Homeobox

The term "homeobox" refers to a highly conserved DNA sequence, approximately 180 base pairs in length, found within genes that are involved in the regulation of development (morphogenesis) in animals, fungi, and plants. Genes containing a homeobox are called homeobox genes (often abbreviated as Hox genes in animals, particularly when referring to those arranged in clusters).

The homeobox encodes a protein domain of about 60 amino acids called the homeodomain. This homeodomain functions as a DNA-binding domain, allowing the protein to bind to specific sequences on DNA and regulate the expression of other genes. Homeobox genes act as transcription factors, controlling the transcription of target genes that specify cell fate and body plan during embryonic development.

The conservation of the homeobox sequence across diverse species suggests a fundamental role in developmental processes that has been maintained through evolutionary history. Mutations in homeobox genes can lead to significant developmental abnormalities, highlighting their critical function in establishing proper body organization. While traditionally associated with body plan development, homeobox genes have also been implicated in other cellular processes, including cell differentiation, proliferation, and apoptosis.