| Title | Chromosome 6 phylogeny in primates and centromere repositioning |
| Abstract | A panel of 15 human BAC/PAC probes, covering the entire chromosome 6, was used in FISH experiments on great apes and on representatives of Old World monkeys, New World monkeys, and lemurs to delineate the chromosome 6 phylogeny in primates. The domestic cat was used as an outgroup. The analysis showed a high marker order conservation, with few rearrangements required to reconcile the hypothesized chromosome 6 organization in primate ancestor with marker arrangement in all the examined species. Contrary to this simple evolutionary scenario, however, the centromere was found to be located in three distinct regions, without any evidence of chromosomal rearrangement that would account for its movement. One of the two centromere repositioning events occurred in great apes ancestor. The centromere moved from 6p22.1 to the present day location after the inversion event that differentiated marker order of the primate ancestor from the ancestor of Catarrhini. A cluster of intrachromosomal segmental duplications was found at 6p22.1, scattered in a region of about 9 Mb, which we interpret as remains of duplicons that flanked the ancestral centromere. Our data, therefore, suggest that some duplicon clusters found in noncentromeric/nontelomeric locations may represent traces of evolutionary silenced centromeres that inactivated after the occurrence of a centromere repositioning. In addition, the neocentromere emergence we have documented in Old World monkeys at 6q24.3 appears to have arisen and progressed without affecting the displaced flanking sequences. |
| Source | Molecular biology and evolution 20 (9), pp. 1506–1512 |
| Keywords | chromosome 6ancestral centromeresneocentromereschromosome evolution |
| Journal | Molecular biology and evolution |
| Editor | University of Chicago Press,, Chicago, Ill., Stati Uniti d'America |
| Year | 2003 |
| Type | Articolo in rivista |
| DOI | 10.1093/molbev/msg165 |
| Authors | Eder, V; Ventura, M; Ianigro, M;Teti, M; Rocchi, M; Archidiacono, N |
| Text | 341229 2003 10.1093/molbev/msg165 ISI Web of Science WOS 000185175500010 chromosome 6 ancestral centromeres neocentromeres chromosome evolution Chromosome 6 phylogeny in primates and centromere repositioning Eder, V; Ventura, M; Ianigro, M;Teti, M; Rocchi, M; Archidiacono, N DAPEG; object Object A panel of 15 human BAC/PAC probes, covering the entire chromosome 6, was used in FISH experiments on great apes and on representatives of Old World monkeys, New World monkeys, and lemurs to delineate the chromosome 6 phylogeny in primates. The domestic cat was used as an outgroup. The analysis showed a high marker order conservation, with few rearrangements required to reconcile the hypothesized chromosome 6 organization in primate ancestor with marker arrangement in all the examined species. Contrary to this simple evolutionary scenario, however, the centromere was found to be located in three distinct regions, without any evidence of chromosomal rearrangement that would account for its movement. One of the two centromere repositioning events occurred in great apes ancestor. The centromere moved from 6p22.1 to the present day location after the inversion event that differentiated marker order of the primate ancestor from the ancestor of Catarrhini. A cluster of intrachromosomal segmental duplications was found at 6p22.1, scattered in a region of about 9 Mb, which we interpret as remains of duplicons that flanked the ancestral centromere. Our data, therefore, suggest that some duplicon clusters found in noncentromeric/nontelomeric locations may represent traces of evolutionary silenced centromeres that inactivated after the occurrence of a centromere repositioning. In addition, the neocentromere emergence we have documented in Old World monkeys at 6q24.3 appears to have arisen and progressed without affecting the displaced flanking sequences. 20 Published version Articolo in rivista University of Chicago Press, 0737 4038 Molecular biology and evolution Molecular biology and evolution Mol. biol. evol. Molecular biology and evolution. MBE massimo.ianigro IANIGRO MASSIMO |
