Talk:Bacteriophage/Draft

Approval area

David Tribe has nominated the version dated 11:47, 20 May 2007 of this article for approval. Other editors may also sign to support approval. The Biology Workgroup is overseeing this approval. Unless this notice is removed, the article will be approved on May 24, 2007.

David Tribe has made only typographical adjustments to the page and is not an author. However he is expert in the field and teaches senior year college courses in this topic. But the author is more expert than David Tribe

URL pointer first set at http://en.citizendium.org/wiki?title=Bacteriophage&oldid=100105406 18:09, 16 May 2007 (CDT) URL pointer updated http://en.citizendium.org/wiki?title=Bacteriophage&oldid=100107557 David Tribe 03:06, 20 May 2007 (CDT) URL updated http://en.citizendium.org/wiki?title=Bacteriophage&oldid=100107653 David Tribe 06:49, 20 May 2007 (CDT)

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The images within should be in the public domain. I was given the photos by colleagues from whom, if it came to that, I can request permissions. I can't immediately verify the false color T4 photo's provenance, so I removed it.

I've had to delete most these images:

• Image:Phage_lifecycle.gif
• Image:Lambda.jpg
• Image:T-_4_Phage.gif
• Image:Phage.gif

because of lack of source documentation for them. I hate doing that. If someone gives me a list of what exact images are still needed, I'll make an effort to find replacements we can fully document. The above four could in a snap be undeleted, too, if the source and copyright status can be verifiably documented. Stephen Ewen 15:39, 16 May 2007 (CDT)

Scientists comments on first reading

• You begin with "In 1896, M. E. Hankin reported that something in the waters of the Ganges and Jumna rivers in India had marked antibacterial action against cholera and could pass through a very fine porcelain filter (Adhya and Merril 2006)." Yet, you do not mention what the significance of that is, and you do not take adavantage of weaving a little mystery here. I happen to know, because my mother as a young woman was a cook in "Mr.Stanley"'s household, that the first virus was not identified then and that a notable characteritic for the early virologists was this ability to pass through porcelain. I do not think this is universal knowlege.

• This article looks great and I am probably as good non-expert person to review it as anyone, I am going to quote a sentence that confuses me.

"One of the densest natural sources for phages and other viruses is sea water, where up to 107 phages per ml (or, at least, of virus-like particles)(Wommack & Colwell 2000). Whitman et al. (1998) argue that there are between 1030 and 1031 prokaryotic cells on our planet." ?????Nancy Sculerati 18:28, 16 May 2007 (CDT)

• Question: quoting the text:"Twort's work was interrupted by the onset of World War I, and when he returned to the Brown Institution, he spent the rest of his career trying to grow bacteriophages on artificial medium." Please include the punchline! He failed I take it because he didn't try to grow them in bacteria? Or what?Nancy Sculerati 18:35, 16 May 2007 (CDT)

• "Duckworth (1976) provides a historical account of the discovery of bacteriophages." This is a non-sequitor. Perhaps you should put his article or book under further reading and place this descriptor next to it. Nancy Sculerati 18:32, 16 May 2007 (CDT) Oh, I see- the next part is a summary of his writing? I don't know this history, if I did I would help you, but I suggest that you simply tell the story rather than give a list of events. Why are thses events important?

• Similarly, with the list of fmilies, the classification. I think what is needed here is an expalanation of how the taxonomy works, what features are used to classify the phages and why are these features important. Maybe it was a historical thing, I don't know, but some concepts need to be conveyed here. And then I suggest that either you make a catalog of the families that are presently in this list and link that to the article, or you make a table of this list that is not just a list but is arrayed in a manner that conveys the concept of how bacteriophages are classified.Nancy Sculerati 18:44, 16 May 2007 (CDT)

• Third paragraph: If one phage per cell is assumed, I would expect the argument to arrive at the same number of phages as cells, but the number of cells is given as $10^{30}$ to $10^{31}$ and the number of phages as $10^{30}$ to $10^{32}$. I would expect "conservatively" to mean that the number of phages is if anything underestimated; maybe it was intended to mean the opposite here but I don't find that clear. --Catherine Woodgold 20:39, 20 May 2007 (CDT)

Non-scientists comments on first reading

• The historical account of the discovery of bacteriophages strikes me as lacking. It might be very interesting to get a bit inside the heads of the people who made these discoveries, to understand what drove them and how they viewed their successes and failures. Choice quotes from memoirs, etc, is a great technique by which to do that. Stephen Ewen 04:37, 17 May 2007 (CDT)

• The meaning of "This specificity means that a bacteriophage can only infect certain bacteria bearing receptors that they can bind to, which i.e. determines the phages hostrange" is unclear to me. Believing the problem is only one of wording, and hoping I changed no meaning, I reworded it to, "This specificity means that a bacteriophage can only infect bacteria that bear the certain types of receptors that they can bind to, which determines the phages hostrange. Stephen Ewen 18:49, 16 May 2007 (CDT)

fixed it, I hope.Nancy Sculerati 11:24, 17 May 2007 (CDT)

Excellent, Nancy. I completely and without effort grasp your re-wording and minor expansion. Stephen Ewen 13:42, 17 May 2007 (CDT)

• The section Major discoveries with phages might be better if explained in a narrative. Stephen Ewen 03:49, 17 May 2007 (CDT)

• The section "Structure": 1) This section would be better narrated as well, I think. 2) it would be helpful if I had points of reference with which to compare "from 24-200 nm". Since people learn using contrasts, compare this size with one or two common things from microbiology, and then how many would fit on a pin-head or a period, for example. 3) The statement "In the more complex phages, like T4" seems to lack context. Perhaps mention in the Intro or somewhere that phages range from the simplest, e.g., x, to ones like T4. Better, expand the classification section to show how they compare, and to contrast the features that more complex phages have that simpler ones do not. Stephen Ewen 04:20, 17 May 2007 (CDT)

• The section "Release of virons": "Host lysis is usually achieved through an enzyme called endolysin which attacks and breaks down the peptidoglycan, which is....". If a peptidoglycan can be described in a few words, it'd be helpful. Otherwise, I am lost on that point. Stephen Ewen 04:20, 17 May 2007 (CDT)

Congratulations

I like it, hope my copy edits and minor style tweaks are OK. I stuck at the lead with an unanswered question If we assume that there is one virus for every prokaryote host.... Why would we assume this exactly?Gareth Leng 09:38, 17 May 2007 (CDT)

On this point, there are number estimates on phage numbers in the oceans that indicate virus (phage) numbers exceed bacterial number. Couldn't this point be leveraged off these actual data rather than an assumption? David Tribe 21:24, 17 May 2007 (CDT)

Congratulations and apology

I made a number of additions, and some revisions, that -to me-make the article more of a narrative story. I read the references (what good ones!) supplied to do so, and hope that these changes have not hurt the accuracy of the article. Therein lies the "apology". Please change and revert without question anything that has impaired the sense of the article rather than clarified it. Nancy Sculerati 08:12, 19 May 2007 (CDT)

minor point (that I am too lazy to look up myself)-Tectiviridae has no descrfiption in the list.Nancy Sculerati 05:18, 20 May 2007 (CDT)