Properties of Satellite Chromosomes

Question

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)

Answer 1

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.