HOX cluster Definition

"What was known as the Hox cluster in vertebrates and HOM-C (homeotic complex) in Drosophila has now been modified, such that this group of clustered genes is termed the HOX cluster in all species (i.e. vertebrates, insects, worms etc.). Hox as a gene name is restricted to vertebrates. Only genes in the HOX cluster can be named Hox genes." Thomas R. Burglin HOX pages

Useful references:

• Kappen, C., Schughart, K., Ruddle, F.H. (1993) Early evolutionary origin of major homeodomain sequence classes. Genomics, 18, 54-70.
• Scott, M.P., Tamkun, J.W., Hartzell III, G.W. (1989) The structure and function of the homeodomain. Biophys Acta, 989, 25-48.
• Gehring, W.J., Affolter, M., Burglin, T.R. (1994) Homeodomain proteins. Annu. Rev. Biochem., 63, 487-526.
• Schughart K; Kappen C; Ruddle FH Duplication of large genomic regions during the evolution of vertebrate homeobox genes. Proc Natl Acad Sci U S A 86: 7067-71 (1989)
• Kappen C; Schughart K; Ruddle FH Two steps in the evolution of Antennapedia-class vertebrate homeobox genes. Proc Natl Acad Sci U S A 86: 5459-63 (1989)