The Landscape of L1 Retrotransposons in the Human Genome Is Shaped by Pre-insertion Sequence Biases and Post-insertion Selection.
Mol Cell
; 74(3): 555-570.e7, 2019 05 02.
Article
em En
| MEDLINE
| ID: mdl-30956044
ABSTRACT
L1 retrotransposons are transposable elements and major contributors of genetic variation in humans. Where L1 integrates into the genome can directly impact human evolution and disease. Here, we experimentally induced L1 retrotransposition in cells and mapped integration sites at nucleotide resolution. At local scales, L1 integration is mostly restricted by genome sequence biases and the specificity of the L1 machinery. At regional scales, L1 shows a broad capacity for integration into all chromatin states, in contrast to other known mobile genetic elements. However, integration is influenced by the replication timing of target regions, suggesting a link to host DNA replication. The distribution of new L1 integrations differs from those of preexisting L1 copies, which are significantly reshaped by natural selection. Our findings reveal that the L1 machinery has evolved to efficiently target all genomic regions and underline a predominant role for post-integrative processes on the distribution of endogenous L1 elements.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Elementos de DNA Transponíveis
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Genoma Humano
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Retroelementos
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Elementos Nucleotídeos Longos e Dispersos
Limite:
Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article