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I have some questions regarding Satellite chromsomes which could not be resolved by a google search.

  1. Does the satellite consist of telomeric sequences ?

  2. If not, What is the function of a satellite ? And where will the telomeric sequences be present - in the main body ? On the secondary constriction ?

  3. Satellite chromosomes are also known as SAT chromosome which stands for Sino Acid Thymidine. I read in some sources that SAT means without thymidine. But how is that possible, if there is A then obviously there has to be T ? ( in dsDNA)

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  • $\begingroup$ I'm no expert but as far as I understand it, satellite sequences such as micro satellites are just repeating sequences of DNA (en.wikipedia.org/wiki/Satellite_DNA), which seems to satisfy telomere sequence repeats (en.wikipedia.org/wiki/Telomere). Satellite DNA is the main component of functional centromeres, and form the main structural constituent of heterochromatin (ref above). SAT chromosomes and presumably their sequences play a vital role in the formation of the nucleolus after cell division is completed (en.wikipedia.org/wiki/Satellite_chromosome). Not sure about 3 $\endgroup$ May 28, 2014 at 14:32

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If by "satellite chromosomes" you mean "satellite repeats", then:

  1. Not always. There many types of satellites, such as telomeric, centromeric (like gamma, alpha, beta satellites), simple repeats (CT)n.
  2. It is still an open question. Some say they are important for chromosome structure (e.g., centromeres). Sometimes satellites get transcribed as might act as lncRNAs. And of course, most of them are just junk DNA.
  3. If there is T then there is A too.

Edit

  1. Satellites contain telomeric repeats at their ends as all chromosomes do. But they are more about NOR repeats.

  2. They are important for the nucleolus functioning. But shorts arms of acrocentric chromosomes are not crucial, take Robertsonian translocation as an example.

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  • $\begingroup$ satellite chromesome and satellite dna are different. I mean satellite chromosome $\endgroup$
    – biogirl
    May 29, 2014 at 14:42
  • $\begingroup$ I edited my answer. $\endgroup$
    – pogibas
    May 29, 2014 at 15:07

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