BAGE genes generated by juxtacentromeric reshuffling in the Hominidae lineage are under selective pressure.
In this paper, we show that the BAGE (B melanoma antigen) gene family was generated by chromosome rearrangements that occurred during the evolution of hominoids. An 84-kb DNA fragment derived from the phylogenetic 7q36 region was duplicated in the juxtacentromeric region of either chromosome 13 or chromosome 21. The duplicated region contained a fragment of the MLL3 gene, which, after juxtacentromeric reshuffling, generated the ancestral BAGE gene. Then, this ancestral gene gave rise to several independent genes through successive rounds of inter- and intrachromosome duplications. Comparison of synonymous and nonsynonymous mutations in putative coding regions shows that BAGE genes, but not the BAGE gene fragments, are under selective pressure. Our data strongly suggest that BAGE proteins have a function and that juxtacentromeric regions, whose plasticity is now largely proved, are not a simple junkyard of gene fragments, but may be the birth site of novel genes.
Ruault
Myriam
M
Institut de Génétique Humaine, CNRS UPR 1142, 141, Rue de la Cardonille, 34396 Montpellier, France.
Ventura
Mario
M
Galtier
Nicolas
N
Brun
Marie-Elisabeth
ME
Archidiacono
Nicoletta
N
Roizès
Gérard
G
De Sario
Albertina
A
D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics*; D002503:Centromere / Q000235:genetics*; D002874:Chromosome Mapping; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics; D016000:Cluster Analysis; D017931:DNA Primers; D016521:Electrophoresis, Gel, Pulsed-Field; D020440:Gene Duplication; D015321:Gene Rearrangement / Q000235:genetics*; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D010802:Phylogeny; D012641:Selection, Genetic
D000951:Antigens, Neoplasm; C092706:BAGE protein, human; C490498:BAGE2 protein, human; C490497:BAGE3 protein, human; C490496:BAGE4 protein, human; C490495:BAGE5 protein, human; D017931:DNA Primers