Animal Viruses and Embryos

Abstract

This review illustrates the thesis that the concepts and techniques of animal virology may provide effective measures for analyzing genetic and epigenetic relations in developing cells. The authors discuss first the effects of introducing nucleic acid in the form of virus on the subsequent history of a cell, paying particular attention to the modification of patterns of differentiation and growth by tumor viruses. The question, can viruses be used to study the origin of differences in cell specific properties, is approached by examining the pathologic effects of viruses on embryos. The role of viruses as causative agents in congenital malformations is considered. Viruses are not only agents for modifying the course of development and for detecting when differences arise in cells. Experiments from several disciplines are discussed which focus on the concept of recombination between vertebrate somatic cells. Can intercellular transfer of subcellular units modify patterns of synthesis in embryonic cells. Among the examples treated are the transfer of enzyme forming capacity by epigenetic recombination in bacterial and vertebrate cells; transfer of antibody forming capacity; the selective uptake and exchange of sub-cellular particles in the chick embryo; and the use of viruses to facilitate transfer of information between vertebrate cells. Finally the application of recent genetic findings, arising from virological and other microbiological studies, to the ontogeny of one class of specific proteins, antibodies, is explored.