Clusters of alpha satellite on human chromosome 21 are dispersed far onto the short arm and lack ancient layers
Authors
Ziccardi, WilliamZhao, Chongjian
Shepelev, Valery
Uralsky, Lev
Alexandrov, Ivan
Andreeva, Tatyana
Rogaev, Evgeny I.
Bun, Christopher
Miller, Emily
Putonti, Catherine
Doering, Jeffrey
UMass Chan Affiliations
Department of Psychiatry, Brudnick Neuropsychiatric Research InstituteDocument Type
Journal ArticlePublication Date
2016-09-01Keywords
acrocentric chromosomealpha satellite
centromere
chromosome 21
chromosome evolution
chromosome mapping
Genetics
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Show full item recordAbstract
Human alpha satellite (AS) sequence domains that currently function as centromeres are typically flanked by layers of evolutionarily older AS that presumably represent the remnants of earlier primate centromeres. Studies on several human chromosomes reveal that these older AS arrays are arranged in an age gradient, with the oldest arrays farthest from the functional centromere and arrays progressively closer to the centromere being progressively younger. The organization of AS on human chromosome 21 (HC21) has not been well-characterized. We have used newly available HC21 sequence data and an HC21p YAC map to determine the size, organization, and location of the AS arrays, and compared them to AS arrays found on other chromosomes. We find that the majority of the HC21 AS sequences are present on the p-arm of the chromosome and are organized into at least five distinct isolated clusters which are distributed over a larger distance from the functional centromere than that typically seen for AS on other chromosomes. Using both phylogenetic and L1 element age estimations, we found that all of the HC21 AS clusters outside the functional centromere are of a similar relatively recent evolutionary origin. HC21 contains none of the ancient AS layers associated with early primate evolution which is present on other chromosomes, possibly due to the fact that the p-arm of HC21 and the other acrocentric chromosomes underwent substantial reorganization about 20 million years ago.Source
Chromosome Res. 2016 Sep;24(3):421-36. Link to article on publisher's site Epub 2016 Jul 18.DOI
10.1007/s10577-016-9530-zPermanent Link to this Item
http://hdl.handle.net/20.500.14038/46252PubMed ID
27430641Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1007/s10577-016-9530-z
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