Hominy grits

Homeotic genes are a group of genes that control the development of the body plan of an organism. They are responsible for determining the identity of body parts and structures during embryonic development. Homeotic genes are found in a wide range of organisms, from fruit flies to humans, and they share a common sequence of DNA known as the homeobox.

Function

Homeotic genes encode transcription factors that control the expression of other genes. They are expressed in a specific spatial and temporal pattern during embryonic development. The proteins they produce bind to specific DNA sequences, regulating the transcription of target genes. This regulation influences the development of body segments and structures.

Homeobox

The homeobox is a DNA sequence found within genes that are involved in the regulation of patterns of anatomical development (morphogenesis) in animals, fungi and plants. Genes that have a homeobox are called homeobox genes and form the homeobox gene family.

Discovery

Homeotic genes were first discovered in fruit flies during studies of mutations that resulted in dramatic transformations of body parts. For example, a mutation in a homeotic gene might result in the growth of a leg where an antenna should be. These discoveries led to the realization that similar genes exist in all multicellular organisms, including humans.

Hox genes

In many animals, homeotic genes are organized into clusters known as Hox genes. Hox genes determine the head-to-tail body axis in animals. They are arranged in the same order on the chromosome as the body parts they affect, a phenomenon known as colinearity.

Clinical significance

Mutations in homeotic genes can lead to serious developmental disorders. For example, mutations in the human HOX genes can result in malformations of the spine, limbs, and other body parts.

See also

• Genetics
• Developmental biology
• Molecular biology