Picorna-like viruses

[Ed Rybicki]

> In Ed Rybicki's posting musing about picorna-like virus evolution,
> he claimed that plant picorna-like viruses are not similar in sequence to
> anything else.
>
> This is incorrect.  Turnbull-Ross et al. show by dot plot analysis (Fig. 3, J
> Gen Virol 73:3203 1992) a clear similarity of the sequence of the polyprotein
> of parsnip yellow fleck virus to the sequences of human rhinovirus 14 and
> hepatitis A virus polyproteins.  The polyprotein sequence of rice tungro
> spherical virus is also related to those of the animal picornaviruses.

Related, yes - closely related, no...in fact, only marginally closer than
potyvirus sequences.  What I was trying to get at (and missed, by
overstating the case) was that the plant viruses are VERY distantly
related to each other, and to anything else - meaning they should perhaps
be in different sub-families from each other, with mammalian
picornaviruses in yet another sub-family as these are all more related to
one another than any is to the plant viruses - in a larger family
Picornaviridae.  Putting up two genera of a new family strikes me as being
horribly premature, given the genomic and structural similarities of the
plant, insect and mammalian picornaviruses and -like viruses, compared to
(eg) caliciviruses and mammalian picornaviruses.

But I thank Ulrich for straightening out the discussion...!  You meet good
people in this newsgroup - contribute! discuss! get bionet.virology
humming!

  ____________________________________________________________________
 | Ed Rybicki, PhD             |       "Lord, won't you buy me        |
 | (ed at micro.uct.ac.za)        |                                      |
 | Dept Microbiology           |         A Mer-ce-des Benz..."        |
 | University of Cape Town     |                                      |
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 | 7700, South Africa          |           - Janis Joplin             |
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