The genomic structure of a human chromosome 22 nucleolar organizer region determined by TAR cloning.

Autor: Kim JH; Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD, 20892, USA., Noskov VN; Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD, 20892, USA., Ogurtsov AY; National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, 20892, USA., Nagaraja R; Laboratory of Genetics and Genomics, National Institute on Aging, Baltimore, MD, 21224, USA., Petrov N; Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD, 20892, USA., Liskovykh M; Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD, 20892, USA., Walenz BP; Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, MD, 20892, USA., Lee HS; Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD, 20892, USA., Kouprina N; Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD, 20892, USA., Phillippy AM; Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, MD, 20892, USA., Shabalina SA; National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, 20892, USA. shabalin@ncbi.nlm.nih.gov., Schlessinger D; Laboratory of Genetics and Genomics, National Institute on Aging, Baltimore, MD, 21224, USA. schlessingerd@mail.nih.gov., Larionov V; Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD, 20892, USA. larionov@mail.nih.gov.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2021 Feb 04; Vol. 11 (1), pp. 2997. Date of Electronic Publication: 2021 Feb 04.
DOI: 10.1038/s41598-021-82565-x
Abstrakt: The rDNA clusters and flanking sequences on human chromosomes 13, 14, 15, 21 and 22 represent large gaps in the current genomic assembly. The organization and the degree of divergence of the human rDNA units within an individual nucleolar organizer region (NOR) are only partially known. To address this lacuna, we previously applied transformation-associated recombination (TAR) cloning to isolate individual rDNA units from chromosome 21. That approach revealed an unexpectedly high level of heterogeneity in human rDNA, raising the possibility of corresponding variations in ribosome dynamics. We have now applied the same strategy to analyze an entire rDNA array end-to-end from a copy of chromosome 22. Sequencing of TAR isolates provided the entire NOR sequence, including proximal and distal junctions that may be involved in nucleolar function. Comparison of the newly sequenced rDNAs to reference sequence for chromosomes 22 and 21 revealed variants that are shared in human rDNA in individuals from different ethnic groups, many of them at high frequency. Analysis infers comparable intra- and inter-individual divergence of rDNA units on the same and different chromosomes, supporting the concerted evolution of rDNA units. The results provide a route to investigate further the role of rDNA variation in nucleolar formation and in the empirical associations of nucleoli with pathology.
Databáze: MEDLINE
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