Question

1. Transposable elements make up more than 40% of the human genome and are inserted more-or-less randomly throughout the genome. These elements are rare at the four homeobox gene clusters (HoxA, B, C, andD) along with an equivalent region of chromosome 22, which lacks a Hoxcluster.  Each cluster is about 100 kb in length and contains 9-11 genes.  Why would transposable elements be so rare then in these clusters?

Answer 1

Hox genes encode homeodomain transcription factors that takes part in development and shaping animal morphology. This is why they are highly conserved,because any mutation or insertion of a transposable element would end up a deleterious organism. So selection keeps this genes conserved as the organism would not be able to develop normally if they are altered.