Thomas G Research Paper

Symbiotic relationship between Euprymna scolopes and Vibrio fischeri
Thomas Gates
For over a decade, the symbiotic relationship of (between) Euprymna scolopes and Vibrio fischeri has been studied extensively. This research has brought about much knowledge and many new insights into the topic of animal-bacteria symbiosis. It is able to provide such knowledge because the relationship is very easily studied and is also very easily controlled in laboratory settings(this last sentence is stated awkwardly) (also, I personally would either get rid of the "very's", and either substitute a new word or take it out). (I would like to see a little more background maybe, or even a better transition to help state where your paper is going) (Do you think you could mention a little bit more of the research done among Euprymna and Vibrio)
Vibrio fischeri is a bioluminescent bacteria that colonizes a “light organ” of the Euprymna scolopes, or bobtail squid. The bioluminescence of the light organ is believed to use counter-illumination as an anti-predator response. It does this by distorting its shadow with the ventrally located light organ. (What are the benefits for the V fisch?) (1) In more recent years, a study was performed to try and help determine better (consider deleting better) the morphology of the light organ and also to look for changes due to colonization of the Vibrio fischeri. The study discovered new morphologic features than what had previously been thought (Consider: The study discovered new morphologic features than previously known) (What kind of changes were involve). A light organ of a bobtail squid contains two pairs of three crypts that are symmetrical to each other. Each crypt contains the same features although the crypts themselves do vary in size and shape. The first crypt is the largest and most complex of the three crypts where as the third crypt is the smallest and least complex** and the second is in between both crypts for size and complexityredundant (Consider to reword a little bit because like mentioning to many numbers can confuse the reader). The features that each crypt shares are the duct, antechamber, bottleneck, and the deep crypt. The duct is the most lateral segment of each crypt. It is tube-like and ciliated and extends medially to the most superficial pore. The antechamber is medial to the duct and is a chamber that precedes the deep crypt. Next comes (Next is the bottleneck, a short, narrow..) the bottleneck, it is a short, narrow connection between the antechamber and deep crypt. The last feature is the deep crypt, which is the this is farthest away from the pore and the largest of all the features. Another important feature of the light organ is (the ink sac.) that t (T)he ink sac that will actually grow towards and around the light organ and can function as an iris-like structure in order to control the light emitted. (2) If you decide to continue to use this paragraph, it needs to come MUCH later in the paper. You have yet to establish a clear relationship between the bacteria and the squid. A life cycle with an accompanied diagram would be wonderful right after the introduction along with how this specific relationship between the Euprymna scolopes and Vibrio fischeri relates to a a much larger picture).consider using something other then "the" for beginning your sentences. I like the explanation in this paragraph but you should consider writing more about the squid and the bacterias so the reader can understand a little bit better the main idea of your paper
In Euprymna scolopes’ natural habitat Vibrio fischeri makes up only about 0.1% of the bacterial cells in the water. Yet the light organ is able to use several mechanisms** to its adavantage to ensure readily colonization by Vibrio fischeri. The squid secretes mucus from the ciliated cells in the light organ in order to form aggregations of Vibrio fischeri. Even when E. scolopes isare** put in Vibrio fischeri free water, but (and has no other variety…) has other variety of gram-positive and gram-negative bacteria even other Vibrios, it is*they are** able to stay aposymbiotic(unclear sentence) Reword. It is still yet to be fully determined though (delete though) on how the light organ is able to ( distinguish Vibrio fischeri than other bacteria and will out compete other bacteria that aggregate in the mucus.) fully distinguish better Vibrio fischeri and the other bacteria and even (and how it) out competes other bacteria that aggregate in the mucus. There are some hypotheses on why it is able to do this. It is believed (suggested) that it is not the mucus that is really selecting for the V. fischeri since other bacteria can aggregate in it but maybe the V. fischeri is able to change the molecular composition of the mucus so it creates a biofilm that only favors it (Id like to know more about this) What is it??. There is a ton of "it" in this sentence. I would say. It is suggested that the selection of **(for) V. fischeri is related to a change in the molecular composition of the mucus, creating a biofilm that favors V. fischeri only.)** (3) Also, the light organ itself has two (ciliated) appendages on either side of it that are ciliated that (delete that, use and) lead down to pores that lead(ing) (you should probly use another synonym for "leading" here) , into the crypts. One study has shown though (One study has shown, however, that..) that outer membrane proteins do play a role in colonization of the light organ. OmpU (outer membrane protein U) is an important protein in V. cholerae when it is acting on a host so scientists wished to see if V. fischeri used similar means of acting on E. scolopes. (What is meant by "acting" here?) What was found out is (Studies reveal…) that OmpU also plays a role in the colonization of a light organ. OmpU helps the V. fischeri adhere to the mucus and endothelial tissue of the light organ. Although the study did test a mutant strain that did not express OmpU, it and found that it doesn’t easily colonize the light organ, but is capable of but it does not trigger physiological changes as well as V. fischeri that does express OmpU, but when both OmpU expressing V. fischeri and non-expressing are in an aggregation it was shown that OmpU can be shared and can help non-expressing bacteria to colonize the light organ Try to reword or write two sentences.(Run on, consider using more abbreviations, periods, etc., also, try not to use "it" so much…this sentence needs to be broken into about 3 sentences) (4) A feature of V. fischeri that helps colonization is the fact that it has flagellum on it to allow for greater motility. (5) The light organ also has a more physical aspect that might help for (aid in) colonization as well. Approximately every half-second the light organ will pass about 1.5 uL of seawater through itself. With V. fischeri only making up 0.1% of the seawater this calculates out to mean that about one cell in 500 mL passes through the light organ. (6) This maybe a very small number but it is possible that this small amount might be able to still communicate with the light organ in order to bring about needed changes. (can you talk about the physiological changes that the light organ undergoes that you mentioned in your paper presentation, I think it would be important here.)
The mechanisms of (delete of) that help the colonization of the light organ are very efficient at making sure that it will become colonized as some studies have shown. One study wanted to see what was (focused on) the lowest number of V. fischeri that it would take to be able to still successfully colonize the light organ. The study found that at 250 cells of V. fischeri per squid, 50% of them would become colonized within three hours. When the number of cells was dropped to 100 cells per squid, colonization became rare. As the number cells became closer to 1000 cells, colonization began to reach around 100%. The squid that wereSquids exposed to a higher number of cells became luminescent sooner than those exposed to lower number of cells. As the inoculum increased to around 36,000 cells per squid a maximum was reached and the squid did not end up being colonized any faster. The important thing (aspect) from this experiment is that all of the squid did eventually become colonized. This indicates that a wide range of doses of V. fischeri can initiate colonization. (7) Also It has also been found that V. fischeri exists in two different forms What different forms??. They have been categorized into visible light (VL) and non-visible light (NVL). What studies have found is that the light organ is colonized by the NVL and that it can actually out compete the VL up until the VL concentrations are ten fold that of the NVL. Although scientists do not know why this is possible, they speculate that the VL V. fischeri is actually symbiosis incomplete. (can you explain symbiosis incomplete)(8,9)
(The following statement is VERY informal and not necessary. This paper should go in a more formal direction, and the details of this paragraph need to be moved closer to the introduction of the paper.) **So far this paper has discussed many aspects of the symbiotic relationship between E. scolopes and V. fischeri, but so far it has not mentioned probably the most important aspect and that is how does V. fischeri give off light. Before things get too** specific, the general overview is that V. fischeri uses a process known as quorum sensing. By definition, a quorum is a minimum number of people that must be at a meeting in order for it to take place. The same is true with quorum sensing. In order for V. fischeri to be able to give off light there must be a certain number of bacteria or a certain population density in order for this to happen. The bacteria are able to communicate with each other to know when it's time to start by using chemicals known as auto-inducers. The most common auto-inducer used by other bacteria and V. fischeri (switch other bacteria and V. fischeri around) is homoserine lactone, or HSL Can you explain what is homoserine lactone?. (10) The actual system that is used by V. fischeri for the signaling of its bioluminescence is a very complex process. V. fischeri contain(s) proteins known as lux proteins that help with transcription and translation of the lux operon, the series of genes that encodes of luminescence. LuxI and Lux are two of the important proteins that act upon the lux operon. LuxI is responsible for the production of the auto-inducer HSL. As the levels of HSL become high enough the translation of luxR can take place and it is what will , which directly lead (s) to the expression of the light emitting genes. (10,11,12) It has also been found that the lux proteins play an essential role in the colonization of the light organ. If there is a problem with luxA, luxI, and luxR, the bioluminescence of the light organ will be less than 0.1% of a normally populated light organ and cannot maintain the normal population that the light organ requires. The most interesting result of mutant strains of V. fischeri is that when the lux proteins are not expressed properly, than the light organ fails to express certain traits such as epithelial swelling.(11) (how can the organ sense this, is there some kind of response to the lux proteins?)

Thomas: You should think to add more information on the introduction so the thesis statement can be well explain. Also you have very good information but you should think to write more about the relationship between the animals and the bacteria. Think always about the reader and that there are some words that the reader can possibly not understand. There is some parts that don't flow, like you try to explain different things at the same time… Once again you have good information just try to organize it a little bit better and your paper will be great at the end…
-Thomas, paper was well written, but ended without a conclusion. I think it would be good to go into more detail about the animal-bacteria relationship, mutualistic vs commensal?
Thomas: For the introduction add more information about why this relationship between the squid and the Vibrio fisheri is important, such as about "normal fora" and how this research is helpful to all people. Also so overwritting (using too many words). I also would suggest a conclusion wrapping up the importance of the relationship btw the squid and the Vibrio fishers for: the bacteria, the squid, scientists, and average Joe walking down the street who doesn't know a bacteria from a dust bunny!
I would like to see this paper move in a more formal direction. A good start with a lot of detailed information, but the flow just isn't working for me. I know we made outlines for class, but make an outline of your paper RIGHT NOW where it is, and see how your paper flows. I think you'll find that you haven't given background information before you jumped into the details, and your introduction is lacking some substance.
Thomas-I love the topic of the paper…however, i would also like to here maybe why the bobtail squid does not reject the V. fischeri or does immunology even play a part in this topic…also, try to read over it a couple more times and try to restructure some sentences in order for the paper to flow better)

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