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Two types of antibodies directed against biochemically different antigens have been found in antisera produced by hyperimmunizing rabbits with whole homogenates of chicken or quail brain. DEAE-cellulose column chromatography was used to separate the two antibodies which, based on differences in sedimentation rate and susceptibility to inactivation by 2-mercaptoethanol, were identified as belonging to the 7S and 19S classes respectively. Although both antibodies fix complement in the presence of whole brain homogenates, the 19S fraction reacts only with the chloroform—methanol extractable portion while the 7S fraction reacts only with the residue remaining after such extraction. It is concluded that the 19S and 7S antibodies are directed against lipid or lipoprotein and protein antigens respectively. [ABSTRACT FROM AUTHOR]

Plasma membranes were prepared from primary cell cultures of normal and genetically dystrophic chick embryonic pectoral muscle. These membranes were analyzed both by one-dimensional sodium dodecyl sulphate-polyacrylamide slab gel electrophoresis and by two-dimensional electrophoresis using isoelectric focusing in the first dimension. No marked and reproducible abnormalities could be detected in the synthesis, or accumulation, of plasma membrane proteins of dystrophic muscle cells maintained in culture for periods of up to 6 days. Analysis of the relative rates of protein turnover, analysis of fucose incorporation into plasma membrane proteins, and comparison of iodinated cell surface proteins also failed to reveal distinct abnormalities in plasma membranes derived from cultured dystrophic muscle cells. Although the results obtained do not rule out an early defect in plasma membrane protein biosynthesis during the development of dystrophic skeletal muscle in vivo, they do demonstrate that the synthesis and assembly of at least the major plasma membrane proteins occur normally during the initial phases of terminal differentiation of isolated dystrophic skeletal muscle cells in tissue culture.

The thiocholine-ferricyanide method of Karnovsky and Roots for histochemical demonstration of cholinesterases has been applied to whole fetal and neonatal mice and chicks for the visualization of motor end plate patterns in superficial muscles or deeper muscles exposed by dissection.

A macromolecular fraction from mouse salivary glands markedly enhances growth of mesenchymal tissues in vitro. The same fraction causes dedifferentiation of tissues of mesodermal origin, such as muscle and cartilage. Dedifferentiated tissues do not divide but survive in good condition, while controls in the same cultural media undergo regressive changes.