Talk:Nondisjunction

message: Nondisjunction is the failure of chromosome pairs to separate properly during meiosis or mitosis. The result of this error is that a chromosome(s) is lost (or gained). When a chromosome is lost, it is called a Monosomy, in which the gamete with the defect will have 1 or more chromosomes missing from one of its pairs. When a chromosome is gained, it is called a Trisomy, in which the gamete will have a set of 24 chromosomes instead of the usual 23. These errors cause Down Syndrome, Turner's Syndrome, Super-Male Syndrome (Extra Y-chromosome on last pair determining sex of the person). There many other Syndromes listed here.
A diagram of 2 possible occurences of non-disjunction in meiosis: (n means 1 copy of each chromosome [haploid cell])
                                                                  (2n means 2 copies of each chromosome [diploid cell])
       4n         (duplicated chromosomes in diploid cell)
     /    \       (non-disjunction occurs here)
   2n      0n
   / \     / \
  2n 2n   0   0   (Two gametes have one extra chromosome and the other 2 are missing a chromosome)
  
       4n          (duplicated chromosomes in diploid cell)
      /   \
     2n   2n
    / \   / \      (non-disjunction occurs here)
   n  n  2n  0     (2 Gametes are normal, but on the right side, one gamete has an extra chromosome, and the other is missing one)
Sources:
(Great place for in-depth insight on this subject)
Human Genetics 1
Genetics Home Referenceduh
I've changed the introduction to a more suitable definition MickeyK 22:21, 10 December 2006 (UTC)
thread_title: Article draft and notes

message: 1.  Is there anyway to prevent nondisjunction? 
2.  What are known risk factors of nondisjunction (e.g. maternal age, affected sibling, family history, ...)
lol  — Preceding unsigned comment added by 2806:263:C402:83D0:81F7:2394:5FAC:B24C (talk) 00:34, 23 February 2021 (UTC)
thread_title:  Risk factors and prevention

message: 1.  We could link additional articles at the bottom of ours to provide the reader with similar topics. Previte01 (talk) 03:20, 11 March 2014 (UTC)
thread_title: Further Reading

message: Wpeissner (talk) 02:47, 12 March 2014 (UTC)
thread_title:  References 

message: *Great progress on the article. The language is neutral, unbiased, and informative. The image you have is great! 
*In the current stage of the article, there is no lead section which comes before the table of contents and the first heading, so I would suggest to change the definition/terminology section into a newly created lead section for your next submission. 
*The content accurately represents cited sources. In the definition/terminology section, I would like to see sources 1,2,&3 come after each statement in which it belongs as opposed to after the entire paragraph. 
*The first sentence in the definition/terminology section could be a little confusing, so you could try to water it down a little for the reader and introduce terminology such as germ line cells or somatic cells. Also, since you state “failure of a pair or homologous chromosomes to separate in meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis ”, I would list meiosis 1, meiosis II, and mitosis in the same order in the next section of your article. It may also make sense to switch the order of the section headings diagnosis and molecular mechanisms so that we have read the mechanisms section prior to the diagnosis section. 
* I would love to learn more about the blastomere biopsy you reference in the Diagnosis section. Is this a treatment? If so, you could expand the section heading to be Diagnosis and treatment. You could also add a “See Also” section that links to other pages like trisomy or polysomy, but that could be redundant for terms you refer to directly in the article.
* This article has been improved and I look forward to seeing it progress. 
Ssumpf (talk) 13:35, 31 March 2014 (UTC)
replies: text: Thank you SSumpf for your critique and feedback.  The lead section of the article will constantly be updated as we add new information to the wiki page.  We have already started fine tuning it.  You bring up a good point for sources 1,2, & 3 coming after each statement.  We are also attempting at watering down a lot of the terminology as your have mentioned.  Several others have suggested this to us as well.  I am currently adding wiki links for appropriate words.  We will introduce new terminology as necessary.  I will continue to work on the diagnosis section because like you, I am fascinated by it as well.  Thanks again for your insight.  We will continue to improve with your help. Previte01 (talk) 02:09, 9 April 2014 (UTC)
replies: text: I love the improvements! I would love to see a picture of the diagnostic techniques, or better yet, a video! I wonder if video is going to be incorporated more in this online format in the future. --Ssumpf (talk) 03:00, 9 April 2014 (UTC)
replies: text:  Thank you SSumpf for your valuable input, we made re-organizations and added explanations as you suggested. Wpeissner (talk) 03:22, 9 April 2014 (UTC)
replies: text: Have you found any additional pictures for nondisjunction? I am having difficulty myself and was thinking about making my own. I would love to see more images for your article. I can relate with having difficulty watering down the language of the wiki articles. I think images help the visual learners out there. --Ssumpf (talk) 17:14, 21 April 2014 (UTC)
replies: text: Looks like you enlarged the image for nondisjunction - very interesting. I would still love to see more images before your final post, but the article looks good overall!Ssumpf (talk) 19:19, 3 May 2014 (UTC)
thread_title:  Comments from SSumpf 

message: Hi guys, great job so far! Here are some suggestions for you on what you've done, please feel free to contact me via email or my talk page if you have any questions about what I've suggested. Thank you!
* You need to write a lead to the article. Check out that link and look at some other articles to see what a lead should look like. Basically it's a summary/introduction to the article.
* Your citations in the first section are appearing for some reason below the first paragraph, try to make them appear at the end of the first paragraph instead. Ping me if you need help.
* You need a lot more wikilinks and should try to simplify the language a little more. Think about a smart 15-year-old with basic science knowledge reading this article.
`
I hope this helps you and can't wait to see what you do with the article. Best, Keilana|Parlez ici 16:12, 31 March 2014 (UTC)
replies: text:   Thank you Keilana for your advice.  I am currently working on wiki-linking and simplifying the language.  I get frustrated when I read certain articles and fifty percent of what I read goes right over my head.  I will use that experience to fine tune what we are working on.  As for the lead, we will constantly continue to update it.  I beleive Wpeissner was able to fix the citations problem you mentioned in your second bullet point.  Thank you for pointing that out.  Previte01 (talk) 02:23, 9 April 2014 (UTC)
replies: text:  Thank you Keilana, your comments are very welcome. We responded to all of your suggestions. The hardest parts seems to be the simplification of the language and terminology - the only thing that is worse than being complicated is being incorrect. But I definitely agree with you that the article should be easier to follow and we will continue working on that. Thanks, Wpeissner (talk) 03:18, 9 April 2014 (UTC)
thread_title:  Comments from Keilana 

message: * Great beginning outline to the article.
* I am confused as to whether you have made any actual changes on the article itself. It seems that on the article, you have a different layout on the article, than the outline that you have proposed on the article's talk page itself. If this is so, maybe it is time to move the outline to the actual article from the talk page, even though it may seem like a minor change, it will be less confusing to the peer reviewers.
* Having said that, the outline on the talkpage is much more in-depth and I like the direction that you are taking the article to. With its lead sections, mechanisms etc. 
*Since it is a molecular biology article, personally I think you could focus more on the science of the nondisjunction, the mechanism, the diseases/consequences associated with nondisjuction, more than dedicating a section to "history"
*Instead of having a separate section just for illustrations, it would be ideal to integrate illustrations throughout the article, rather than just one section. 
*Try to integrate the source of your information,(1, 2, 3)  right after the sentence/two that you have used it for, instead of the end of the paragraph.
*Lastly, I agree with Kleina that the language for this article is a little advanced for a non-scientist reader. If I was a potential parent of a patient who had no scientific background whatsoever, I would have a hard time understanding the content.
*Overall, you have laid an impressive outline of the article, so I am excited to see the turnout of it at the end.
CarpeDiem90 (talk) 22:34, 1 April 2014 (UTC)
replies: text:  Thank you for your suggestions CarpeDiem90.  I will update the talk page to make it less confusing for the peer reviewers.  You bring up a good point about focusing on the science of non-disjunction rather than the history.  Time willing, we will dedicate the appropriate efforts to both sections.  We will also be looking to incorporate our illustrations into the article itself rather than dedicating a section to them.  Several of your suggestions were also brought up by others and we are making those our top priority.  Previte01 (talk) 02:40, 9 April 2014 (UTC)
replies: text:  Hi CarpeDiem90, thanks for your feedback. I have started to make modification in favor of easier readability and corrected the formatting of references. Surely, illustrations will be distributed over the whole article. Maybe we should also reduce confusion on the talk b gradually remove topics from there once they have been added to the main page. Thanks again, Wpeissner (talk) 03:13, 9 April 2014 (UTC)
replies: text: The article is exceptionally well written! Great job guys!! CarpeDiem90 (talk) 01:41, 7 May 2014 (UTC)
thread_title:  Comments from CarpeDiem90 

message: The article is looking to be in great shape so far! I have reviewed your article and have some comments/suggestions that I hope you will find helpful. Please feel free to let me know if any of this information would benefit from further clarification.
Regarding the text, I appreciate the efforts that you have made to present each category clearly and that the categories are logically sequenced.  Part of the reason I think that your ideas presented are clear and easy-to-read is that the line lengths are limited to about 30-50 characters and spaces.  Your headers are simple and relate clearly to the text that follows.  The words and terminology are consistent throughout the document and the sentences are neutral and direct.
I really like the graphic that you have chosen to use that is located near the header.  It is helpful in explaining the text, easy to understand, and will be meaningful to the audience.  As you continue to develop your article and include additional graphics you may want to consider how to balance the “white space” with words and graphics.  This is probably something you are already thinking about but I thought I would mention it just in case.  
I like that you have included information about the researchers who are credited with discovering nondisjunction in drosophila sex chromosomes.  Would you want to consider giving that paragraph its own header “Discovery”? Just a thought :)
Also, I wanted to mention that I liked how you added an in-line reference for “Polar Body Diagnosis”.  Sometimes there just aren’t wiki pages available for scientific terms and so I think that it will be helpful to your reader to be able to easily click and link to a related article that further defines what PBD is. 
In the last paragraph “Molecular mechanisms” the last sentence refers to “segration control”.  I am not very familiar with “segration” and was wondering if perhaps you meant another term? 
As for the “readability” of this article, I wanted to mention that I ran a “Flesch-Kincaid Grade Level” analysis and it appears that it is written at the level of a college sophomore. Whenever possible, you may want to consider simplifying some of the more technical words.  The Flesch Reading Ease test results showed that your article received a 29.9 score.  This test rates on a 100-point scale and the higher the score, the easier it is to understand the document.  You may want to aim for your score to be between 60 and 70.  This is only a suggestion and it may be difficult to do given the topic of the article you are expanding.  
I have added your article to my “Watchlist” and I look forward to seeing new and interesting information and graphics added as the semester progresses. Great job! DHayes14 (talk) 16:42, 15 April 2014 (UTC)
replies: text: Hi DHayes14, thanks for your great comments and suggestions! I immediately corrected the typo "segration" which of course should have read "segregation". As for the readability: this aspect has also been mentioned by other reviewers, and we will definitely work on ease of reading again. But I also think that nondisjunction is a complicated topic and that readability should not preclude presentation of advanced topics. So maybe we should go for a readability "slope": starting easy with a well explained lead section and some commonly recognized examples (e.g. Down syndrome), but also including some more advanced topics in more elaborate language towards the end of the article? Thanks, Wpeissner (talk) 21:24, 15 April 2014 (UTC)
replies: text: Hi Wpeissner, I am happy that you found my comments to be helpful, tausend dank!  I do think that your article is looking great and I agree that nondisjunction is a complicated topic and you and your partner are tackling it well.  I like your idea of a readability "slope" and think that the article would benefit if you continued to proceed in that direction :)  DHayes14 (talk) 23:15, 15 April 2014 (UTC)
replies: text:  Hi DHayes14, thanks for your feedback! I was trying to make the language more clear and easier to understand, sometimes also by adding additional introductions or explanations. Are there still any sections that you find particularly technical or complicated? Liebe Grüsse, Wpeissner (talk) 00:53, 23 April 2014 (UTC)
replies: text: Your article, in its current state, is easy to read and doesn't appear to be overly technical.  Great work!  Were you planning on including any additional images, perhaps to the "Consequences" section? DHayes14 (talk) 14:11, 6 May 2014 (UTC)
thread_title:  Comments from DHayes14 

message: Hi, guys! Great job on your article thus far! Below you will find some comments/suggestions for your article:
General Comments
*The wording is unbiased, written from a neutral point of view, and easy to understand.
*Great use of wiki links throughout the article. 
*Images are well placed and are relevant to the article. The descriptions are beneficial to the reader.  
Introduction
*I think you have given a great introduction to nondisjunction. It's rather beneficial to the reader that you defined several terms in this section. Because you provide a wiki link for somatic cells, I don't think it's necessary to clearly define what they are; however, if you wish to do so, perhaps reword the sentence. Also, in the examples that you give, I would say "such as" rather than "like" and limit the list to two or three rather than listing several and adding etc. 
*As you proceed into other sections, I think you should stay consistent with the terms used. For example, if you are going to point out that eggs are in fact called oocytes, then continue to call them oocytes throughout the article or vice versa. The same applies with sperm and segregation. 
*You are careful to point out who is credited with discovering nondisjunction. I agree with Dhayes in that you may want to consider adding a Discovery section in which you briefly outline the experiments that lead to nondisjunction discovery.
Three types of nondisjunction
*The article is about nondisjunction, so you could shorten the name of this section to simply "Types."
*Also, I would suggest providing a wiki link for the term "bivalent."
*According to our ambassadors, we do not need to provide a citation back to back in the same paragraph. Rather, we can simply put the citation at the end of the paragraph. I noticed that Reference 5 was cited back to back in the Meiosis I section.
*Reference 5 is a wonderful reference, and I can understand why you use it throughout the article. It provides various definitions and images for nondisjunction. This reference gives a lot of information regarding the possible causes to aneuploidy in Meosis I as well as II. I think it is important to clarify in the article that failure of segregation in Anaphase I may occur via three ways and clearly define the mechanisms of MI, homologue, and classic nondisjunction. These mechanisms are discussed in Figure 4B as well as the text following the figure in Reference 5 Currently, the way it is written ("Failure of segregation of a bivalent in Anaphase I goes by three names:...") sounds like they are all synonyms for one mechanism of nondisjunction. 
*The mitosis section could be split into two separate paragraphs rather than one long one.
Molecular mechanisms
*Perhaps you should change the title of this section to Prevention since it is discussing ways the cell inhibits nondisjunction. Initially, I thought this section was pertaining to molecular mechanisms of nondisjunction rather than prevention. 
*According to Reference 11, SAC occurs in mitosis as well as meiosis; however, the mechanisms of action are slightly different for each. I think this should be clarified. 
Consequences
*I don't think you need to redefine aneuploidy since it was already defined in the introduction. I like the fact that you defined the different types of aneuploidy and tied that into your discussion of the different types of syndromes. I also liked the fact that you discussed whether or not the syndromes were viable. 
*Is there a typo for sex chromosome aneupoloidy? Rather than "sec chromosome," is it meant to be "sex chromosome." 
I noticed on your outline of the article talk page that you initially planned to include a treatment section. Although most of them are incurable, you could lifestyle changes they may have to make. Or rather than discussing treatment options, you could include a research section to discuss ongoing research relevant to curing nondisjunction. Keep up the good work on the article, and please let me know if you have any questions! Kneal0627 (talk) 18:19, 24 April 2014 (UTC)
thread_title:  Comments from Kneal0627 

message: I am still confused by the meiosis I and II sections.
where you said "save-guarding" you likely meant safe-guarding.
You may wish to link to advanced maternal age, spontaneous abortion, mental retardation
I it is unclear that "45, X0 karyotype" is the same as "loss of an entire X chromosome". In this sentence number of fetuses does not match the verb:  "fetuses are aborted" not  "fetuses is aborted".
sec chromosome should read sex chromosome.
Graeme Bartlett (talk) 11:18, 26 April 2014 (UTC)
replies: text: Hi Graeme, thank you very much for the helpful comments. We will be sure to check / correct all the details you mentioned. Thanks, Wpeissner (talk) 18:00, 29 April 2014 (UTC)
thread_title: comments from Graeme

message: Hi! Your article is easy to understand and the images that you  have are placed correctly and relevant to the topic. Some suggestions:
*Link bivalent in the Meiosis I section
*Meiosis, mitosis, aneuploidy, and a couple other words are linked more than once. After the initial usage and linkage, you don't have to link them anymore. 
*I don't think you have to write "Three types of Nondisjunction". I believe "Types" would be sufficient enough.
*Perhaps more images should be added to the Consequences section. I think it's great that you guys listed out all of them, and how they are formed, but it does seem to be lacking some detail and/or images. 
*Images pertaining to the Meiosis I and Meiosis II types of nondisjunction should be added if you have time. 
*Image pertaining to the molecular mechanism may be helpful in its understanding.
Overall great job so far! Gkaltam (talk) 17:57, 27 April 2014 (UTC)
replies: text: Hi Gkaltam, thanks for your input! I guess I got the main message: More images! We're working on it... Cheers, Wpeissner (talk) 18:13, 29 April 2014 (UTC)
replies: text: Great progress on your article, Wpeissner!Ssumpf (talk) 01:57, 30 April 2014 (UTC)
thread_title:  Comments from Gkaltam 

message: Substituted at 01:27, 30 April 2016 (UTC)
thread_title: Assessment comment