Placement of chromosomes from each parent on dna

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In sexually reproducing organisms, DNA does not form a single continuous chain from one parent to another; rather, homologous chromosomes exist as two distinct strands that are independent of each other. During the G0 or G1 phases, DNA is wrapped around nucleosomes, resulting in a complex structure known as chromatin, which does not allow for a clear organization of chromosomes within the nucleus. Recent research indicates that chromatin is spatially organized into "chromatin territories" during interphase, where certain chromosomes may localize near one another. However, the territories of homologous chromosomes in mammalian cells are generally not adjacent, suggesting a level of spatial separation. This organization may influence gene expression, although the specifics can vary across different cell types.
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is dna in a sexually reproducing organism one single chain with dna from one parent coming first,with the other parent's dna joining it as it ends.or do the two strands lie side by side,without joining.Or do they lie side by side and join at some point?

the purpose of asking the question is to know whether homologous chromosomes lie close to each other or are distant from each other??
 
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ARAVIND113122 said:
is dna in a sexually reproducing organism one single chain with dna from one parent coming first,with the other parent's dna joining it as it ends.or do the two strands lie side by side,without joining.Or do they lie side by side and join at some point?

the purpose of asking the question is to know whether homologous chromosomes lie close to each other or are distant from each other??

DNA in the G0 or G1 phases is wrapped around nucleosomes and exists in the form of chromatin threads. This is a tangled mess; the chromosomes aren't neatly organised in rows and columns inside the nucleus, so saying that the chromosomes lie close together or far apart doesn't actually make sense. No homologous chromosomes are not joined together either; they are two different strands independent of each other.
 
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mishrashubham said:
DNA in the G0[/sun] or G1 phases is wrapped around nucleosomes and exists in the form of chromatin threads. This is a tangled mess; the chromosomes aren't neatly organised in rows and columns inside the nucleus, so saying that the chromosomes lie close together or far apart doesn't actually make sense.


New research actually suggests that the chromatin of different chromosomes are organized spatially within the nucleus. While the chromosomes do not display as much organization as they do when condensed during mitosis, during interphase, the chromosomes appear to localize to specific "chromatin territories" and researchers have often found that the territories of certain chromosomes often lie next to each other. The details of chromatin territory organization differ between cell types however. See the link at the bottom of the post for more details.

I'm not sure if anyone has looked at how the territories of homologous chromosomes are organized. Perhaps following some links from the site below can shed some light on the issue.

http://www.nature.com/scitable/topi...tories-the-arrangement-of-chromosomes-in-3025
 
Ygggdrasil said:
New research actually suggests that the chromatin of different chromosomes are organized spatially within the nucleus. While the chromosomes do not display as much organization as they do when condensed during mitosis, during interphase, the chromosomes appear to localize to specific "chromatin territories" and researchers have often found that the territories of certain chromosomes often lie next to each other. The details of chromatin territory organization differ between cell types however. See the link at the bottom of the post for more details.

I'm not sure if anyone has looked at how the territories of homologous chromosomes are organized. Perhaps following some links from the site below can shed some light on the issue.

http://www.nature.com/scitable/topi...tories-the-arrangement-of-chromosomes-in-3025

Intriguing! It'd be interesting to see how well defined these territories are and what effect this form of spatial organization within the nucleus has on gene expression. Also, according to this (link), territories of homologous chromosomes in mammalian cells are generally not adjacent.
 
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