Talk:Telomere

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Peer reviewers: M bartolo. This article was the subject of a Wiki Education Foundation-supported course assignment, between 27 January 2020 and 8 May 2020. Further details are available on the course page. Student editor(s): Malaika1089 (article contribs). Peer reviewers: Random from the burgh.

Histone Modifications in Telomeres

I removed this section from the main wikipedia page because it is likely only of interest to specialists (maybe just the author shilling their own work?) and the article is already too sprawling and hard to read.

The telomeres of human cells have been found to have a unique histone modification pattern, with the most enriched modifications being H2BK5me1 and H3K3me3 and the least enriched modifications being H3K36me3 and H3K9me3 

Telomeres and cancer section

There is an awful lot of information on Telomerase in the cancer and Telomerase section. I believe this should be moved to the Telomerase page, however I do not have much expertise on the subject and so open up a request for someone else to edit this?

Also, I plan to work on the ALT section. I don't know about moving this out into a separate article for the time being; there is not much information and I feel it fits well into the Telomere article after the re-jig.--Rachemon (talk) 18:03, 10 August 2016 (UTC)

Hi, sorry, I don't know how to comment on the actual section I have a question about. I updated a link in the External Links section that was out of date. (The link had changed on the linked-to site, iBiology.) Someone first reverted the link to the bad, old link, then removed it entirely. Liz's talk on the iBiology is an excellent video of her explanation of her work. I do not understand the series of edits that were made. Can someone revert to my original edit, which corrected a bad link? Yowangdu (talk) 22:39, 2 July 2018 (UTC)

The topic of telomeres is still in the research stage, i.e., it's WP:PRIMARY, which is too undeveloped to include much about it as encyclopedic other than as preliminary research. For medical topics, such as lowering cancer risk, we use the sourcing guide, WP:MEDRS, and this tutorial may help. Please don't stretch the telomere content beyond what can be supported by MEDRS sources. The Lengthening section needs work. --Zefr (talk) 23:45, 2 July 2018 (UTC)

Olovnikov

The section and sources below were removed because a) they advance only a theory that is part of telomere discovery, but developed more completely with actual evidence by others, b) they source references, some in Russian, that were superseded by more recent and complete sources, and c) the Olovnikov discussion - which is promotional to his theory and off-topic to current knowledge about telomeres - can be stated more simply, and is given coverage at Hayflick limit. In this revision, I trimmed the discussion and added a review. --Zefr (talk) 23:08, 13 March 2018 (UTC)

soviet/russian biochemist Alexei Olovnikov was first to formulate and published the theory of marginotomy (in The Journal of Theoretical Biology, 1973), concluded in that chromosomes could not completely replicate their ends. Building on contemporary state of the art and accommodating Leonard Hayflick's experimental results of limited somatic cell division, Olovnikov suggested that DNA sequences are lost every time a cell/DNA replicates until the loss reaches a critical level (Olovnikov's clock), at which point cell division ends. Basing on the theory, he explained endless and non-aging division of bacterial cells by circular structure of their DNAs, and the same in stem and cancer cells by acting of unknown cap-recovering enzyme - discovered in 1984 telomerase. However, neither he nor his contemporaries (Watson, the end-replication problem, 1972) were not awarded the Nobel Prize for this discovery.

References

a) As for the theory, it's ability to explain the peculiarities of bacterial, spinal and cancer DNA, emphasized the correctness of the underlying assumptions and indicated the direction of further research. The mention of the essence of the theory is important for reflecting the development of the concept of telomeres and telomerase.

b) The underlined statement that the English-language publications of Olovnikov went unnoticed sounds strange, given the much smaller volume of scientific publications in 1970s, especially in cell biochemistry, and general accessibility of abstract journals. Apparently the author of the line was not very good at the question.

c) The discovery of telomeres by Blackburn, concerned in telomeres themselves, whereas Olovnikov's ideas were more general and universal, and in essence were an interpretation of already available experimental results, but not a bare hypothesis.

D) The first and very quick undo of the editing ("Was clear enough before.") emphasized the formal relation of the Editor to his work.

e) The removal of actual references to original articles under the pretext of "that were superseded by more recent and complete sources" deprives the paragraph of actual reinforcement, and the reader of access to the original source. Only 1 arcticle is in russian. — Preceding unsigned comment added by Vavilevskii (talk • contribs) 18:13, 14 March 2018 (UTC)

That's more history than Olovnikov deserves for theorizing about (not discovering) telomeres, as the Nobel prize and historical literature indicate. The content you added overpays Olovnikov's contribution, and the sources are neither the current understanding nor are they readable by the typical WP user. The current version reads:

"In the early 1970s, Russian theorist Alexei Olovnikov first recognized that chromosomes could not completely replicate their ends. Building on this, and to accommodate Leonard Hayflick's idea of limited somatic cell division, Olovnikov suggested that DNA sequences are lost every time a cell replicates until the loss reaches a critical level, at which point cell division ends." Sourced by PMID 27182535

This seems adequate acknowledgement of Olovnikov's role in the discovery. --Zefr (talk) 18:41, 14 March 2018 (UTC)

Reverse Complement

The article states that "the sequence of nucleotides in telomeres is AGGGTT,[1] with the complementary DNA strand being TCCCAA", but the actual reverse complement of AGGGTT is AACCCT. The complementary DNA strand is traditionally written in the same reading direction as the standard DNA strand. — Preceding unsigned comment added by 118.92.191.30 (talk) 07:21, 22 September 2019 (UTC)

Proposed addition to existing section ‘7. Measurement’

Information to be added: Flow-FISH [1] is used to quantify the length of telomeres in human white blood cells. A semi-automated method for measuring the average length of telomeres with Flow FISH was published in Nature Protocols in 2006.

Explanation of issue: Additional available telomere measurement technique currently not mentioned, in the interests of providing an accurate overview this should be included in the first paragraph of section 7 alongside other methods

References supporting change: Baerlocher GM, Vulto I, de Jong G, Lansdorp PM. Flow cytometry and FISH to measure the average length of telomeres (flow FISH). Nat Protoc 2006; 1:2365–2376. https://www.nature.com/articles/nprot.2006.263#B23

JLRD309 (talk) 18:23, 20 July 2020 (UTC)