short repetitive dna sequences

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Aggie2
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short repetitive dna sequences

Post by Aggie2 » Wed Nov 21, 2007 1:04 pm

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

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Bill

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mith
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Post by mith » Wed Nov 21, 2007 5:06 pm

Slippage in DNA replication if you're talking about satellites.
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Post by Aggie2 » Wed Nov 21, 2007 7:20 pm

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

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mith
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Post by mith » Wed Nov 21, 2007 7:27 pm

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

You can do a google search for satellite dna.
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Post by Aggie2 » Wed Nov 21, 2007 7:48 pm

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.
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Bill

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MrMistery
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Post by MrMistery » Thu Nov 22, 2007 8:26 am

well it depends. Fragile-X syndrome is caused by a short repetitive sequence of DNA.
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Post by Cristgonz » Thu Nov 22, 2007 2:21 pm

but maybe a large number of short repetitive dna sequences can be deleted in the rna's maturation ? deleted like introns?
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MrMistery
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Post by MrMistery » Thu Nov 22, 2007 7:43 pm

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.
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