title: Isoform-specific cDNAs for human embryonic, neonatal, and slow skeletal myosin heavy chains.
abstract: A series of cDNA fragments encoding immunodetectable portions of the human slow/beta, neonatal, and embryonic isoforms of myosin heavy chain (MHC) were isolated from a human fetal muscle cDNA expression library. A 6 kb fragment isolated on a secondary screen represents the first cloned cDNA encoding a full-length vertebrate MHC (the human embryonic isoform). In the 3'-untranslated regions, 70-80% nucleotide sequence homology exists among orthologous human and rat cDNAs, whereas the homology is less than 65% among the paralogous cDNAs. Furthermore, approximately the same level of untranslated sequence conservation is observed at the 5'-terminus of the embryonic transcript. These results suggest that for both the 3'- and the 5'-untranslated domains, the rate of evolutionary sequence divergence is limited by functional constraints.
authors: Department of Anatomy, School of Medicine, University of Pennsylvania, Philadelphia 19104.
authors: H H
authors: HH
authors: Stedman
authors: A M
authors: AM
authors: Kelly
authors: N A
authors: NA
authors: Rubinstein
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D004622:Embryo, Mammalian; D015723:Gene Library; D006801:Humans; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D009132:Muscles / Q000196:embryology / Q000502:physiology; D015879:Myosin Subfragments / Q000235:genetics*; D009218:Myosins / Q000235:genetics*; D051381:Rats; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
chemical_list: D015879:Myosin Subfragments; D004247:DNA; D009218:Myosins