Take the 2-minute tour ×
Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

Wikipedia says Caliciviridae Family. My notes say that Norovirus includes the following

Noroviruses

  • Norwalk-like viruses
  • Caliciviruses
  • Astroviruses and some small gastroenteroviruses

which is a larger definition including at least two families than the Wikipedia definition. I think

  • Caliciviruses $\subset$ Caliciviridae
  • Astroviruses and some small gastroenteroviruses $\subset$ astroviridae

so the note is taking subsets among different families and classifying them into abstract class called Noroviruses.

Extension based by Chris' excellent answer.

Criteria of Noroviruses

  • (+)sense ssRNA viruses
  • Structure and replication:
    • 1) only (+)sense ssRNA,
    • 2) simple nucleocapsid viruses,
    • 3) only viruses transmitted by fecal-oral route,
    • 4) size about 30 nm in diameter.

and then final classification of Noroviruses by these criteria

Noroviruses

  • Noroviruses $\subset$ Norwalk-like viruses ($\subset$ F. Caliciviruses)
  • Some Astroviruses ($\subset$ F. astroviridae) and some small gastroenteroviruses (what?)

which, however, does not make sense since Caliciviridae $\not\subset$ Astroviridae. I do not understand what is the point of referring to the viruses by the sentence

Astroviruses and some other round/small gastroenteris viruses

which are not part of Astroviridae.

Which viruses of Caliciviridae are similar to Astroviruses that are apparently round and small gastroenteritis viruses?

share|improve this question
    
I don't understand your new question. What do you mean with understand? What is the purpose of your work? –  Chris May 29 at 21:05
    
@Chris Thank you for your comment! I included the criteria of classification for Noroviruses. –  Masi May 29 at 21:27
    
You want to know how the Norovirus was selected taxonomically? –  Chris May 29 at 21:46
    
@Chris Yes, I think so. In above definition, noroviruses include some viruses from Caliciviruses, Astroviruses and some other small gastroenteroviruses. –  Masi May 30 at 4:47
    
Which doesn't make sense. Ciliciviruses include Noroviruses, but not Astroviruses. The only belong to the same group. –  Chris May 30 at 7:04

2 Answers 2

up vote 6 down vote accepted

You are mixing different things here: Virus are grouped based on their genetic material (dsDNA, ssDNA ssRNA and so on) into several groups (see here for details), then grouped into families, subgrouped into a genus and then into species.

So it is: Group > Family > Genus > Species.

What you have here are are different positions in this classification. The names you mention belong all to the same tree:

Group: IV ((+)ssRNA-Viruses) > Family (Caliciviridae) > Genus (Norovirus) > Species (Norwalk Virus).

The Astrovirus belongs into the same group, but then form an own family. To answer your question: No, since the Norovirus forms its own genus in the caliciviridae family.

share|improve this answer
    
Last sentence - do you mean genus (not family)? –  Alan Boyd May 29 at 18:23
    
Yes, you are right. Thanks, I corrected it. –  Chris May 29 at 19:33
    
Thank you, Chris, for your excellent answer! I have been completely confused by different naming systems that have been used. Besides those two systems, there seems to be also some conventions. I am trying to understand what is the initial point of making a abstract entity "Noroviruses" and including some viruses from different families into it. –  Masi May 29 at 20:59

I take NCBI's taxonomy any day over what wikipedia says. According to NCBI Caliciviridae includes Lagovirus, Nebovirus, Norovirus, Recovirus, Sapovirus, Vesivirus, Secalivirus, etc. For example:

Viruses; ssRNA viruses; ssRNA positive-strand viruses, no DNA stage; Caliciviridae; Norovirus; Norwalk virus; Chiba virus

Anyway, due to the absence of universal phylogenetic marker genes, viral taxonomy is mostly based on capsid shape and isn't thus very accurate..

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.