Gene superfamily: homeo box proteins; (@CDX CHX10 CSX @DLX EMX1 EMX2 EN1 EN2 EVX1 EVX2 HLX1 HLXB9 HMX1 HMX2 HMX3 HOX11 HHEX @HOXA @HOXB @HOXC @HOXD ISL1 LMX1A LMX1B MEOX1 MEOX2 MSX1 MSX2 OTX1 OTX2 @PAX @PBX PMX1 PRHX)

SUM

[1] Homeo box-containing genes represent a major class of transcription factors directly involved in the regulation of embryogenesis. Most mammalian homeo box-containing genes reside in 4 distinct HOX clusters: HOXD in Chr 2q31, HOXA in Chr 7p1, HOXC in Chr 12q1, and HOXB in Chr 17q2. (Garcia-Fernandez-1994). Outside the 4 HOX clusters, more than 25 additional homeo box-containing genes have been reported in both vertebrate and invertebrate species. Extensive studies of the clustered and nonclustered homeo box genes suggest that the former evolved by local duplications of a single ancestral gene followed by larger duplications of chromosomal regions, whereas nonclustered homeo box genes appear to be derived by smaller gene duplication events followed by sequence divergence within the duplications of larger chromosomal regions. [2] The following single genes were also mapped: MSX1 (GEM:04p161/MSX1), CHX10, HOX11, EVX1, and EVX2. [3] Homologues of several murine (see GEM:09q341/SURF1:EAG and GEM:02q/EN1) and Drosophila homeosis genes (even-skipped; GEM:07p1/EVX1 and GEM:02q/EVX2) are also mapped in the human genome."

REF

REV,EVO,SEQ,FAG "Acampora D &: NAR, 17, 10385-10402, 1989 REV,EVO,FAG "Garcia-Fernandez J, Holland PWH: Nature, 370, 563-566, 1994 NOM "McAlpine PJ, Shows: Genomics, 7, N3, 460, 1990