Homothorax

{{Short description|Arthropod gene}}

{{Distinguish|Hemothorax}}

Homothorax (HTH or HTX) is a transcriptional co-factor to Hox genes that is closely connected with extradenticle.{{Cite web

| url = http://www.sdbonline.org/fly/gene/homthrx1.htm| title = Interactive Fly, Drosophila}} It may play a role in the identification of segments during panarthropod development.{{Cite journal | last1 = Moczek | first1 = A. P. | last2 = Rose | first2 = D. J. | title = Differential recruitment of limb patterning genes during development and diversification of beetle horns | journal = Proceedings of the National Academy of Sciences | volume = 106 | issue = 22 | pages = 8992–7 | year = 2009 | doi = 10.1073/pnas.0809668106 | pmid=19451631 | pmc=2690047| doi-access = free }} The gene acts in a similar way across the panarthropod phyla, although its expression pattern is reversed in the millipedes, centipedes and crustaceans.{{Cite journal | last1 = Janssen | first1 = R. | last2 = Eriksson | first2 = B. J. | last3 = Budd | first3 = G. E. | last4 = Akam | first4 = M. | last5 = Prpic | first5 = N. M. | title = Gene expression patterns in an onychophoran reveal that regionalization predates limb segmentation in pan-arthropods | journal = Evolution & Development | volume = 12 | issue = 4 | pages = 363–72 | year = 2010 | doi = 10.1111/j.1525-142X.2010.00423.x | pmid = 20618432 | s2cid = 27770103 | url = http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-135134 }}