulating these zygotic growth factors.
KW - Growth factor
KW - Induction
KW - Mesoderm
KW - VegT
KW - Xenopus
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M3 - Article
C2 - 10572051
AN - SCOPUS:18744431466
SN - 0950-1991
VL - 126
SP - 5759
EP - 5770
JO - Development
JF - Development
IS - 24
ER -