title: Transcription of muscle-specific actin genes in early Xenopus development: nuclear transplantation and cell dissociation.
abstract: Cloned cDNA probes that recognize muscle-specific alpha-actin gene transcripts have been used to analyze two kinds of experimental embryos in Xenopus. In one, genetically marked nuclei of larval muscle cells were transplanted to wild-type enucleated eggs; alpha-actin genes became transcriptionally inactive in the resulting blastulae but were reactivated when these embryos reached the normal stage of alpha-actin expression (late gastrula). In the other, blastula embryos reared from fertilized eggs were separated into animal, vegetal, and equatorial regions, and their cells dissociated and reaggregated. alpha-Actin RNA was synthesized at the normal time in development, but only by equatorial cells. We conclude that alpha-actin gene transcription is normally regulated in nuclear-transplant embryos and is undisturbed by the absence of cell contacts during cleavage.
mesh_terms: D000199:Actins / Q000235:genetics*; D000818:Animals; D001755:Blastocyst / Q000166:cytology; D002449:Cell Aggregation; D002450:Cell Communication; D002455:Cell Division; D002467:Cell Nucleus / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000502:physiology; D005260:Female; D005306:Fertilization; D005796:Genes; D009132:Muscles / Q000196:embryology* / Q000378:metabolism; D053652:Nuclear Transfer Techniques; D009693:Nucleic Acid Hybridization; D014158:Transcription, Genetic; D014981:Xenopus
chemical_list: D000199:Actins