Page 305 - The Veterinary Laboratory and Field Manual 3rd Edition

274 Susan C. Cork and Roy Halliwell

Figure 4.36 Phylogenetic Tree of a total of over 180 partial σC gene sequences of avian reovirus. The
analysis included sequences obtained from the GenBank. Vaccine strains are shown in a bold red colour.
The tree shows several clusters of avian reovirus and most of the sequences are far from the sequences
of the avian reovirus vaccines. This raises the question whether vaccine induced immunity is protective
against the disease induced by these diverse avian reo viral strains. See also Plate 21. Source: Victor
Palomino-Tapia, University of Calgary, Canada.

The power of this type of analysis is that tive in that they are not open to interpretation in
it allows the digitalization of strain type. This the same way as banding patterns on gels or bio-
can be stored readily on databases and is hence chemical tests can be. A number of databases for
highly transportable allowing easy comparison an increasing number of organisms have been
of strains from around the world. The other established allowing comparison of strain data
advantage is that these sequence data are defini- from around the world.

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