Gene Expression

[Ajay]

Diploid Chromosomes make up Human genetic content and hence what are the factors that determine the expression of maternal or paternal genes. If the reason is dominance, are there specific traits for any attribute which are considered to be dominant in humans ?

[JackBean]

The factors are called promotor, transcription factors, packing of chromatin.

[Ajay]

Does that mean that if a maternal promoter sequence is stronger than the paternal the maternal gene is expressed ? Regarding the chromatin packaging, epigenetic factors (in which there are numerous probabilities possible) are the reason ? If epigenetic factors are the reason for chromatin packaging one would not be able to predict based on sequence information right ?

[mith]

if you have two genes and two promotors, both have a chance of being expressed unless a product of one inhibits the transcription of the other.

[JackBean]

Actually epigenetics is the only factor, which can totally turn off some gene, look e.g. for X chromosome.
Although they will have different promotors, probably won't be any turned for 100% off, just the expression will be different

[Ajay]

If I wanted to know the exome of a genome, is there any specific assays for it ? Will that assay exactly pinpoint the DNA sequences taking part in gene expression (for e.g. 1% of the whole human genome) ?

[JackBean]

What's exome? All exones?
Just look for CDSs or mRNAs/cDNAs

[jwalin]

i think it does mean the dominant allele has a stronger promoter

that's what i think.

[JackBean]

dominance of allele and strength of promotor has nothing common

[kolean]

dominance of allele and strength of promotor has nothing common

Are you sure about this comment? 'nothing' in common at all? No possiblility that a strong promoter can cause an allele to be dominant in its expression?

[jwalin]

now guys please post stuff that you are 100% sure of. i am getting confused. why doesn't a stronger promoter mean a dominant allele?

[JackBean]

kolean: imagine one allele, which is truncated, but has strong promotor and other one, which has weak promotor, but the polypeptide is functional. Do you really think, that the first one will be dominant?
I don't say, that there can't be some relevance, but it's more about co-dominance, than dominance/recessivity. That is achieved by the polypeptide.