🚀 go-pugleaf

Greg Dressler (greg.dressler) wrote:

: You are entirely correct in your analysis of position effects and locus
: control regions.  However, from a geneticists point of view a gene
: encompasses more than just the coding region and would include all
: elements necessary for correct expression.   It is clear to me that some
: of these cis elements are located far from the actual coding region.  Note
: that some genes are more than 1 megabase in size.  

Well, an all encompassing definition for a "gene" is controversial. 
Certain distal regulatory elemants such as enhancers may affect more than 
one gene product, so it is difficult to include them as part of the gene 
since they are doing double duty. A definition of a gene needs to take 
into effect that the gene product doesn't necessarily have to be 
translated to do its job (certain genes like XIST <I think> act as RNAs). 

: I was only trying to explain in very simple terms that the position on a
: genetic map generally does not affect the expression pattern.  From the
: original questions asked, I think the student has some fundamental
: misunderstandings of genetics that may be addressed in more simple rather
: than complex terms.

You are right, the original author probably was only asking for 
explanations in basic terms. I just got caught up in the resultant 
nitpicking since I am in the process of trying to earn a PhD in genetics 
and it is a fun way of making a little use of the knowledge they keep 
stuffing in my head ;)

Gregory S. Turenchalk