WIDESPREAD EXPRESSION OF MYOD GENES IN XENOPUS EMBRYOS IS AMPLIFIED IN PRESUMPTIVE MUSCLE AS A DELAYED-RESPONSE TO MESODERM INDUCTION
- Author(s)
- Harvey, RP;
- Details
- Publication Year 1991-10,Volume 88,Issue #20,Page 9198-9202
- Journal Title
- PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
- Publication Type
- Journal Article
- Abstract
- The MyoD gene codes for an important regulatory factor in skeletal myogenesis. To explore the relationship between mesoderm induction in Xenopus embryos and expression of MyoD, I have monitored MyoD mRNA levels in normal embryos and cultured explants by RNase protection. Transcription from the two Xenopus MyoD gene copies is activated weakly across the whole embryo at the midblastula transition, and this activation occurs in the absence of mesoderm induction. In response to induction this basal expression is amplified 50- to 100-fold, but in animal-pole explants 6-10 hr elapse before induced mRNAs appear, and this induction requires prior protein synthesis. The promiscuous transcripts disappear from animal explants at a time when induction "competence" is lost, suggesting a link between these events. The data highlight a broad, but transient, permissiveness for MyoD expression in embryos, which is propagated and amplified only in presumptive muscle in response to induction. Moreover, muscle-specific MyoD expression is a relatively late (postgastrulation) event in the mesoderm-induction cascade.
- Publisher
- NATL ACAD SCIENCES
- Keywords
- DNA-BINDING; LAEVIS EMBRYOS; MYC HOMOLOGY; ENHANCER; CELLS; DIFFERENTIATION; FIBROBLASTS; MYOBLASTS; PROTEINS; SEQUENCE
- Publisher's Version
- https://doi.org/10.1073/pnas.88.20.9198
- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 1991-10-01 12:00:00