Chapter 6 Reconstruction of Muscle Development as a Sequence of Macromolecular Syntheses

Studies on Muscle Differentiation. Iv. Electrophoretic and Immunochemical Analyses of Tropomyosin From Adult and Embryonic Skeletal Muscles*, **

“…This fact was in good accord with the findings that the polysome population participating in tropomyosin synthcsis increased rapidly between the 14th and the 18th day of incubation (HEYWOOD and RICH, 1968) and that tropomyosin greatly increased in amount after the 14th day of incubation of the chick embryo (HERRMANN et al, 1970).…”

“…Both adult and embryonic chick tropomyosin preparations in their course of purification were observed in 8 M urea-polyacrylamide gel electrophoresis to decrease in amount of the monomeric component with a concomitant increase in number and in amount of polymerized components. It was concluded that the monomeric subunit was the major form of tropomyosin molecules in both adult and embryonic skeletal muscle extracts of the chick and that the polymerized components with inter-subunit disulfide bonds were formed in the course of purification of the preparations.Electron microscopic, immunological and biochemical studies on the formation of structural proteins and myofibrils in the differentiating muscle cells have been pursued by many workers ( r t reviews by HERRMANN et al, 1970, andby FISCHMAN, 1970). However, comparative studies on physico-chemical properties of structural proteins from adult and embryonic muscles have not yet been carried out except with myosin.…”

“…Electron microscopic, immunological and biochemical studies on the formation of structural proteins and myofibrils in the differentiating muscle cells have been pursued by many workers ( r t reviews by HERRMANN et al, 1970, andby FISCHMAN, 1970). However, comparative studies on physico-chemical properties of structural proteins from adult and embryonic muscles have not yet been carried out except with myosin.…”

Polarity of actin filaments at the initial stage of myofibril assembly in myogenic cells in vitro.

“…They are then packed into the hexagonal myofibrillar lattice with other components, e.g., troponin, tropomyosin, and a-actinin. These aggregates of filaments increase in both girth and length and soon exhibit the sarcomeric band pattern of the myofibril (3,4,8). …”

Effect of myoblast fusion during muscle cell differentiation on myosin polysome accumulation and myosin synthesis

“…It has been well established that almost all muscle tissue differentiates from mesoderm, the middle of the three primary germ layers of the embryo (Herrmann et al, 1970).…”