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R C Strohman

Publications and source records attributed to R C Strohman.

54 records · Page 3Linked to original sources
PubMed1978

Diazepam inhibits myoblast fusion and expression of muscle specific protein synthesis.

The presence of diazepam in culutres of chicken embryo myoblasts arrests normal muscle cell differentiation. High concentrations of the drug reversibly prevent myoblasts from fusing to form multinucleated myotubes. Lower concentrations of diazepam allow cell fusion to occur, but inhibit the synthesis and accumulation of myosin heavy chain, implying that cell fusion does not obligate myoblasts to synthesize and accumulate large quantities of muscle specific protein. The effect of diazepam on muscle cells in culture is direct and specific.

Animals↗
PubMed1977

Messenger RNA for myosin polypeptides: isolation from single myogenic cell cultures.

Messenger RNA which stimilates the synthesis of myosin heavy chain in a reticulocyte lysate has been isolated from single myogenic cell cultures. Specific myosin polypeptides have been identified by immunoprecipitation with an antibody made to purified adult chicken skeletal muscle myosin. This mRNA binds to oligo(dT)-cellulose, and an active fraction from sucrose gradients migrates as 26S on formamide-polyacrylamide gels. The relative amount of this RNA increases dramatically at the time of terminal differentiation.

Cell Differentiation↗
PubMed1974

Myosin heavy chain messenger RNA from myogenic cell cultures.

The appearance of messenger RNA for myosin heavy chains in chick-embryo myogenic cell cultures was investigated. Total polyribosomes were isolated from cultures at various times of development and were purified in sucrose step gradients. These polysomes were either extracted with phenol or were treated with puromycin. The ribonucleoprotein particles and ribosomal subunits released by puromycin were fractionated on sucrose gradients. RNA from polysomes or from puromycin-dissociated subunits was fractionated on oligo(dT)-cellulose columns, and the bound and unbound RNA was assayed for activity of myosin heavy chain messenger RNA in a rabbit reticulocyte cell-free system. RNA stimulating myosin heavy-chain synthesis was found predominantly in the unbound fractions of the oligo(dT)-cellulose columns. After puromycin treatment of polysomes, the myosin heavy chain messenger RNA, which sediments at 18-26 S, was associated with a ribonucleoprotein particle sedimenting between 30 and 40 S. Myosin heavy chain messenger RNA was obtained from cultures containing well-developed myotubes and from cultures undergoing myogenic cell fusion. This messenger RNA was not detectable in early, unfused cultures, or in later cultures in which myogenic cell fusion had been prevented by treatment with ethyleneglycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid. These experiments demonstrate that messenger RNA for myosin heavy chains becomes associated with ribosomes only after myogenic cell fusion has begun.

Acetates↗
PubMedDate not supplied

Linear genetics, non-linear epigenetics: complementary approaches to understanding complex diseases.

Recent discoveries and rediscoveries in molecular and cell biology, in population and evolutionary biology, and in disease natural history raise new doubts about the ability of genetic analysis alone to predict multifactorial (polygenic) human diseases and other complex phenotypes. These doubts serve to redirect our attention to epigenetic regulation as a second informational system in parallel with the genome. Epigenetic regulation is now viewed by many biologists as a process that includes mechanisms capable of constraining the genome and providing for new patterns of gene expression. Epigenetic networks, both intra- and inter-cellular, provide a basis for nonlinear and chaotic views of cellular and tissue level differentiation and organization, and thus provide a more dynamic approach to understanding the creation of complex phenotypes, even from isogeneic conditions. The reality of regulatory networks within cells inserted, as it were, between genome and phenome, also helps explain the difficulties now encountered when prediction and diagnosis of complex disease omits epigenetic considerations and depends entirely on gene causality.

Animals↗