HOX genes

Hox genes are a superfamily of genes that specify an organism’s body plans. Within the protein made by the HOX genes, there is a homeobox domain is a domain that controls anatomical development in eukaryotes. In animals, there are 16 major classes of homeodomains. HOX genes were originally discovered in 1994 in fruit flies. The HOX gene is especially important in the regulation of development. A mutation in the HOX gene can have a crippling effect on the development, often resulting in physical disorganizes or termination of pregnancy. Because HOX genes are most vital to the development of the fetus, the HOX gene is mostly conserved across species. A mutation in HOX gene that gets fixed in a population can result in a completely new plan such as those that are present in snakes. In snakes, they specifically have a mutation in the HOX6 gene which causes the snake to lose the forelimb. Because of this, snakes have a widely different body plan compared to those of its close relatives who have forelimbs. In labs, hox gene regulation and expression can be manipulated to make certain body parts grow where there normally isn’t a certain body part. The most famous example of this is in fruit flies where researchers caused legs to grow where the eyes should be by manipulating a hox gene called antp. Experiments show the importance of HOX gene in maintaining the general structure of the body plan.