Question

Explain the following sentences in term of redundancy post duplication for the Hox10 genes “Mice with only five mutant alleles display a 14th rib and altered sacral process, but the axial morphology is much less severely affected than in the Hox10 triple mutant (see figure 1 p). Combinations of any five of the six mutant alleles in the Hox10 paralogous group demonstrate similar mutant phenotypes to one another, indicating the approximately equal contribution of these alleles to axial patterning”

Answer 1

ANS) When a multiple genes perform a same function present in the genome of an organism is called gene redundancy is caused due to gene duplication also called paralogous genes , in case for any mutation in a gene there is a little effect on its phenotype due to these. here, we explain these sentence by giving an example of Hox10 genes.

           Hox 10 genes are key regulators of morphology along the axial skeleton, Its function in patterning the vertebrate axial skeleton and might play a role in vertebrate axial patterning.The phenotypes of these “five allele mutants” mice were similar due to genome duplication during evolution, resulting in a HOX genes some genes are then expressed but only in the forebrain and in that order regions in the axial domain such as vertebrae, ribs, and muscles.. Hox10 genes repress rib formation posterior to the thoracic vertebrae and are the only axial phenotype that has not been clearly shown to be Hox dependent which represent a developmental, and perhaps evolutionary state. The important roles of Hox genes in axial patterning, phenotypes in mutants.such as cessation of 14th rib formation at L1 by Hox10 genes.The remarkable phenotype in these mutant mice is the complete absence of rib formation in the thoracic region, a function consistent with the endogenous Hox10 function of repressing rib formation in the lumbosacral region.