title: Independent centromere formation in a capricious, gene-free domain of chromosome 13q21 in Old World monkeys and pigs.
abstract: BACKGROUND
  Evolutionary centromere repositioning and human analphoid neocentromeres occurring in clinical cases are, very likely, two stages of the same phenomenon whose properties still remain substantially obscure. Chromosome 13 is the chromosome with the highest number of neocentromeres. We reconstructed the mammalian evolutionary history of this chromosome and characterized two human neocentromeres at 13q21, in search of information that could improve our understanding of the relationship between evolutionarily new centromeres, inactivated centromeres, and clinical neocentromeres.
  
  
  RESULTS
  Chromosome 13 evolution was studied, using FISH experiments, across several diverse superordinal phylogenetic clades spanning >100 million years of evolution. The analysis revealed exceptional conservation among primates (hominoids, Old World monkeys, and New World monkeys), Carnivora (cat), Perissodactyla (horse), and Cetartiodactyla (pig). In contrast, the centromeres in both Old World monkeys and pig have apparently repositioned independently to a central location (13q21). We compared these results to the positions of two human 13q21 neocentromeres using chromatin immunoprecipitation and genomic microarrays.
  
  
  CONCLUSIONS
  We show that a gene-desert region at 13q21 of approximately 3.9 Mb in size possesses an inherent potential to form evolutionarily new centromeres over, at least, approximately 95 million years of mammalian evolution. The striking absence of genes may represent an important property, making the region tolerant to the extensive pericentromeric reshuffling during subsequent evolution. Comparison of the pericentromeric organization of chromosome 13 in four Old World monkey species revealed many differences in sequence organization. The region contains clusters of duplicons showing peculiar features.
authors.affiliation: Department of Genetics and Microbiology, University of Bari, Bari, Italy.
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Cardone
authors.forename: Alicia
authors.initials: A
authors.lastname: Alonso
authors.forename: Michele
authors.initials: M
authors.lastname: Pazienza
authors.forename: Mario
authors.initials: M
authors.lastname: Ventura
authors.forename: Gabriella
authors.initials: G
authors.lastname: Montemurro
authors.forename: Lucia
authors.initials: L
authors.lastname: Carbone
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: de Jong
authors.forename: Roscoe
authors.initials: R
authors.lastname: Stanyon
authors.forename: Pietro
authors.initials: P
authors.lastname: D'Addabbo
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Archidiacono
authors.forename: Xinwei
authors.initials: X
authors.lastname: She
authors.forename: Evan E
authors.initials: EE
authors.lastname: Eichler
authors.forename: Peter E
authors.initials: PE
authors.lastname: Warburton
authors.forename: Mariano
authors.initials: M
authors.lastname: Rocchi
mesh_terms: D000818:Animals; D002503:Centromere / Q000235:genetics* / Q000648:ultrastructure; D002520:Cercopithecidae / Q000235:genetics*; D002843:Chromatin / Q000235:genetics; D002874:Chromosome Mapping; D004606:Elephants / Q000235:genetics; D019143:Evolution, Molecular; D020440:Gene Duplication; D005819:Genetic Markers; D015186:Hominidae / Q000235:genetics; D006736:Horses / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D020411:Oligonucleotide Array Sequence Analysis; D013552:Swine / Q000235:genetics*
chemical_list: D002843:Chromatin; D005819:Genetic Markers