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Induction of proopiomelanocortin mRNA expression in animal caps of Xenopus laevis embryos
Author(s) -
Holling Tjadine M.,
Herp François van,
Martens Gerard J. M.
Publication year - 2000
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1046/j.1440-169x.2000.00522.x
Subject(s) - xenopus , biology , noggin , proopiomelanocortin , neural development , microbiology and biotechnology , ectoderm , retinoic acid , microinjection , embryo , inducer , embryonic stem cell , medicine , endocrinology , embryogenesis , biochemistry , gene , bone morphogenetic protein , hypothalamus
To convert animal pole cells of a frog embryo from an ectodermal fate into a neural one, inductive signals are necessary. The alkalizing agent NH 4 Cl induces the expression of several anterior brain markers and the early pituitary marker XANF‐2 in Xenopus animal caps. Here it is demonstrated that NH 4 Cl also induced proopiomelanocortin (POMC)‐expressing cells (the first fully differentiated pituitary cell type) in stage 9 and 10 Xenopus animal caps, and that all‐trans retinoic acid, a posteriorizing agent, was able to block this induction when it was administered within 2 h after the start of NH 4 Cl incubation. Thus, after 2 h, the fate of Xenopus animal cap cells was determined. Microinjection of ribonucleic acid (RNA) encoding noggin, an endogenous neural inducer, led to the induction of POMC gene expression in animal caps of stage 10 embryos, suggesting that noggin represents a candidate mesodermal signal leading to the POMC messenger (m) RNA producing cell type in uncommitted ectoderm. Hence, an alkalizing agent and a neural inducer can generate a fully differentiated POMC cell lineage from Xenopus animal caps.