short repetitive dna sequences

[Aggie2]

When a large number of short repetitive dna sequences is detected on a chromosome (e.g., X), what does this indicate?

Thanks,
Bill

[mith]

Slippage in DNA replication if you're talking about satellites.

[Aggie2]

mith,

Thanks for the information. Now, if I could ask one more question: is there any idea what the functional significance of these short repeats is? How do they affect the phenotype of an organism?

Thanks, again.
Bill

[mith]

well you already know phenotypes are only affected by genes, which these probably are not.

You can do a google search for satellite dna.

[Aggie2]

mith,

You're right. I was thinking more along the lines of regulatory effects that this nuclear material might have on the genes present in the chromosome.
Thanks,
Bill

[MrMistery]

well it depends. Fragile-X syndrome is caused by a short repetitive sequence of DNA.

[Cristgonz]

but maybe a large number of short repetitive dna sequences can be deleted in the rna's maturation ? deleted like introns?

[MrMistery]

not quite. There are specific signals that make an intron an intron and direct it's splicing. Specific base sequences need to be present in order for the spliceosome to dock and to signal where to begin and end cutting. Also group 1,2 and 4 introns need similar signals, although groups 1 and 2 need to be able to self-splice.