What is Hox gene?
'''Hox genes''' are a group of related [[gene]]s that determine the basic structure and orientation of animals and plants.<ref>Dictionary.com – Hox gene [http://dictionary.reference.com/browse/Hox+gene]. Accessed March 31, 2011.</ref><ref>Jongmin Nam, Claude W. dePamphilis, Hong Ma, Masatoshi Nei. Antiquity and evolution of the MADS-Box gene family controlling flower development in plants. [https://academic.oup.com/mbe/article/20/9/1435/976862?login=false]</ref> 'Hox' is short for 'homeobox'. Hox genes are critical for the proper placement of [[Segmentation|segment structures]] of animals during early [[embryo]]nic development (e.g. legs, [[antenna]]e, and [[wing]]s in [[Drosophila|fruit flies]] or the different [[vertebrate]] [[rib]]s in humans).<ref>Gehring, Walter J. 1998. ''Master control genes in development and evolution. the homeobox story''. Yale University Press, New Haven CT.</ref> [[File:Hox cluster.svg|thumb|center|400px|simple collinearity diagram]] [[File:Hoxgenesoffruitfly.svg|Homeobox gene expression in ''Drosophila melanogaster''|thumb|center|400px]] Hox genes are a complex of [[gene]]s whose [[protein]]s bind to the regulatory regions of target genes. The target genes then activate or repress [[cell]] processes to direct the final development of the organism.<ref>Lewis E.B. 1995. The ''bithorax'' complex: the first fifty years. [[Nobel Prize]] lecture. Repr. in Ringertz N. (ed) 1997. ''Nobel lectures, Physiology or Medicine''. World Scientific, Singapore.</ref><ref>Lawrence P. 1992. ''The making of a fly''. Blackwell, Oxford.</ref> *Hox genes have a [[DNA]] sequence known as the '''homeobox'''. The homeobox is a 180 [[nucleotide]]-long [[DNA]] sequence which codes for a 60 [[amino acid]]-long [[protein]] domain known as the ''homeodomain''. This works by binding with DNA. *Hox genes are in gene clusters on the [[genome]] *The order of the [[Locus (genetics)|loci]] in the [[chromosome]] parallels the order in which the loci are expressed in [[segment]]s along the body.<ref>{{cite journal | a