title: Analysis of myogenesis with recombinant DNA techniques.
abstract: Recombinant phages containing the rat skeletal muscle alpha-actin gene and the cytoplasmic beta-actin gene were isolated and the structure of these genes was determined. Both genes contain a large intron in the 5' untranslated region and smaller introns at codons 41, 267 and 327. In addition, the alpha-actin contains introns at codons 150 and 204 not present in the beta-actin gene, whereas the beta-actin gene contains an intron at codon 121. The evolutionary aspects of these findings are discussed. Active genes are organized in chromatin in a conformation which renders them preferentially sensitive to digestion with nucleolytic enzymes. The DNAase I sensitivity of genes programmed to be expressed during myogenesis was tested in a cloned cell population of a myogenic cell line. It was found that these genes are not preferentially sensitive to DNAase I in the chromatin of proliferating mononucleated cells. They become DNAase I sensitive during terminal differentiation.
mesh_terms: D000199:Actins / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D004274:DNA, Recombinant / Q000378:metabolism*; D003850:Deoxyribonuclease I; D004706:Endodeoxyribonucleases; D005796:Genes; D009132:Muscles / Q000378:metabolism / Q000502:physiology*; D051381:Rats
chemical_list: D000199:Actins; D004274:DNA, Recombinant; D004706:Endodeoxyribonucleases; D003850:Deoxyribonuclease I