Читать книгу Principles of Virology - Jane Flint, S. Jane Flint - Страница 61

Viruses are unique: often made up of nothing more than a nucleic acid molecule wrapped in protein, they parasitize the cellular machinery to produce thousands of progeny. This simplicity is misleading: viruses can infect all known life forms, and they comprise a variety of structures and genomes. Despite such variety, viruses are amenable to study because all viral propagation can be described in the context of three fundamental properties, as noted in Chapter 1: viral genomes are packaged inside particles that mediate their transmission from cell to cell; the viral genome contains the information for initiating and completing an infectious cycle; viruses establish themselves in a host population to ensure virus survival.

How viruses enter individual cells, their genomes are replicated, and new infectious particles are assembled are some of the topics of research in virology. These studies are usually carried out with cell cultures because they are a much simpler and more homogeneous experimental system than animals. Cells can be infected in such a way as to ensure that a single reproduction cycle occurs synchronously in every infected cell, called one-step growth. A full understanding of viral infectious cycles also requires knowledge of cell biology. Consequently, to reproduce the diversity of cells and architectures that are typical of tissues and organs, three-dimensional culture systems have been developed. In this chapter we begin with a brief overview of the infectious cycle, followed by a discussion of methods for cultivating and assaying viruses and detecting viral proteins and genomes and a consideration of viral reproduction and one-step growth analysis.