Talk:Minisatellite

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Isn't this synonymous with "VNTR" (variable number tandem repeat) ?.. Or are they different?

--Hughitt1 04:25, 18 December 2005 (UTC)

microsatellites and minisatellites

Aren't they the same thing? I'd really appreciate if someone defines on each page the difference between those two and VNTR if there are any

Microsatellites and minisatellites

24.18.234.112 (talk)These sequences are both tandem repeated segments of DNA. The only difference is the length of the repeated subunit. When the subunit is between 1 and 9 basepairs, it is called a microsatellite. Minisatellites are composed of longer subunits of at least 10 base pairs in length. For example ATATATATATATATATAT can be written (AT)n and is a microsatellite. A minisatellite might be something like (AGGCGAGGGTTG)n. The minimum number of repeats required to be considered a "satellite" varies, depending on the type (eg. (AT)n versus (ATTTTTTTTTT)n). Generally, the subunit must be repeated at least 6 times to be considered a tandem repeat. See http://tandem.bu.edu/trf/trf.html. I hope this helps, I do not usually edit wiki entries. 24.18.234.112 (talk) 00:17, 22 June 2010 (UTC)

Microsatellites are shorter repeats, most typically 1-2 basepairs long. Microsatellites are caused by repeat slippage which is limited to offsets of only a couple of bases.

"1 basepair long" microsatellite does not make very much sense, it's a single nucleotide run. Most microsatellites are 2-4 bp long —Preceding unsigned comment added by 151.141.84.173 (talk) 23:20, 14 January 2009 (UTC)

micro and mini

Ellegren, 2004 has a nice little explanation:

What is a microsatellite? Genomes are scattered with simple repeats. Tandem repeats occur in the form of iterations of repeat units of almost anything from a single base pair to thousands of base pairs.Mono-, di-, triand tetranucleotide repeats are the main types of microsatellite, but repeats of five (penta-) or six (hexa-) nucleotides are usually classified as microsatellites as well. Repeats of longer units form minisatellites or, in the extreme case, satellite DNA. The term satellite DNA originates from the observation in the 1960s of a fraction of sheared DNA that showed a distinct buoyant density, detectable as a ‘satellite peak’ in DENSITY GRADIENT CENTRIFUGATION, and that was subsequently identified as large centromeric tandem repeats.When shorter (10–30-bp) tandem repeats were later identified, they came to be known as minisatellites. Finally,with the discovery of tandem iterations of simple sequence motifs, the term microsatellites was coined. The difference between the terms micro- and minisatellites might not be obvious per se, but it is motivated by the difference in the mutational mechanisms of repeats of just a few nucleotides and of ten or more —Preceding unsigned comment added by 59.167.67.245 (talk) 05:05, 18 April 2008 (UTC)

==Funny Memory hook==

"Pure as gold" and "cut the pie" may be funny memory hooks, but why are the in the article "microsatellites", not in "Nucleic acid"? 134.2.164.11 (talk) 19:42, 9 December 2008 (UTC)

First time used

What on earth is that paragraph doing? its incredibly poorly written, Im not going to attempt to re-write it as I dont know enough about the case but I think it needs either removed or completely re-written —Preceding unsigned comment added by 192.173.4.218 (talk) 13:38, 3 May 2009 (UTC)

a conclusion

-this is my own understanding and not copied from a source-

So we can say that variability is at the centromere (where he said Hypervariable minisatellites have 9-64 core), but the highest mutation is almost related to the telomere (he didn't specify location, actually he only estimate highly-mutablility to be ~1% , but earlier said that 90% of all minisatellite are at the telomere --> so the sub-group (= most mutable repeats) will similarly occur at the telomere ....

I will write down how I understood it:

the simple thing is a sequence that getting repeated (called minisatellite) let's go one step beyond that: the repetition itself "VARY" ((I think this is what he called internal variation of repeat.))

these variation divided into two types:

1)the variation in somatic cell, & 2)in the germ cell

let's take the 1st: in somatic cell: variation is (intra-allel) and caused by slippage of the transcriptase

2) in germ cell the variation called (inter-allel) and it is due to crossover ((I remember crossover happens in germ cell meiosis)) now we have something here about the crossover: he says that crossover occur in certain areas ((he calls them: crossover hotspots)) these hotspots occur on either side of a minisatellite ((he said they flank the minisatellite))

and it seems that there is a controversy whether the minisatellite "trigger" DNA swap ((obviously swap in the flanking hotspots of crossover)) OR the crossover hotspots trigger the variation in the minisatellite (((may be both are correct, I guess I just mistakenly thought there is antagonism between the two ideas)))

then a paragraph talk about (fate) which is : until mutation in the flanking hotspots (stop crossover?) in fact he just said stop DNA recombination. and this result in extinction of the variation by meiosis ((here I am confused: did he means that the repeat lost through meiosis (extremely unlikely) OR he means that the "variation" will stop (so will stay constant) so no more variations done by meiosis ((because no more DNA recombination after hotspot got a mutation))

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it seems that some have pictured out the variation in the repeat ((seems that this picture is the basis for DNA fingerprinting)) ..... more over: they could say what changes have happened ((I think because if a 30 segments have the same sequence and only the 31 differ: this suggest that the 31st had the mutation)).... so studying the picture of the "variation" of these repeats they can: 1- make DNA finger-printing, and possibly the degree of matching between two sets of DNA ((check this))

2- predict a story about what have happened ((if all similar & one is different then the one is mutant, also may be:the center is old and periphery is new, I'm only speculating, you check it))

3- the mechanism of changes ((of course if he have stories of what happened to the allel (like mutations), then he can conclude some rules about these changes & mutations))

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in brief these minisatellite seems very important, and their study is very big thing, and have something to do with major field about the study of DNA like DNA fingerprinting.

although they are usually non-coding but some have been found to: -exist within a gene ((as far as I understood)) - affect transcription ((bind protein which can be transcription factor)) -I remember once I read : chromosomes get associated at these sites ((obviously when we have each two chromosomes comes together, I guess in the meiosis))

 — Preceding unsigned comment added by Yasir muhammed ali (talk • contribs) 15:17, 24 March 2016 (UTC)