The homeobox genes encode a highly conserved family of transcription factors that play an important role in morphogenesis in all multicellular organisms.

The product of the mouse Hoxd13 gene plays a role in axial skeleton development and forelimb morphogenesis.

[9] Experiments investigating the impact of 5′ Hoxd overexpression in zebrafish embryos observed modified development of distal fin structures, resulting in increased proliferation, distal expansion of cartilage tissue and fin fold reduction.

[10] A number of similar studies conducted with a range of animals, including catsharks[11] and marsupials,[12] lend further credibility to the role of the Hoxd13 gene in the fin-to-limb transition.

[13] This article incorporates text from the United States National Library of Medicine, which is in the public domain.