Genomic organization and expression of astroviruses and caliciviruses.

Astroviruses and caliciviruses are two families defined initially by their characteristic morphology. Many of these viruses have been difficult to grow in culture. Molecular biology has now provided a valuable insight into the nature of these viruses, and in many respects knowledge of genome structure now outstrips that of more classical virological features. However these advances have allowed a more detailed approach to virus classification and have led to the establishment of the Astroviridae as a distinct virus family.