A PCR survey for posterior Hox genes in amphibians

• Published in: Molecular phylogenetics and evolution Vol. 38; no. 2; pp. 449 - 458
• Main Authors: Mannaert, An, Roelants, Kim, Bossuyt, Franky, Leyns, Luc
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2006
• Subjects: Amino Acid Sequence; Amphibia; Amphibians - genetics; Animals; Anura; Caudata; Genes, Homeobox - genetics; Homeodomain Proteins - classification; Homeodomain Proteins - genetics; Hox genes; Humans; Limb evolution; Mice; Molecular Sequence Data; PCR survey; Polymerase Chain Reaction; Amphibia; Limb evolution; Hox genes; PCR survey
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2005.08.012

Hox genes encode transcription factors that play a key role in specifying the body plan in metazoans and are therefore essential in explaining patterns of evolutionary diversity. As an ancient tetrapod group with diverse limb types, amphibians are important for understanding the origin and diversification of limbs in land vertebrates. We conducted a PCR survey in two species of each amphibian order to identify Hox-9 to Hox-13, known to function in limb development. Fifteen distinct posterior Hox genes and one retro-pseudogene were identified, and the former confirm the existence of four Hox clusters in each amphibian order. Some genes expected to occur in all tetrapods, based on the posterior Hox complement of mammals, fishes and coelacanth, were not recovered from our survey, and may have been lost. Hoxd-12 is absent in frogs and possibly other amphibians. Considering its function in autopodial development, the loss of this gene may be related to the absence of the fifth finger in frogs and salamanders.