Any of a class of closely similar DNA sequences occurring in various genes and involved in regulating pattern formation, segmentation, and morphogenesis during embryonic development in many species.
See also: homeosis
Source: PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 764 (https://doi.org/10.1515/pac-2015-1202)