Table 1.

Recent examples of biological implications of quasispecies

Virus	Observation	References
Foot-and-mouth disease virus	Altered cell tropism of the minority of the mutant spectrum	Jackson et al., 1996, Sa-Carvalho et al., 1997
	Dispensability of essential motif	Martínez et al. (1997)
Vesicular stomatitis virus	Different ability of viral clones to induce interferon	Marcus et al. (1998)
Feline calicivirus	Evidence of antigenic evolution in vivo	Radford et al. (1998)
Hepatitis C virus	Response to IFN related to quasispecies complexity	Le Guen et al. (1997); Pawlotsky et al. (1998, unpublished data)

Additional examples can be found in Domingo (1996)and Domingo et al. (1997).