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Alu element

About: Alu element is a research topic. Over the lifetime, 1826 publications have been published within this topic receiving 105845 citations. The topic is also known as: ALU elements.


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Journal ArticleDOI
01 Nov 1989-Genomics
TL;DR: It is found that most single base changes in up to 200-base fragments could be detected as mobility shifts and the interspersed repetitive sequences of human, Alu repeats are highly polymorphic.

3,625 citations

Journal ArticleDOI
12 Mar 2004-Science
TL;DR: Mobile elements within genomes have driven genome evolution in diverse ways and are becoming useful tools for learning more about genome evolution and gene function.
Abstract: Mobile elements within genomes have driven genome evolution in diverse ways. Particularly in plants and mammals, retrotransposons have accumulated to constitute a large fraction of the genome and have shaped both genes and the entire genome. Although the host can often control their numbers, massive expansions of retrotransposons have been tolerated during evolution. Now mobile elements are becoming useful tools for learning more about genome evolution and gene function.

1,797 citations

Journal ArticleDOI
TL;DR: The complete genomic sequences of human chromosomes 21 and 22 are used to examine the properties of CpG islands in different sequence classes by using a search algorithm that is compatible with the recent detection of 5-methylcytosine in Drosophila, and might suggest that S. cerevisiae has, or once had, C pG methylation.
Abstract: CpG islands are useful markers for genes in organisms containing 5-methylcytosine in their genomes. In addition, CpG islands located in the promoter regions of genes can play important roles in gene silencing during processes such as X-chromosome inactivation, imprinting, and silencing of intragenomic parasites. The generally accepted definition of what constitutes a CpG island was proposed in 1987 by Gardiner-Garden and Frommer [Gardiner-Garden, M. & Frommer, M. (1987) J. Mol. Biol. 196, 261–282] as being a 200-bp stretch of DNA with a C+G content of 50% and an observed CpG/expected CpG in excess of 0.6. Any definition of a CpG island is somewhat arbitrary, and this one, which was derived before the sequencing of mammalian genomes, will include many sequences that are not necessarily associated with controlling regions of genes but rather are associated with intragenomic parasites. We have therefore used the complete genomic sequences of human chromosomes 21 and 22 to examine the properties of CpG islands in different sequence classes by using a search algorithm that we have developed. Regions of DNA of greater than 500 bp with a G+C equal to or greater than 55% and observed CpG/expected CpG of 0.65 were more likely to be associated with the 5′ regions of genes and this definition excluded most Alu-repetitive elements. We also used genome sequences to show strong CpG suppression in the human genome and slight suppression in Drosophila melanogaster and Saccharomyces cerevisiae. This finding is compatible with the recent detection of 5-methylcytosine in Drosophila, and might suggest that S. cerevisiae has, or once had, CpG methylation.

1,553 citations

Journal ArticleDOI
25 Sep 2014-Cell
TL;DR: It is demonstrated that exon circularization is dependent on flanking intronic complementary sequences in human introns and that alternative formation of inverted repeated Alu pairs can lead to alternative circularization, resulting in multiple circular RNA transcripts produced from a single gene.

1,451 citations

Journal ArticleDOI
TL;DR: The genomic analysis of miRNAs in the human chromosome 19 miRNA cluster (C19MC) revealed that they are interspersed among Alu repeats, and these findings extend the current view of miRNA origins and the transcriptional machinery driving their expression.
Abstract: Prior work demonstrates that mammalian microRNA (miRNA or miR) expression requires RNA polymerase II (Pol II). However, the transcriptional requirements of many miRNAs remain untested. Our genomic analysis of miRNAs in the human chromosome 19 miRNA cluster (C19MC) revealed that they are interspersed among Alu repeats. Because Alu transcription occurs through RNA Pol III recruitment, and we found that Alu elements upstream of C19MC miRNAs retain sequences important for Pol III activity, we tested the promoter requirements of C19MC miRNAs. Chromatin immunoprecipitation and cell-free transcription assays showed that Pol III, but not Pol II, is associated with miRNA genomic sequence and sufficient for transcription. Moreover, the mature miRNA sequences of approximately 50 additional human miRNAs lie within Alu and other known repetitive elements. These findings extend the current view of miRNA origins and the transcriptional machinery driving their expression.

1,433 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202320
202279
202134
202046
201942
201858