7 replies to this topic

[cardosopedro]

Hi.

I have a question that has been filling my mind. Probably I should know this, but...  

Is it frequent that a gene A have a regulatory role on the expression, transcription or function of gene B if A is just preceeding B in the genome? I mean, if in a given chromosome you have A followed by B, can A be regulating B by any means?


Thank you in advance.

[cardosopedro]

No suggestions?

[bob1]

Sure, A could be regulated by B directly or indirectly, but it is not necessarily the case.  I can't think of any examples off the top of my head though.

[cardosopedro]

Thanks for the answer. Of course it can be a coincidence that A regulates B and the genes are contiguous in the genome, but what I am asking if it is not a coincidence. I mean, is there a known genetic phenomenon through which A is a transcription factor for B?

[bob1]

I found this article which you might find interesting:

Identifying functional links between genes using conserved chromosomal proximity

Itai Yanai, Joseph C. Mellor and Charles DeLisi
TRENDS in Genetics Vol.18 No.4 April 2002

[HomeBrew]

The lacI gene (which produces a repressor protein) is contiguous with the Lac operon in E. coli, in that there are no genes between lacI and the lacXYA genes of the Lac operon.  It is constitutively expressed and blocks transcription of the Lac operon genes if there's no lactose around...

[cardosopedro]

bob1, I will read that paper, thanks.

HomeBrew, yes, I also remembered that and but I was wondering if that occurs not only in bacteria but also in eukaryotes, because my organism is an eukaryote.

[cardosopedro]

Very interesting the story about of the conserved chromosomal proximity. I have contacted the author for more info, but no answer until now. I definitely want to know if the phenomenon occurs not only in bacteria but also in eukaryotes, namely in fungi.

If anyone knows more about this please say something.