Talk:Karyogamy

Proposed improvements

We will be working on expanding this stub as part of a Johns Hopkins University course in Molecular Biology.

We propose the following outline and will begin editing within the next few weeks.

Working Outline

1. Overview (per Wiki standard)
2. Role of karyogamy in sexual reproduction
3. Role of cytoskeleton in karyogamy
4. Biochemical components necessary
5. Potential problems
6. Implications in human disease

Sarah Facci (talk) 01:45, 22 October 2013 (UTC)

We need to differentiate between spindle pole bodies (yeast/fungi and plants) and centrosomes(animals). How do you want to address the differences? Should we make separate sections for fungi and animals or should we address both of these under cellular mechanisms? I guess the answer to that rests on whether there are other differences in karyogamy between the two groups, like perhaps in the implications for disease? Sarah Facci (talk) 00:40, 31 October 2013 (UTC)

This week (Nov 20-26) we need to:

• add information about gamete formation in haploid eukaryotes
• substantially flesh out the section on cellular mechanisms, especially the section on actual karyogamy (Don, it'd be great if you could help me with that section)
• add illustrations
• add information to the lead from mammalian (higher eukaryote?) fertilization
• add information about somatic diploid formation and its purpose (I can work on that)
• add more to mammalian fertilization section
• research whether there is an implication in disease for fungi/yeast/algae

I think we are finally clear that karyogamy applies only to haploid eukaryotes, and is called something different in diploid organisms such as plants and mammals. We need to make sure the text reflects that. Sarah Facci (talk) 07:35, 23 November 2013 (UTC)

In reviewing many of the comments by the reviewers, it's clear that we need to reorganize a bit in an effort to make the whole subject more approachable. If you don't mind, I'm going to "be bold" and take a shot. If we don't like the result, we can roll back to the previous version. Don Brown (talk) 14:07, 26 November 2013 (UTC)

Good job "being bold" but I think the categories sound too general. "Certain organisms" is overly broad, and "Overview" seems like it should just be part of the lead. I was hoping to get more opinions from reviewers about whether our structure was still confusing after our edits this week (since we added a lot) and then see about reorganizing. Thoughts? Sarah Facci (talk) 23:59, 1 December 2013 (UTC)

I agree that the names are too general, especially "Certain organisms". Should we rename it to make it clear that karyogamy applies to haploid organisms? On the overview, I'll look back at the guidelines for the lead. My sense was that the lead should be pretty short and just give the big picture, so it seemed like going one level deeper made sense. I'm certainly not married to the approach though. Don Brown (talk) 19:44, 2 December 2013 (UTC)

Hmmm, I think there is a lot of repetitive information in the lead and the overview. It seems integral to the topic that it is important in haploid eukaryotes, so I would probably leave that in the lead too. I see that you explained some things further though which is good. Let's see what some of our other reviewers think and we can edit again next week. Sarah Facci (talk) 19:59, 2 December 2013 (UTC)

I spent way too much time looking for more information on somatic diploids in fungi before stumbling onto a common one, Candida albicans. I added mention of it to that section as well as a nice reference. I also added a little "See Also" section. It's hard for me to see where else to take this article without going way off into the weeds someplace. Hopefully this will be useful to someone wanting to get a sense of what karyogamy is and give them a jumping-off point to more information. Thanks for all the hard work you put into this. Don Brown (talk) 17:57, 12 December 2013 (UTC)

Comments from grabriggs

This article is well written in my opinion so far. It is written at a high grade level, but a technical subject like this may need that level for explanation. The references look sound. Good job finding texts to go over the basics of the process. The lead mentions sexual reproduction and a subsequent section addresses it for fungal species. However, the lead also mentions organisms that lack sexual cycles forming somatic diploids. I wasn't sure if this is the same process or a different one. Also, is this process unique to fungi or do all eukaryotes use it to form a diploid egg after fertilization? Another subsection may be useful to differentiate the two, or describe in the lead. Cellular mechanisms section seems to end abruptly and could use some expansion, but I see you are already addressing that. Additional topics are mentioned in the outline and should add greatly to the article. After describing how the process is supposed to work it is interesting to see how malfunctions in the system effect the organism's health and fitness. Grabriggs (talk) 21:48, 2 November 2013 (UTC)

Hi Graham, I added the section on somatic diploids and am working on expanding it this week. Sorry for the confusion... it was in the plan but hadn't happened yet. and Don is working on the section to compare it to higher eukaryotes! Sarah Facci (talk) 21:56, 10 November 2013 (UTC)

The improvements look great! You have a good backbone to build on now. The comparison to mammalian fertilization is easy to understand and the mechanisms sections are coming along. Keep up the improvements! Grabriggs (talk) 02:02, 14 November 2013 (UTC)

The addition of the pictures looks good and your narrative has made huge strides. Looking great! Grabriggs (talk) 02:01, 26 November 2013 (UTC)

This looks excellent! The intro has been re-written and is very easy to understand, written at a good level for non-scientists. You have expanded multiple sections and it flows very well describing the topic in depth. It looks like you are working on the last section or two, but this is a huge improvement over the original. Great job! Grabriggs (talk) 00:49, 3 December 2013 (UTC)

Comments from donbinincom

Thanks for the feedback Graham. Sarah, I have to admit I'm also a bit fuzzy on to what extent karyogamy is limited to fungi. All the references I've been able to find seem to focus on that form of life. How is it different from the merger of sperm and egg nuclei in mammalian fertilization? I wonder if we should make the lead a bit more general and then dive into fungi as Graham suggests. I'll also look for references for other biological groups. Don Brown (talk) 06:31, 3 November 2013 (UTC)

OK, this upcoming week I'll try to expand the section on fungi and find some sources for the role in somatic cells as well. Sarah Facci (talk) 02:02, 4 November 2013 (UTC)

Don, you may want to look into mitochondrial inheritance in fungi vs mammals to add to the last section. Annual Review of Genetics has an article called Sex in Fungi that addresses this. Sarah Facci (talk) 20:26, 23 November 2013 (UTC)

You bet. I plan to devote as much time to this tomorrow as I can. I'll look into that specific direction. Don Brown (talk) 04:16, 26 November 2013 (UTC)

Comments from Keilana

Hi guys, here are my comments on what you've done so far. Feel free to ask me if you have any questions!

• You have done a great job linking relevant terms, but it will help the lay reader if you gloss those terms.
• Usually you don't have citations in the introduction, rather, it should summarize the content that uses those citations later in the article.
• The last sentence of the first section needs a citation.
• The sources you are using are good so far. Good job.
• This needs some serious expansion. For example, you could explain the life cycle of ascomycetes in more detail and then show how karyogamy plays its role.
• One of the names in Gibeaux et al. is mangled into weird symbols - try using the special characters menu?

All the best, Keilana|^{Parlez ici} 20:37, 3 November 2013 (UTC)

Thanks for the tips, I noticed the weird characters but wasn't sure how to address fixing it. I see what you mean now. Also agree that it needs much more expansion, it is a quite in-depth topic! ! Sarah Facci (talk) 02:01, 4 November 2013 (UTC)

Comments from Sridenour

Firstly, this is a great start. And I have to agree with Keilana that the last sentence needs a citation. I also think that it may fit better under the Role section you have after the lead. Additionally, you may be adding this later, but don't forget a table of contents. The subject is a difficult one and I was wondering if you have thought of linking the vegetative cycle to the wikipedia page for yeast so the reader can quickly become familiar with some of the more difficult concepts? So far the coverage and links seem good and this looks like a great start. I had the same issue with the weird characters when citing a book as well. Also, don't forget to add some illustrations to aid in helping the reader in vision some of the processes described above.Sridenour (talk) 23:42, 4 November 2013 (UTC)

The table of contents is already there? Isn't it added automatically? Thanks for the tips about linking. I feel like I definitely didn't have enough time to expand enough last time and need to do that this week!Sarah Facci (talk) 20:07, 10 November 2013 (UTC)

Hey sorry bout the table of contents, I realized it was hidden when I was viewing it.Sridenour (talk) 19:35, 13 November 2013 (UTC)

Wanted to let you guys know that the page has really improved since my first review. Good job. Sridenour (talk) 16:12, 12 December 2013 (UTC)

Comments from KevinBrownJHU

So far this is a good addition. The lead touches on summing up the article so far, but will need to be expanded along with the article as you go. The article should be linked to appropriate categories to help improve the categorization of the site. Consider linking some of the latin/technical terms to the appropriate wiki pages when they first appear (Chlamydomonas or Saccharomyces cerevisiae. The article can probably be expanded with the already cited sources (7 references for 4 paragraphs seems pretty dense). Recheck the one wiki link that goes no where. That information might be on another page already and could be linked there instead of no where. I agree with the others. Try to expand the article a bit with pictures along with the text.

KevinBrownJHU (talk) 02:48, 6 November 2013 (UTC)

Thanks Kevin. We're trying to figure out the best way to ease into the subject before diving into the details. We'll work on adding appropriate links and fixing any broken ones. Don Brown (talk) 00:29, 12 November 2013 (UTC)

I've already addressed a couple of these things as well, along with some organizational updates and rewording. I hear what you're saying about the number of sources, but this is turning out to be a difficult subject to source material on. Often we are finding sources that only partly apply to karyogamy so are brief with their information on it.Sarah Facci (talk) 01:13, 12 November 2013 (UTC)

Comments from Klortho

You are making some definite progress on this article, but I think there's still considerable room for improvement. Here are some comments/suggestions.

• Good lead, but, I am very confused about something that I think should be made clear in the lead. What types of organisms does karyogamy apply to? In the next section ("Role of ..."), you discuss haploid organisms as a means to "demonstrate" the role of karyogamy, but I'm left wondering if it applies to diploid organisms, or not. The rest of the article compounds this problem. Please be very explicit and clear, in the lead, about what the scope of this process is.
• Would it be possible to get a better figure, one that is more specific to karyogamy? This one only has karyogamy as "#4", and that is just a very small part of the figure -- so it's not really effective.
• "Role of karyogamy in sexual reproduction".
  • This section is pretty good, but I found it to be confusing because you are jumping back and forth between the algae and the yeast. There is a good bit of pronoun confusion, I think. I wasn't sure, for many statements, which it applied to. Would it be possible to rewrite it a bit to only talk about one at a time? I.e., describe algae, and then, in the next paragraph, describe yeast, explicitly comparing and contrasting it to algae?
• "Pronuclear migration"
  • Could use more wikilinks
  • Would be nice if it were broken into two or three paragraphs
• "Cellular mechanisms" / "Experimental support" - I'm not sure why you have this subsection. It doesn't seem "parallel" to the other subsections in "Cellular mechanisms", which each list one of the mechanisms. It seems to me that info about experimental support, if it needs to be included at all, should be inline with the content that it is supporting.
• In general, it would be great if this article had some more figures. One place to start to see if you could find some is this search for open access articles in PMC: http://www.ncbi.nlm.nih.gov/pmc/?term=karyogamy+AND+open+access%5Bfilter%5D.
• "Role of karyogamy in somatic diploids"
  • Is this an abnormal, or pathological condition, or not?
  • This whole section is confusing to me. You mention the formation of somatic diploids, but it's not clear what "the role of karyogamy" is supposed to be. In the earlier section, "Role of karyogamy in sexual reproduction", you mention that haploid cells fuse, which I presume means that they form diploid cells, but you never mention whether or how they separate out to become haploid again. So this "Role of karyogamy in somatic diploids" is lacking any context by which I can tell that what you are describing is different from the normal state of affairs.
• "Similarities to mammalian fertilization"
  • Maybe this should be titled, "Comparison to ...", and you could list similarities and differences?
• This article is a bit short - I think you should have more content by now.

Klortho (talk) 05:54, 20 November 2013 (UTC)

Thanks for the feedback, you always have something very concrete to add. I agree that I thought we'd have more content as well, but it seems to be pretty difficult to find information on the topic, especially when trying to limit ourselves to freely available articles and books. I'll have to delve into some of the less free sources this week. 74.47.149.111 (talk) 06:49, 23 November 2013 (UTC)

Whoops, wasn't logged in. Sarah Facci (talk) 07:05, 23 November 2013 (UTC)

Comments from AjoneWiki

You can really tell that your article is taking shape. These are my comments, please let me know if you have any questions:

• I read through the lead section 3 times, as I got stuck in the terminology and technical information. Is there a way to make to make it a little bit less dense, but still as informative?
• Most importantly, it would be nice to have more pictures and illustration. This would really help to allow the reader to visualize topics like the "sliding cross-bridge" and the "plus end model".
• Also, it might be beneficial to add additional wiki links to explain some topics, such as "mating type".
• I don't understand why the section "Experimental support" is under "Cellular mechanisms".
• In you last section it doesn't become clear what's different between "fertilization" and "karyogamy".
• A few of your sections still need further expansions in terms of context.

AjoneWiki (talk) 18:54, 21 November 2013 (UTC)

Yes, we are going to try to come up with a less technical lead and ease readers into the subject. Your comments were very helpful. Don Brown (talk) 04:13, 26 November 2013 (UTC)

I like the new lead section!AjoneWiki (talk) 23:36, 14 December 2013 (UTC)

Comments from Birdy0124

1. Lead section
a) After the two opening sentences, you focus on the role of karyogamy in fungi. Since this article is about the general biology of karyogamy, it may be better to place the specifics on fungi in a later section. Instead, you may want to include one or two sentences to elaborate on your opening sentence. For example, can you explain in general terms what “pronuclei” mean, what “fusion of pronuclei” means? Also “pronuclei of two cells”, do you want to say “pronuclei of two gametes” or “pronuclei of two sex cells” to be more specific?
b) It may define the scope better if you open the section by “In reproductive biology” or “In sexual reproductive biology” instead of “In cellular biology.”
2. Role of karyogamy in sexual reproduction.
a) Although the section title implies that you will be describing the roles of karyogamy in sexual reproduction biology, the first sentence suggests that you focus on the role of karyogamy in cell cycle instead. That seems to be much narrower topic than what I (a reader) would have expected from reading the title.
b) For the next few sentences, you actually use two organisms to explain what happens before and during karyogamy, and the outcome of karyogamy. I like the specific examples you give. But karyogamy seems to be a preparation for the actually meiosis cell cycle. Looking back at the first sentence of the paragraph, how about changing “in cell cycle” to “in sexual reproduction”?
c) Is it possible to start the paragraph with a general description of the biological role of karyogamy and then illustrate with specific examples? Also this may be a good place to move the fungi related material in the lead section to. I imagine that most general readers would be interested in learning how karyogamy works in human or vertebrate. May be also include an example from the high eukaryotic species?
3. Cellular mechanisms
a) Pronuclear migration. 1) “The microtubule plus ends attach to the opposite pronucleus” where is the attachment point on the pronucleus? 2) “Two models have been proposed” Models for what? 3) “the sliding cross-bridge, and the plus end model” probably should be “the sliding cross-bridge model and the plus end model”. 4) Can you find a figure to illustrate the process? As it is now, it is a bit difficult to follow.
b) Fusing of pronuclei. 1) To be consistent, may be use “Fusion of the pronuclei” or “Pronuclear fusion”. 2) An important step to explain is what happens to the two nuclear envelopes. Do they disassemble like what happens at the beginning of metaphase or do they fuse like two intact vesicles?
c) Experimental support. I am not sure if this subsection adds much to the article. You probably can merge the paragraph with “Pronuclear migration.”
4. Role of karyogamy in somatic diploids.
This section appears to be under construction. Some introduction is needed to help understand the material and how it adds to the article.
5. Similarities to mammalian fertilization
This is where I get confused. From what I have read, the fusion of pronuclei during fertilization is called karyogamy in all organisms. People use this (and other evidence) to argue that the basic principles of sexual reproduction are conserved. Karyogamy is one step during fertilization. If the term karyogamy is restricted to yeast, fungi and algae, what do biologists call pronuclear fusion in mammalian fertilization?
6. Figure.
It is not clear what organism is depicted here. Can you describe the figure and explain the individual steps? Again, I suggest include a figure to explain “Pronuclear migration.”
7. References.
I like reference 4, 5 and 6, which are very specific. Like many premiere scientific journals (Nature, etc), wiki guidelines recommend using specific references. References 2, 3 and 7 seem to be too general (i.e. if a reader wants to check the source, he/she has to look through a big textbook to find the necessary passage cited).
Birdy0124 (talk) 18:00, 22 November 2013 (UTC)

Thanks for the perspective. I realized we were confused when we started the article and it led to the text being confusing also. Hopefully it is clearer now that the term karyogamy applies to haploid organisms (and therefore not all eukaryotes). I'm trying to balance the sexual reproduction section in terms of which organisms are used as examples. Also the section about sexual reproduction is supposed to be in contrast to the somatic section, as karyogamy can be used in sex cells or in somatic cells. Hopefully this will become clearer as I add more information this week. I am open to any suggestions! Sarah Facci (talk) 20:31, 23 November 2013 (UTC)

Comments from LutyeusMaximus (Seth)

Great article. You have packed alot of information into this article.

• In the first opening paragraph I think you explain it pretty simply. I think the lay reader could get it and you have wikilinked anything they would have questions about
• That first image is clutch, I think it really helps display what you are explaining
• The first thing I noted overall for the article is that there is a lot of information and not many in text citations. For instance the Importance in certain organisms section has no in-text citations
• In the overview section the second to last sentence is missing a step, I provided a variation to show what I mean; The advantage of sexual reproduction is the same as in any organism: more genetic variability provides the an increased opportunity for adaption, which could lead to increased fitness
• I like the use of Chlamydomonas and Saccharomyces cerevisiae as examples
• Under Pronuclear migration you talk a lot about microtubules and the + and - ends, for the lay reader I might just add a little more backgroud about the + and - ends of microtubules, i would keep it brief but I think its needed
• As noted in the article I agree that the Role of karyogamy in somatic diploids section needs expansion

Hope my comments help, let me know if you have any questions LutyeusMaximus (talk) 02:51, 4 December 2013 (UTC)

Hi Seth, Don just made some changes a few days ago separating the lead section into the overview and the "certain organisms" section. We were discussing the merits and drawbacks of possibly recondensing (and definitely renaming) the sections a bit. Any opinions? Also, I'll definitely add some more about the microtubules, thanks. 209.252.247.242 (talk) 03:08, 4 December 2013 (UTC) (whoops forgot to log in again Sarah Facci (talk) 03:09, 4 December 2013 (UTC))

Hi Sarah, so on my initial read I didn't really pick up on any problems with those sections being they way they are in their current state. Looking back at it now, I definitely like the way the first intro paragraph is and I wouldn't change that. If anything you could maybe combine the Overview and Importance in certain organisms sections LutyeusMaximus (talk) 15:05, 4 December 2013 (UTC)

Ok, so I was "bold" and reorganized the first few sections. The redundant material was thorough, but it was driving me a little crazy. I think we will have to revisit and make sure all citations are present, since the cut and pasting was extensive. I'd love some feedback as to whether everything is still clear. Don, I left your "certain organisms" section and expanded it a bit. I hope that was a good compromise for everyone! Sarah Facci (talk) 07:11, 5 December 2013 (UTC)

Comments from Rokasj1

It’s a very nice progression of an article and I believe that previous reviewers covered most of the concerns. I have only few suggestions to make the article more clear:

1)Figure 1 maybe should be named as “Karyogamy in the cell fussion process” rather than Karyogamy overview. 2)Section “importance in haploid organisms” could be called “karyogamy importance in haploid organisms”. 3)Pheromone is misspelled in section “role of karyogamy in sexual reproduction” 4)Sentence “The advantage of sexual reproduction is the same as in any organism: more genetic variability results, providing the opportunity for adaption” is repeated verbatim twice.

Pronuclear Fusion section could use a little bit more detail, as this is the most important section of the article,

rokas (talk) 01:49, 8 December 2013 (UTC)

Thanks very much for your comments- I can't believe I misspelled that! And apparently had some copy-paste errors as well. I had next week planned to finish expanding that last section so hopefully you will come back and let us know your thoughts on that as well! Sarah Facci (talk) 01:55, 8 December 2013 (UTC)

More comments from Keilana

Hi guys! Great job so far. I wanted to give you some more comments before the final push to the end of the semester. As always, let me know if you have any questions!

Lead and images

• The Free Dictionary citation has a broken link - check your formatting.
• Not sure what "Number 4" is referring to in the second image caption.
• Ditto with "fission yeast".
• You don't need a parenthetical citation to Rose 1996 in the caption, if what you're talking about is not discussed elsewhere in the article then you can cite it with a regular reference.
• Glossing "shmoo tip" would be very helpful.
• In general, good choice of images and good job explaining each one.

Importance in haploid organisms

• This section needs at least one citation per paragraph.
• You linked most of the important terms, however, I would also add links to cell cycle, genetic recombination, gamete, and fungus; and change the link to somatic to link to somatic cell.
• You link somatic twice in the section, once is enough.

Role of karyogamy in sexual reproduction

• The first paragraph needs a citation.
• It would be helpful if you glossed the term "gametangia".
• The Cornell fungi source is okay, but I would prefer you augment it with a journal source. The author of that piece links several that would be good options.
• You use the "X is a process known as Y" structure a lot and it gets repetitive. Consider rewriting a few of those sentences.
• The last part of the last paragraph needs at least one citation.

Cellular mechanisms

• It would be nice to have a brief overview before diving into the subsections.
• I don't think "plus end" and "minus end" should be italicized.
• A little bit more explanation on how the microtubule mutants cause karyogamy but not meiosis to fail would be good. The way it stands the reader has to infer a LOT and it assumes a little too much knowledge about the details of sporogenesis/meiosis on the part of the reader.
• The last sentence needs a citation.

Role of karyogamy in somatic diploids

• I agree with the tag - this section needs expansion. I recommend more explanation of the karyogamy repressor gene and how this generally works in fungi.

All the best with the last part of the semester! Keilana|^{Parlez ici} 07:08, 10 December 2013 (UTC)

Thanks a lot! We just did a couple major rewrites of the first couple sections and I think we lost some of our citations and links in the process. We'll definitely revisit all your suggestions! Sarah Facci (talk) 08:06, 10 December 2013 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Karyogamy/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Rated "high" as important for fungal cells and life cycle, as well as fertilization in general. - tameeria 04:29, 19 February 2007 (UTC)

Last edited at 04:29, 19 February 2007 (UTC). Substituted at 20:56, 29 April 2016 (UTC)