The formation of muscle and muscle‐like elements in the chorioallantoic membrane following inoculation of a mixture of cardiac microsomes and Rous sarcoma virus

Abstract

NINE FIGURESAbout 20 years ago the fields of cell physiology and cytology were benefited immeasurably by a transfusion of ideas and techniques from the field of virology, when attention was focused on the method of differential centrifugation for the isolation of normal cellular components and viruses (Claude, '37, '38; cf. Ebert, '59). I n the intervening years animal virology and cell physiology have gone their separate ways and only now are reconverging. Ebert and Wilt ('60) have asked whether we are ready to apply the ideas and methods of animal virology to studies of development.

An Electron Microscopic Study of the Chorioallantoic Membrane Following Infection With Rous Sarcoma Virus

“…Investigations by many workers have implicated the ectoderm in the initial phase of RSV infection of the CAM (3,6,12,20,26,29,30). Our electron microscopic studies do not confirm these findings; in fact, they indicate that the cells of the mesoderm may be primarily involved in the production of the lesions within this organ.…”

“…Investigations by many workers have implicated the ectoderm in the initial phase of RSV infection of the CAM (3,6,12,20,26,29,30). Our electron microscopic studies do not confirm these findings; in fact, they indicate that the cells of the mesoderm FIGURE 12 Low-power electron micrograph of CAM ectoderm, 6 days postinfection, showing degenerate sinusoidal cells (Sc), electron-opaque ectoderm proper, and lightly stained infiltrating cells (IC).…”

“…A few papers have dealt with the early microscopic changes in this organ after RSV infection, the most detailed studies being those of Keogh (12) and Prince (20). Many descriptive confirmations have appeared in the literature subsequently (3,6,26,29,30). Most investigators believe that the initial action of the virus is on the ectodermal cells which causes their proliferation with concomitant viral replication, and that the release of this virus subsequently infects the underlying mesenchyme and affects its proliferation.…”

Formation of Tryptophan-pyrrolase in Leukaemic Cells Incubated with RNA Obtained from the Spleen of Calf Embryo

“…Incubated with RNA Obtained from the Spleen of Calf Embryo By Sergio E sposito Over the last few years various writers have demonstrated the possibility of affecting the evolution of certain tissues by incubating them in a culture containing RNA (1,3,10). It has been observed, for example, that when an embryonic tissue is cultivated with the addition of RNA extracted from different organs, its own develop ment is orientated towards forms similar to those of the tissue which originally furnished the RNA (6,9,12).…”

Ribonucleic Acid-Induced Changes in Mammalian Cells

“…That the type of structure developed correlates with the tissue source of RNA indicates a response of the reacting tissue to a message carried directly by RNA or RNA-containing substances of the inducing tissue. Thus, on the cellular level, when a piece of the epidermal ectoderm of urodele gastrula is transplanted into the presumptive kidney area, the ectoderm contributes to the formation of extra kidney tubules3 and develops into muscle in the presumptive muscle area.4 At the molecular level, ribonucleoproteins (RNP) from different tissues were found to be capable of inducing the formation of muscle,', 6 blood,7 thymus,' and other tissues.2 Some two years ago, an examination of the effects of normal RNA on mouse ascites cells was initiated. After incubation with liver RNA, only 10 per cent of the transplanted ascites cells gave rise to tumors.…”