Hox Genes and Early Evolution of Vertebrate Limbs As part of the genetic network, Hox genes operate on the molecular level to determine the placement of bodily parts on a living organism. “ Hox ” is a contraction of “ homeobox ,” which are pairs of DNA sequence inside a gene. Hox genes are regulatory, in that they regulate what other genes do and how they work together to form complex structures. Hox genes are positional signaling molecules; for example, specific Hox genes determine where, when, and how limb buds will form on the embryonic structure. Although the exact molecular mechanism or operation is not yet entirely understood, studies indicate that Hox genes may interact with other signaling chemicals; Tickle, for example, suggests...The end:
.....dage Expression Driven by the Hoxd Global Control Region is an Ancient Gnathostome Feature.” PNAS. (June, 2011): Retrieved November 16, 2011 from <http://www.pnas.org/content/108/31/12782.full> Tickle, Cheryll . “Developmental Cell Biology: Making Digit Patterns in the Vertebrate Limb.” Nature Reviews Molecular Cell Biology 7, (January 2006): 45-53. Wang, Zhe , et al. “Adaptive Evolution of 5′HoxD Genes in the Origin and Diversification of the Cetacean Flipper.” Oxford Journal. (December, 2008): Retrieved November 16, 2011 from <http://mbe.oxfordjournals.org/content/26/3/613.full> Zakany J, Duboule D. “The role of Hox Genes During Vertebrate Limb Development.” Current Opinion in Genetic Development. 17.4 (August, 2007): 359-366.