Hox genes

A family of homeobox transcription factors that specify position information along the body axis. The homeobox gene was the first developmental gene to be identified, and hox genes are its product.  They are defined by a specific sequence of amino acids and nucleotides (the homeobox) that allows them to bind to specific regions of DNA and thereby control transcription of these target genes.  In this way, vertebrate Hox genes help control the craniocaudal (i.e., head-to-tail axis) segmentation of neural and non-neural structures (i.e., they specify position information).  Hox genes are part of the Antennapedia gene sub-family originally identified in the fruit fly, which controls placement of the legs.   

See Homeodomain proteins and homeobox genes, Limb bud, Morphogenetic field, Organizer (embryology), Proteins, Reelin, Segment polarity, Segmentation