Mutations in the Hox6 Paralogous Group do not Affect Diaphragm Development in Mice

Abstract

Hox genes play a major role in the development of animal body plans. They are highly conserved amongst the animal taxa, and are hypothesized to be the cause of the Cambrian Explosion 530 million years ago. Mutations in various Hox genes can lead to dramatic structural malformation and malfunction in animals. The Hox6 paralogous group is of particular interest because simultaneous mutations in all 3 Hox6 clusters leads to premature death shortly after birth in mice (Mus musculus). Based on the anterior to posterior patterning of the mammalian Hox genes (Figure 1), and the suspected location of Hox6 gene expression, it was hypothesized that Hox6 triple mutant mice died because of a misshapen or malformed diaphragm. Such a deficiency would prevent the newborn mice from inhaling, and death would occur via hypoxia. The purpose of this experiment was to determine if a poorly developed diaphragm was the cause of death of Hox6 triple mutant mice.