Coronaviruses and arteriviruses have emerged as major virus families relevant in ani mal and
human health. The order Nidovirales which includes the Coronaviridae and Ar teriviridae was
recognized by the International Committee for the Taxonomy of Viruses (ICTV) in 1996 based on
the striking features common to the two virus families. In accord ance with this decision the
organizers of the coronavirus meeting held every three years since 1980 invited colleagues
working with both virus families to attend the VIIth Interna tional Symposium on Coronaviruses
and Arteriviruses held in Segovia Spain in 1997. This symposium provided a stimulating forum
for assessing the progress made since the last of the scientific meeting which was held in
Quebec Canada. This volume is a collection papers presented at this symposium attended by 170
scientists from academia and industry. Virus Entry has been reviewed in the first section of
this volume by studying the interaction between mutants of virus receptors and coronavirus
spike protein. The neutrali of virus by soluble receptors has been used to study this
interaction. Interestingly zation the evolution of virus-receptor interaction leads to
interspecies transfer of coronaviruses. Construction of chimeric aminopeptidase the receptor
of group I coronaviruses has been useful in the identification of the virus-binding sites for
coronaviruses of the porcine ca nine feline and human species. The progress in this area has
revealed that the feline ami nopeptidase is a receptor for all group I coronaviruses.
