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- Guibert, Sylvain, et al.
(författare)
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CTCF-binding sites within the H19 ICR differentially regulate local chromatin structures and cis-acting functions
- 2012
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 7:4, s. 361-369
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Tidskriftsartikel (refereegranskat)abstract
- It is generally assumed that CTCF-binding sites are synonymous with the demarcation of expression domains by promoting the formation of chromatin loops. We have proposed earlier, however, that such features may be context-dependent. In support of this notion, we show here that chromatin loop structures, impinging on CTCF-binding sites 1/2 and 3/4 at the 5' and 3'-ends, respectively, within the maternal allele of the H19 imprinting control region (ICR), differ significantly. Although abrogation of CTCF binding to the maternal H19 ICR allele results in loss of chromatin loops in the 3'-region, there is a dramatic gain of long-range chromatin loops impinging on the 5'-region. As the degree of occupancy of its four CTCF-binding sites discriminates between the chromatin insulator and replication timing functions, we submit that the CTCF-binding sites within the H19 ICR are functionally diverse and organize context-dependent higher order chromatin conformations.
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| 2. |
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| 3. |
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| 4. |
- Sandhu, Kuljeet Singh, et al.
(författare)
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Nonallelic transvection of multiple imprinted loci is organized by the H19 imprinting control region during germline development
- 2009
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Ingår i: Genes & Development. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 23:22, s. 2598-2603
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Tidskriftsartikel (refereegranskat)abstract
- Recent observations highlight that the mammalian genome extensively communicates with itself via long-range chromatin interactions. The causal link between such chromatin cross-talk and epigenetic states is, however, poorly understood. We identify here a network of physically juxtaposed regions from the entire genome with the common denominator of being genomically imprinted. Moreover, CTCF-binding sites within the H19 imprinting control region (ICR) not only determine the physical proximity among imprinted domains, but also transvect allele-specific epigenetic states, identified by replication timing patterns, to interacting, nonallelic imprinted regions during germline development. We conclude that one locus can directly or indirectly pleiotropically influence epigenetic states of multiple regions on other chromosomes with which it interacts.
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| 5. |
- Zhao, Zhihu, et al.
(författare)
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Circular chromosome conformation capture (4C) uncovers extensive networks of epigenetically regulated intra- and interchromosomal interactions
- 2006
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 38:11, s. 1341-1347
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating evidence converges on the possibility that chromosomes interact with each other to regulate transcription in trans. To systematically explore the epigenetic dimension of such interactions, we devised a strategy termed circular chromosome conformation capture (4C). This approach involves a circularization step that enables high-throughput screening of physical interactions between chromosomes without a preconceived idea of the interacting partners. Here we identify 114 unique sequences from all autosomes, several of which interact primarily with the maternally inherited H19 imprinting control region. Imprinted domains were strongly overrepresented in the library of 4C sequences, further highlighting the epigenetic nature of these interactions. Moreover, we found that the direct interaction between differentially methylated regions was linked to epigenetic regulation of transcription in trans. Finally, the patterns of interactions specific to the maternal H19 imprinting control region underwent reprogramming during in vitro maturation of embryonic stem cells. These observations shed new light on development, cancer epigenetics and the evolution of imprinting.
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