How do hox genes play an important role on body patterning in mammalian embryos?

Question

How do hox genes play an important role on body patterning in mammalian embryos?

Answer 1

I did lots of work on this so if you want more info let me know.

Hox genes are transcription factors that regulate downstream TF's such as hedge hog or sox & many others.  They are conserved in a anterior to posterior order amongst many species (very imp).  They are expressed in the A-P axis and their anterior axis is very strict but the posterior is not meaning you get overlapping expression of different HOX genes, which activates different threshold levels of other genes (as HOX genes are tF's) and which eventually gives rise to different tissues.  So they are conserved in this A-P order because if they werent, the diffusion of TF from A -->P wouldnt occur in the right amounts and the threshold levels would be different resulting in different tissues forming where they are not supposed to.  Evidence of this occurs when they knockout a certain HOX gene they get different tissues forming.

take a look at part a here and you'll see the segments i was talking about:

http://www.nybooks.com/images/tables/200...

I've put a link from google in the sources for further reading if you're interested.  It explains it

Answer 2

The HOX proteins which they encode are master regulators of embryonic development and continue to be expressed throughout postnatal life by affecting the expression of other genes.