Talk:Gene expression

This  level-4 vital article is rated B-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Molecular Biology: Genetics / MCB This article is within the scope of WikiProject Molecular Biology, a collaborative effort to improve the coverage of molecular biology on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Molecular BiologyWikipedia:WikiProject Molecular BiologyTemplate:WikiProject Molecular BiologyMolecular Biology ??? This article has not yet received a rating on the project's importance scale. This article is supported by the Genetics task force (assessed as Top-importance). This article is supported by the Molecular and Cell Biology task force (assessed as Top-importance).

Gene expression received a peer review by Wikipedia editors, which is now archived. It may contain ideas you can use to improve this article.

A summary of this article appears in gene.

This article was the MCB Collaboration of the Month for the month of April 2009-February 2010. For more details, see the MCB Collaboration of the Month history.

Southgatea (talk) 21:28, 25 February 2020 (UTC) edits to the article to make it more general. more as an entry page to more generalized articles. in that spirit added link to other pages. Also introduce the connections to the central dogma.Reply

Need slow throughput techniques e.g. northern blot --Zven 12:12, 17 September 2006 (UTC)Reply

I just updated this entire section, adding, for example, the northern blot, and a little more information on DNA microarrays. I also cleaned up the language to make it hopefully more accurate. I also updated the protein-level measurement part, since the original author was apparently unaware that Western blots are still the standard method of choice for reporting protein levels. Let me know what you think. -- Josh 03:36, 7 June 2007 (UTC)Reply

Consider the totality of all gene expressions within a chromosome. Are all genes on the same side of the DNA strand? In other words if you split the double helix are all the genes on one strand or are they staggered between the two strands?

If I remember correctly, which I think I do, each strand is just the mirror image of the other one. Codons on one strand match up with Anti-codons on the other.--Urthogie 21:37, 22 April 2007 (UTC)Reply

Genes are dispersed among both strands in a single chromosome. With 100% confidence. -- Josh 03:39, 15 May 2007 (UTC)Reply

Backing that up, open reading frames can occur on either strand in either direction Silasmellor (talk) 14:22, 10 May 2009 (UTC)Reply

moved terms to Glossary of Scientific Terms related to Gene Expression. Removed empty section.

Why does housekeeping genes redirect to this article? ώЇЌĩ Ѕαи Яоzε ^†αLҝ 21:50, 11 June 2007 (UTC)Reply

• I'm assuming because there is no 'housekeeping genes' article yet, that you need to underestand gene expression at least a bit to understand housekeeping genes, and that this article is the most informative one that the person making the redirect could find at the time. Jethero^Talk 00:25, 9 July 2007 (UTC)Reply
  • Now redirects to Glossary of gene expression terms#H --Jethero^Talk 00:30, 23 June 2008 (UTC)Reply

Was:

• '''Gene expression''', or simply '''expression''', is the process by which a [[gene]]'s [[DNA sequence]] is converted into functional [[proteins]].

But:

• DNA is not 'converted', but transcribed, leaving intact DNA behind
• the term 'DNA sequence' does not capture epigenomic 'information', which may indeed be part of the inheritable trait, or genetic information, and have an effect on the amount or structure of the 'expressed' gene or trait.
• not all 'gene expression', and perhaps not even most, results in protein production. Protein is not the only trait, or 'expression' of genetic information
• Sentence from gene article was more comprehensive, but not quite what we need here. "The process of producing a biologically functional molecule of either RNA or protein is called gene expression, and the resulting molecule itself is called a gene product."
• however, this still needs to be simple, so please continue to refine.

So is now:

• '''Gene expression''', or simply '''expression''', is the process by which the inheritable information which comprises a [[gene]], such as the [[DNA sequence]], is made manifest as a physical and biologically functional [[gene product]], such as [[protein]] or [[RNA]].

Jethero^Talk 00:49, 9 July 2007 (UTC)Reply

I removed the initial lines "The expression of many genes is regulated after transcription (i.e., by microRNAs or ubiquitin ligases), so an increase in mRNA concentration need not always increase expression. In fact, mRNA concentration has been shown to be a poor predictor of resultant protein abundance.[1][2]" because IMHO it serves as a pretty bad start for what essentially should just be a walk-through of the different methods that exists to quantify mRNA (ie. the de facto definition of gene expression in the litterature). Even if we do want to talk proteins, and I agree that this is relevant, it should come in another section. --LasseFolkersen (talk) 12:50, 31 March 2009 (UTC)Reply

• It might be useful here to talk about microarray technology in a bit more depth than just a mention. Thoughts? Contributions/160.94.10.132 (talk) 14:25, 15 June 2009 (UTC)Reply

• With regards to the sentence "The stability of the final gene product, whether it is RNA or protein, also contributes to the expression level of the gene - an unstable product results in a low expression level." Should an unstable protein not require a high gene expression level? Can anyone confirm this? Lady of the dead (talk) 21:00, 7 September 2009 (UTC)Reply

This article is the MCB Wikiprojects Collaboration of the Month. What does it need? It appears to me that each of the sections should have a "main article: bla" link in it, for starters. Then we need to decide how much detail goes into those sections, as each step (i.e. Transcription, Translation, etc.) has its own article already. Should we be trying to improve the overall understanding of the whole process of expression here? It's not entirely clear to me what the goal of the article is. Agathman (talk) 00:11, 28 May 2009 (UTC)Reply

The two core questions in any article are "what is it" and "why is it important". The article could do with a better lead that would give a broad and simple overview, less emphasis on techniques (which are of limited interest to most of our audience) and a much expanded section on the various levels of regulation. Tim Vickers (talk) 02:57, 28 May 2009 (UTC)Reply

This article currently has a significant eukaryoitic bias; please try to avoid this! I will make some edits to clarify the differences between prokaryotic and eukaryotic gene expression, particularly with respect to co-translation in prok's, RNA processing, nuclear export, folding location and secretion via exocytic pathways. - Zephyris _Talk 10:33, 29 July 2009 (UTC)Reply

The protein expression article seems abandoned. Should it be deleted and redirected to gene expression? Pdcook (talk) 19:38, 11 September 2009 (UTC)Reply

Oppose. Protein expression is related to gene expression but nevertheless is a distinct subject. A quick search of PubMed and Google Books reveals an enormous amount of material that has been published on this subject (a few citations to review articles and monographs has now been added to the article). Therefore I believe protein expression deserves its own article. Boghog (talk) 10:34, 12 September 2009 (UTC)Reply

I do see your point, but most of the information contained within protein expression is already present within the gene expression article. We could perhaps have a section within the gene expression article entitled protein expression. I have also noticed that many times when we say protein expression we actually do mean gene expression. Pdcook (talk) 15:07, 14 September 2009 (UTC)Reply

More often mRNA expression is meant. Redirecting from a non-synonym will only cause confusion and/or force awkward layout here; this article is prominently linked from protein expression anyway. Plus this article already has problems with clearly separating protein and RNA. Narayanese (talk) 15:44, 14 September 2009 (UTC)Reply

I wonder if the definitions of these terms vary depending on field of study. A geneticist versus a protein biochemist might define them differently, and certainly the distinction is nebulous at best. I guess from my perspective, protein expression can only be a subset of gene expression, unless you're including artificial peptide synthesis. I'm curious how others differentiate these two terms.Pdcook (talk) 22:43, 14 September 2009 (UTC)Reply

I have a feeling it's the same across the fields, i e that its a subset. Narayanese (talk) 22:00, 16 September 2009 (UTC)Reply

In one of my second year introductory lectures, we were asked at what stage we considered that a gene was expressed. The biochemists and geneticists said it was as soon as mRNA is transcribed, the microbiologists said it was once protein was produced, and the biologists were mostly split between those two with a few that saw it as being at the point of the gene's phenotypic manifestation. I'm generalising of course, but that was the general trend. So in that crowd at least, there was a divide (sorry about the mini-essay to make the point).

I don't think there should be a page dedicated solely to the protein expression side of gene expression; we'd just be repeating ourselves. It seems to me that the citations in the protein expression article focus on the biotechnology side of protein production? Yes, this is a very important line of research, but there's a distinction to be made. Is there not a more suitably titled page for the biotech. aspect? Or could we move some of it to more suitable pages? For instance one of those cited articles (>>) at least seemed to me like it would be more at home in the expression vector article. Ribrob (talk) 16:01, 18 September 2009 (UTC)Reply

As you might imagine, I agree with Ribrob. It doesn't seem like we're saying anything new in the protein expression article. Even the biotechnological aspect is covered to a greater extent in the gene expression article. Pdcook (talk) 17:20, 18 September 2009 (UTC)Reply

It would be nice if we could make a decision on this soon. Pdcook (talk) 03:22, 27 September 2009 (UTC)Reply

In think Ribrob's comments are very helpful. In the field of molecular biology, protein expression is certainly a subset of gene expression while in the fields of biotechnology and proteomics it is distinct. Furthermore in the field of expression profiling, (gene expression) ≠ (protein expression) since the mRNA levels do not necessarily correlate to the amount of expressed protein. So I propose that the protein expression article be renamed to something like "protein expression (biotechnology)" and the material in the gene expression article relating to biotechnology be moved to the "protein expression (biotechnology)" article. Boghog (talk) 06:33, 27 September 2009 (UTC)Reply

I think that is a great idea, Boghog. Pdcook (talk) 19:29, 30 September 2009 (UTC)Reply

Keep per WP:NOEFFORT, WP:PNJCS etc. --Kkmurray (talk) 17:15, 19 October 2009 (UTC)Reply

Concur with BogHog . Additional bird killed with that stone: The gene expression article is nice and short, while clearly directs to the various subtopics. only longer section there is gene expression systems which would fit perfectly in protein expression (biotechnology). I think that is decided! --Squidonius (talk) 10:26, 20 October 2009 (UTC)Reply

 Done Thanks for everyones support. Per the discussion above, I have moved most of the material in the Gene_expression#Expression_system section to the newly renamed protein expression (biotechnology) article. Cheers. Boghog (talk) 06:33, 28 October 2009 (UTC)Reply

Thanks. I think it's a big improvement. Pdcook (talk) 23:08, 9 November 2009 (UTC)Reply

The previous version of this text explained correctly, that the produced RNA strand is complimentary to the used template DNA strand. DNA "TAC" to RNA "AUG" (encoding for methionine and also serving as start codon for translation) was given as an example. However, the template DNA strand is itself read in "reverse" 3' → 5' direction to create the new strand in 5' → 3' "sense" direction. The newly generated 5' → 3' RNA is therefore identical to the 5' → 3' coding strand of the DNA (complimentary strand of a complimentary strand), with the difference that T is replaced by U in RNA, of course. This new version is in concordance with the more detailed Transcription (genetics) article and, I believe, less confusing to the first time reader. --Firefly's luciferase (talk) 03:01, 26 February 2010 (UTC)Reply

The words inducible gene redirect here and yet there's absolutely no trace of the word "inducible" in this article. Someone fix this please or remove the redirect and create a separate article for what an inducible gene is. 98.176.12.43 (talk) 19:34, 9 October 2010 (UTC)Reply

The term inducible gene was defined in a previous version of this article but lost in subsequent edits. I have reintroduced these definitions. In addition, I have changed the redirect of inducible gene to the more specific Gene_expression#Regulation_of_gene_expression. Boghog (talk) 20:52, 9 October 2010 (UTC)Reply

I also just noticed that a definition of an inducible gene was included in the Glossary_of_gene_expression_terms#I. Boghog (talk) 07:25, 10 October 2010 (UTC)Reply

Regulation of gene expression#Methods has a more extensive section on tools, albeit it has a focus on whether the abundance measured is relative or absolute (e.i. protein foo @ condition B is n times higher than @ condition A or foo is n pM ), as the article is about change in expression levels. Maybe a copy-paste possibility? --Squidonius (talk) 03:21, 10 October 2010 (UTC)Reply

Overexpression redirects to this article. What does it mean? --Abdull (talk) 12:29, 2 June 2012 (UTC)Reply

Overexpression = gene expression above the normal amount. This can be done in the laboratory for example by gene knockin (inserting extra copies of the gene into a cell). Overexpression is also a possible mechanism by which pathogens or cancer cells can become resistant to drugs. Boghog (talk) 12:46, 2 June 2012 (UTC)Reply

Both the articles refer to the same thing. I see no dissimilarities. The ultimate goal of gene expression is protein synthesis. These two articles are like seeing a snake from its mouth and from the tail. So I propose to merge the two articles. This message will also be posted on Gene expression article. --G.Kiruthikan (talk) 13:58, 1 March 2014 (UTC)Reply

Overexpress and Overexpression redirect to this article but are not defined. Should the article cover the term or should redirects be removed? pgr94 (talk) 10:41, 12 May 2014 (UTC)Reply

The comment(s) below were originally left at Talk:Gene expression/CommentsTalk:Gene expression/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.

high school/SAT biology topic; important overview of central MCB topic (most molecular biology research revolves around gene expression in one way or another); changed rating from high to top - tameeria 15:23, 18 February 2007 (UTC)Reply

Last edited at 15:23, 18 February 2007 (UTC). Substituted at 15:53, 29 April 2016 (UTC)

Long sections on "Transcriptional regulation in cancer" are being added to different articles on genetics. Whether these are WP:UNDUE is a matter of opinion, but that they are similar is not in doubt. It would make more sense to create a single article on that topic, and to link to it with a brief summary in each of the other articles. Chiswick Chap (talk) 07:22, 30 October 2016 (UTC)Reply

Since the section was duplicated in at least 3 articles including this one, I've boldly factored it out leaving a main link and a very brief summary. I'm sure that can be improved upon, and it needs a general reference to a suitable review paper (unfortunately there wasn't one in the text). Chiswick Chap (talk) 08:00, 30 October 2016 (UTC)Reply

Please refer to the following line from the section 3: Measurement

".....ability to quantify the level at which a....."

Can we write "degree" instead of "level"? It sounds more expressive to me. I am not an expert, just a suggestion

''Prabhakar Sarma Neog'' (talk) 13:42, 1 August 2017 (UTC)Reply

Not sure if this is the way to ask questions. Apologies otherwise.

   In the section on mechanism there is the following statement:

"The ribosome helps transfer RNA to bind to messenger RNA and takes the amino acid from each transfer RNA and makes a structure-less protein out of it.[9][10] Each mRNA molecule is translated into many protein molecules, on average ~2800 in mammals."

My question: Are these 2800 DIFFERENT proteins of 2800 COPIES of a protein molecule? can someone clarify.
   Thanks  — Preceding unsigned comment added by 24.251.100.217 (talk) 00:47, 6 January 2019 (UTC)Reply 

An editor has identified a potential problem with the redirect Over expression and has thus listed it for discussion. This discussion will occur at Wikipedia:Redirects for discussion/Log/2022 February 5#Over expression until a consensus is reached, and readers of this page are welcome to contribute to the discussion. Steel1943 (talk) 20:58, 5 February 2022 (UTC)Reply

Overexpression and Over-expression are also listed. Jay (talk) 07:27, 13 February 2022 (UTC)Reply

I propose that we remove this article and replace it with a stub containing links to gene, transcription, regulation of gene expression, translation, etc.

This is another example of redundant information that conflicts with the main articles on the subject. There's no point in having so many articles that cover the same topics - it encourages people to make edits that don't agree with information found elsewhere. Genome42 (talk) 18:32, 2 February 2024 (UTC)Reply

I have not changed the opinion that I expressed one year ago. I think this article should be entirely deleted and we should link to better articles on similar topics. There are far too many Wikipedia articles on molecular biology topics and many of them are becoming bloated with too much picayune detail and anthropomorphic bias.

Furthermore, the information in those myriad of articles often conflicts.

The recent addition of a "protein degradation" section to this article is a good illustration of the problem. Is this really an example of gene expression?

The vast majority of proteins are present at steady-state levels in most resting cells and they increase when a cell is about to divide. The turnover rate is mostly determined by the structure and location of individual proteins. Some proteins are integral parts of large complex structures, such as ribosomes, photosystems, muscle, or complex II in mitochondria. These proteins have long half-lives. Some proteins, such as most metabolic enzymes, have variable half-lives but they tend to be fairly lengthy as you might expect.

A much smaller number of proteins turn over rapidly because they are only needed for a short period of time and their continued presence in the cell might be detrimental. Transcription factors in the developing embryos of multicellular animals are a good example. These proteins have evolved a structure that makes them susceptible to rapid degradation.

The recently inserted section begins with, "Protein degradation is a major regulatory mechanism of gene expression and contributes substantially for shaping proteomes, especially of tissues and cells that do not grow very fast." I do not believe that most protein degradation is regulated (as opposed to intrinsic) in bacteria and yeast and I do not believe that it can in any way count as a "major" mechanism of gene expression.

The next sentence is, "Protein degradation is a highly regulated processes." The correct statement would be "Protein degradation is mostly an intrinsic property of the structure and location of a particular protein but there are known examples of the regulation of degradation proteases, especially in large multicellular species with many different tissues and cell types." Genome42 (talk) 15:53, 22 February 2025 (UTC)Reply

Genome42 Sounds to me like a good case for improving the article. Per Wikipedia's guideline on broad concept articles, we shouldn't be replacing articles with disambiguation or set index pages just because they're difficult to write or maintain. Now, technically you could take this article to WP:AfD to directly seek deletion, but it would absolutely not pass consensus owing to sufficient coverage (see https://en.wikipedia.org/wiki/Wikipedia:Articles_for_deletion/NUS1, for example). Regarding the section on protein degradation, a lot of details do seem to be sourced to scientific articles that may not reflect general scientific consensus WP:PRIMARY. I would be more than happy to review the material together, and perhaps locate better sources such as a literature review or up-to-date textbook. — 🪫Volatile ^{📲T | ⌨️C} 03:25, 22 July 2025 (UTC)Reply

The last thing we want to do is improve this article. The main problem is not that it needs fixing, it's that it overlaps with lots of other articles on Wikipedia. Note that most of the subtopics begin with a link to another "Main article." What's the point of describing transcription, for example, in this article when we already have a complete article on Transcription?

The risk is twofold. First, the two articles might conflict. Second, anyone who wants to update material on transcription now has to edit (at least) two articles to make sure they agree. This discourages responsible editors from trying to clean up the morass of articles on molecular biology.

With respect to protein degradation, my point was that this topic is not usually thought of as an aspect of gene expression so it doesn't belong here. Do you have any references or citations that link protein degradation to gene expression? I write biochemistry textbooks and I've never considered protein turnover to be a important part of gene expression.

Note that Protein degradation on Wikipedia redirects to Proteolysis and that article thoroughly covers all the important features of protein turnover. If you really think it's necessary to include this topic here then why not just include a link to the proteolysis article rather than try to create a whole new section that covers the same topic?

There are also articles on Endoplasmic-reticulum-associated protein degradation, Proteasome, Protein, Protein catabolism, and the N-end rule that cover the same material. Do you see the problem? Genome42 (talk) 17:36, 22 July 2025 (UTC)Reply

Regarding the protein section, I'm in agreement here. It appears the section is only supported by a handful of articles in the literature, as opposed to reviews or textbooks that mention the relevance of protein degradation in gene expression. Therefore, that section should most likely be removed.

What I disagree with is stubbifying this article, turning it into a list of topics. Per WP:DETAIL, a Wikipedia editing guideline that should be generally followed, Wikipedia caters to a variety of readers: those who want a quick summary (lead section), those who want a moderate amount of detail (standard multi-paragraph article), and those looking to dive in-depth into the subject matter (sub-articles).

By your argument, the lead summary sections of articles contains redundant information that overlaps with coverage in the article, leading to more work for editors to maintain (since they have to change both body and the lead to update the article). Therefore, we should remove the lead for every article, instead letting readers rely on the Table of Contents to locate their desired information.

Do you see how that's not helpful for readers who simply want a quick overview of the subject? — 🪫Volatile ^{📲T | ⌨️C} 03:35, 27 July 2025 (UTC)Reply

I deleted the section on protein degradation.

This is an article on gene expression (i.e. the expression of a gene to produce a functional product). The main topics are transcription and translation but it's probably a good idea to include RNA processing.

I see your point about having an article that presents a quick overview of the main topics (transcription, RNA processing, translation) as long as they don't go into too much detail. Let's leave them.

Some of the other topics seem to be unnecessary such as: RNA export, Folding, Translocation, and Protein transport. This is too much detail for someone who just wants a quick overview.

But the main problem is the lengthy section on Regulation of gene expression. This is a complex subject and it's fully covered in other articles. Some of the material is controversial and there's a big risk that it conflicts with what's written elsewhere. I suggest that the lead is sufficient in this case.

There are also large sections on "Measurement," "Expression system," "Gene networks," and "Techniques and tools." These don't seem to be suitable for an article intended for an audience who wants a quick summary of the main features of gene expression.

I think you may have misunderstood my criticism. I don't object to information in the lead that is explained more fully in the main body of the article. What I object to is information in one article that conflicts with information in another article. These are complex and controversial topics so in my opinion we should try and limit the number of places where conflicts can arise Genome42 (talk) 16:41, 27 July 2025 (UTC)Reply

Agreed, if the information presented here conflicts with a sub-article, we should definitely reconcile it.

I agree the RNA export, Protein transport, and Translocation sections could be removed entirely, their only significance is noting that RNA and proteins must be present in the correct location in order for genes to express. Protein folding should still be covered, since tertiary structure is significant in the function of the protein. Perhaps the subject could be given a similar treatment as Genetics#Gene expression.

Most of the material in regulation of gene expression should probably be moved back to the sub-article (which is a mess of its own kind with the duplication of information on Enhancers). Whatever conflicting information is present will most likely need to be adjusted through discussion.

The measurement section is probably the most tricky, since I don't see a relevant sub-article on "Measurements of gene expression". I'll leave that section for a future comment or discussion — 🪫Volatile ^{📲T | ⌨️C} 22:54, 27 July 2025 (UTC)Reply

I tried to simply the introduction. Boghog made some additional changes that require comment.

I wrote that gene expression is the process by which information in a gene is expressed as a functional gene product (protein or RNA). Boghog changed "information" to "instructions encoded" but using the word "encoded" seems to ignore the large number of expressed non-coding genes. I don't see the advantage.

Boghog also added "most commonly a protein but sometimes a functional RNA." Again, this seems unnecessary and seems to downplay the role of hundreds or thousands of non-coding genes.

Boghog then specifically describes the expression of protein-coding genes but not non-coding genes. I don't understand why that was a necessary addition.

Boghog then added a few sentences about the regulation of gene expression, which should, in my opinion, be treated as a separate subject. The claim is that "gene expression is tightly regulated" but that may or may not be strictly true in all cases. Indeed, it seems likely that a large number of housekeeping genes are constitutively expressed in both prokaryotes and eukaryotes. Surely this opinion is something that should be explained and discussed in the main body of the article on regulation of gene expression?

The last sentence refers to differentiation and physiology but those only apply to multicellular organisms so I don't see why it has to be emphasized in the introduction. Genome42 (talk) 19:59, 2 August 2025 (UTC)Reply