fbpx
Wikipedia

Insulator (genetics)

January 01, 1970

For electrical insulator, see Insulator (electricity).
For other uses, see Insulation (disambiguation).

An insulator is a type of cis-regulatory element known as a long-range regulatory element. Found in multicellular eukaryotes and working over distances from the promoter element of the target gene, an insulator is typically 300 bp to 2000 bp in length.[1] Insulators contain clustered binding sites for sequence specific DNA-binding proteins[1] and mediate intra- and inter-chromosomal interactions.[2]

Insulators function either as an enhancer-blocker or a barrier, or both. The mechanisms by which an insulator performs these two functions include loop formation and nucleosome modifications.[3][4] There are many examples of insulators, including the CTCF insulator, the gypsy insulator, and the β-globin locus. The CTCF insulator is especially important in vertebrates, while the gypsy insulator is implicated in Drosophila. The β-globin locus was first studied in chicken and then in humans for its insulator activity, both of which utilize CTCF.[5]

The genetic implications of insulators lie in their involvement in a mechanism of imprinting and their ability to regulate transcription. Mutations to insulators are linked to cancer as a result of cell cycle disregulation, tumourigenesis, and silencing of growth suppressors.

Function edit

Insulators have two main functions:[3][4]

  1. Enhancer-blocking insulators prevent distal enhancers from acting on the promoter of neighbouring genes
  2. Barrier insulators prevent silencing of euchromatin by the spread of neighbouring heterochromatin

While enhancer-blocking is classified as an inter-chromosomal interaction, acting as a barrier is classified as an intra-chromosomal interaction. The need for insulators arises where two adjacent genes on a chromosome have very different transcription patterns; it is critical that the inducing or repressing mechanisms of one do not interfere with the neighbouring gene.[6] Insulators have also been found to cluster at the boundaries of topologically associating domains (TADs) and may have a role in partitioning the genome into "chromosome neighborhoods" - genomic regions within which regulation occurs.[7][8]

Some insulators can act as both enhancer blocker and barriers, and some just have one of the two functions.[3] Some examples of different insulators are:[3]

  • Drosophila melanogaster insulators gypsy and scs scs are both enhancer-blocking insulators
  • Gallus gallus have insulators, Lys 5' A that have both enhancer-blocking and barrier activity, as well as HS4 that have only enhancer-blocking activity
  • Saccharomyces cerevisiae insulators STAR and UASrpg are both barrier insulators
  • Homo sapiens HS5 insulator acts as an enhancer-blocker

Mechanism of action edit

Enhancer-blocking insulators edit

 

Similar mechanism of action for enhancer-blocking insulators; chromatin loop domains are formed in the nucleus that separates the enhancer and the promoter of a target gene. Loop domains are formed through the interaction between enhancer-blocking elements interacting with each other or securing chromatin fibre to structural elements within the nucleus.[4] The action of these insulators is dependent on being positioned between the promoter of the target gene and the upstream or down stream enhancer. The specific way in which insulators block enhancers is dependent on the enhancers mode of action. Enhancers can directly interact with their target promoters through looping[9] (direct-contact model), in which case an insulator prevents this interaction through the formation of a loop domain that separates the enhancer and promoter sites and prevents the promoter-enhancer loop from forming.[4] An enhancer can also act on a promoter through a signal (tracking model of enhancer action). This signal may be blocked by an insulator through the targeting of a nucleoprotein complex at the base of the loop formation.[4]

Barrier insulators edit

Barrier activity has been linked to the disruption of specific processes in the heterochromatin formation pathway. These types of insulators modify the nucleosomal substrate in the reaction cycle that is central to heterochromatin formation.[4] Modifications are achieved through various mechanisms including nucleosome removal, in which nucleosome-excluding elements disrupt heterochromatin from spreading and silencing (chromatin-mediated silencing). Modification can also be done through recruitment of histone acetyltransferase(s) and ATP-dependent nucleosome remodelling complexes.[4]

CTCF insulator edit

The CTCF insulator appears to have enhancer blocking activity via its 3D structure[10] and have no direct connection with barrier activity.[11] Vertebrates in particular appear to rely heavily on the CTCF insulator, however there are many different insulator sequences identified.[2] Insulated neighborhoods formed by physical interaction between two CTCF-bound DNA loci contain the interactions between enhancers and their target genes.[12]

Regulation edit

One mechanism of regulating CTCF is via methylation of its DNA sequence. CTCF protein is known to favourably bind to unmethylated sites, so it follows that methylation of CpG islands is a point of epigenetic regulation.[2] An example of this is seen in the Igf2-H19 imprinted locus where methylation of the paternal imprinted control region (ICR) prevents CTCF from binding.[13] A second mechanism of regulation is through regulating proteins that are required for fully functioning CTCF insulators. These proteins include, but are not limited to cohesin, RNA polymerase, and CP190.[2][14]

gypsy insulator edit

The insulator element that is found in the gypsy retrotransposon of Drosophila is one of several sequences that have been studied in detail. The gypsy insulator can be found in the 5' untranslated region (UTR) of the retrotransposon element. Gypsy affects the expression of adjacent genes pending insertion into a new genomic location, causing mutant phenotypes that are both tissue specific and present at certain developmental stages. The insulator likely has an inhibitory effect on enhancers that control the spatial and temporal expression of the affected gene.[15]

β-globin locus edit

The first examples of insulators in vertebrates was seen in the chicken β-globin locus, cHS4. cHS4 marks the border between the active euchromatin in the β-globin locus and the upstream heterochromatin region that is highly condensed and inactive. The cHS4 insulator acts as both a barrier to chromatin-mediated silencing via heterochromatin spreading, and blocks interactions between enhancers and promoters. A distinguishing characteristic of cHS4 is that it has a repetitive heterochromatic region on its 5' end.[5]

The human β-globin locus homologue of cHS4 is HS5. Different from the chicken β-globin locus, the human β-globin locus has an open chromatin structure and is not flanked by a 5' heterochromatic region. HS5 is thought to be a genetic insulator in vivo as it has both enhancer-blocking activity and transgene barrier activities.[5]

CTCF was first characterized for its role in regulating β-globin gene expression. At this locus, CTCF functions as an insulator-binding protein forming a chromosomal boundary.[13] CTCF is present in both the chicken β-globin locus and human β-globin locus. Within cHS4 of the chicken β-globin locus, CTCF binds to a region (FII) that is responsible for enhancer blocking activity.[5]

Genetic implications edit

Imprinting edit

The ability of enhancers to activate imprinted genes is dependent on the presence of an insulator on the unmethylated allele between the two genes. An example of this is the Igf2-H19 imprinted locus. In this locus the CTCF protein regulates imprinted expression by binding to the unmethylated maternal imprinted control region (ICR) but not on the paternal ICR. When bound to the unmethylated maternal sequence, CTCF effectively blocks downstream enhancer elements from interacting with the Igf2 gene promoter, leaving only the H19 gene to be expressed.[13]

Transcription edit

When insulator sequences are located in close proximity to the promoter of a gene, it has been suggested that they might serve to stabilize enhancer-promoter interactions. When they are located farther away from the promoter, insulator elements would compete with the enhancer and interfere with activation of transcription.[3] Loop formation is common in eukaryotes to bring distal elements (enhancers, promoters, locus control regions) into closer proximity for interaction during transcription.[4] The mechanism of enhancer-blocking insulators then, if in the correct position, could play a role in regulating transcription activation.[3]

Mutations and cancer edit

CTCF insulators affect the expression of genes implicated in cell cycle regulation processes that are important for cell growth, cell differentiation, and programmed cell death (apoptosis). Two of these cell cycle regulation genes that are known to interact with CTCF are hTERT and C-MYC. In these cases, a loss of function mutation to the CTCF insulator gene changes the expression patterns and may affect the interplay between cell growth, differentiation and apoptosis and lead to tumourigenesis or other problems.[2]

CTCF is also required for the expression of tumour repressor retinoblastoma (Rb) gene and mutations and deletions of this gene are associated with inherited malignancies. When the CTCF binding site is removed expression of Rb is decreased and tumours are able to thrive.[2]

Other genes that encode cell cycle regulators include BRCA1, and p53, which are growth suppressors that are silenced in many cancer types, and whose expression is controlled by CTCF. Loss of function of CTCF in these genes leads to the silencing of the growth suppressor and contributes to the formation of cancer.[2]

The aberrant activation of insulators can modulate the expression of cancer-related genes, including matrix metalloproteinases involved in cancer cell invasion.[16]

References edit

  1. ^ a b Allison, Lizabeth A. (2012). Fundamental Molecular Biology. New Jersey: John Wiley & Sons, Inc. pp. 300–301. ISBN 9781118059814.
  2. ^ a b c d e f g Yang, Jingping; Corces, Victor G. (2011). "Chromatin Insulators: A Role in Nuclear Organization and Gene Expression". Advances in Cancer Research. 110: 43–76. doi:10.1016/B978-0-12-386469-7.00003-7. ISBN 9780123864697. ISSN 0065-230X. PMC 3175007. PMID 21704228.
  3. ^ a b c d e f West, Adam G.; Gaszner, Miklos; Felsenfeld, Gary (2002-02-01). "Insulators: many functions, many mechanisms". Genes & Development. 16 (3): 271–288. doi:10.1101/gad.954702. ISSN 0890-9369. PMID 11825869.
  4. ^ a b c d e f g h Gaszner, Miklos; Felsenfeld, Gary (September 2006). "Insulators: exploiting transcriptional and epigenetic mechanisms". Nature Reviews Genetics. 7 (9): 703–713. doi:10.1038/nrg1925. ISSN 1471-0064. PMID 16909129. S2CID 31291034.
  5. ^ a b c d Wai, Albert W.K.; Gillemans, Nynke; Raguz-Bolognesi, Selina; Pruzina, Sara; Zafarana, Gaetano; Meijer, Dies; Philipsen, Sjaak; Grosveld, Frank (2003-09-01). "HS5 of the human β-globin locus control region: a developmental stage-specific border in erythroid cells". The EMBO Journal. 22 (17): 4489–4500. doi:10.1093/emboj/cdg437. ISSN 0261-4189. PMC 202379. PMID 12941700.
  6. ^ Burgess-Beusse B, Farrell C, Gaszner M, Litt M, Mutskov V, Recillas-Targa F, Simpson M, West A, Felsenfeld G (December 2002). "The insulation of genes from external enhancers and silencing chromatin". Proc. Natl. Acad. Sci. U.S.A. 99 (Suppl 4): 16433–7. Bibcode:2002PNAS...9916433B. doi:10.1073/pnas.162342499. PMC 139905. PMID 12154228.
  7. ^ Perkel J (1 June 2015). "Mapping chromosome neighborhoods". BioTechniques. 58 (6): 280–284. doi:10.2144/000114296. PMID 26054763.
  8. ^ Ong CT; Corces VG (April 2014). "CTCF: an architectural protein bridging genome topology and function". Nat Rev Genet. 15 (4): 234–46. doi:10.1038/nrg3663. PMC 4610363. PMID 24614316.
  9. ^ Deng, W; Lee, J; Wang, H; Miller, J; Reik, A; Gregory, P. D.; Dean, A; Blobel, G. A. (2012). "Controlling long-range genomic interactions at a native locus by targeted tethering of a looping factor". Cell. 149 (6): 1233–44. doi:10.1016/j.cell.2012.03.051. PMC 3372860. PMID 22682246.
  10. ^ Phillips JE, Corces VG (June 2009). "CTCF: master weaver of the genome". Cell. 137 (7): 1194–211. doi:10.1016/j.cell.2009.06.001. PMC 3040116. PMID 19563753.
  11. ^ Phillips, Jennifer E.; Corces, Victor G. (2009-06-26). "CTCF: Master Weaver of the Genome". Cell. 137 (7): 1194–1211. doi:10.1016/j.cell.2009.06.001. ISSN 0092-8674. PMC 3040116. PMID 19563753.
  12. ^ Dowen, JM; Fan, ZP; Hnisz, D; Ren, G; Abraham, BJ; Zhang, LN; Weintraub, AS; Schuijers, J; Lee, TI; Zhao, K; Young, RA (9 October 2014). "Control of cell identity genes occurs in insulated neighborhoods in mammalian chromosomes". Cell. 159 (2): 374–87. doi:10.1016/j.cell.2014.09.030. PMC 4197132. PMID 25303531.
  13. ^ a b c Allison, Lizabeth A. (2012). Fundamental Molecular Biology. New Jersey: John Wiley & Sons, Inc. p. 367. ISBN 9781118059814.
  14. ^ Kim, Somi; Yu, Nam-Kyung; Kaang, Bong-Kiun (June 2015). "CTCF as a multifunctional protein in genome regulation and gene expression". Experimental & Molecular Medicine. 47 (6): e166. doi:10.1038/emm.2015.33. ISSN 2092-6413. PMC 4491725. PMID 26045254.
  15. ^ Gdula, David A.; Gerasimova, Tatiana I.; Corces, Victor G. (1996). "Genetic and Molecular Analysis of the gypsy Chromatin Insulator of Drosophila". Proceedings of the National Academy of Sciences of the United States of America. 93 (18): 9378–9383. Bibcode:1996PNAS...93.9378G. doi:10.1073/pnas.93.18.9378. JSTOR 39717. PMC 38435. PMID 8790337.
  16. ^ Llinàs-Arias P, Ensenyat-Mendez M, Íñiguez-Muñoz S, Orozco J, Valdez B (November 2023). "Chromatin insulation orchestrates matrix metalloproteinase gene cluster expression reprogramming in aggressive breast cancer tumors". Molecular Cancer. 22 (4): 190. doi:10.1186/s12943-023-01906-8. PMC 10683115. PMID 38017545.

External links edit

  •   Media related to Insulator (genetics) at Wikimedia Commons

January 01, 1970
insulator, genetics, electrical, insulator, insulator, electricity, other, uses, insulation, disambiguation, insulator, type, regulatory, element, known, long, range, regulatory, element, found, multicellular, eukaryotes, working, over, distances, from, promot. For electrical insulator see Insulator electricity For other uses see Insulation disambiguation An insulator is a type of cis regulatory element known as a long range regulatory element Found in multicellular eukaryotes and working over distances from the promoter element of the target gene an insulator is typically 300 bp to 2000 bp in length 1 Insulators contain clustered binding sites for sequence specific DNA binding proteins 1 and mediate intra and inter chromosomal interactions 2 Insulators function either as an enhancer blocker or a barrier or both The mechanisms by which an insulator performs these two functions include loop formation and nucleosome modifications 3 4 There are many examples of insulators including the CTCF insulator the gypsy insulator and the b globin locus The CTCF insulator is especially important in vertebrates while the gypsy insulator is implicated in Drosophila The b globin locus was first studied in chicken and then in humans for its insulator activity both of which utilize CTCF 5 The genetic implications of insulators lie in their involvement in a mechanism of imprinting and their ability to regulate transcription Mutations to insulators are linked to cancer as a result of cell cycle disregulation tumourigenesis and silencing of growth suppressors Contents 1 Function 2 Mechanism of action 2 1 Enhancer blocking insulators 2 2 Barrier insulators 3 CTCF insulator 3 1 Regulation 4 gypsy insulator 5 b globin locus 6 Genetic implications 6 1 Imprinting 6 2 Transcription 7 Mutations and cancer 8 References 9 External linksFunction editInsulators have two main functions 3 4 Enhancer blocking insulators prevent distal enhancers from acting on the promoter of neighbouring genes Barrier insulators prevent silencing of euchromatin by the spread of neighbouring heterochromatin While enhancer blocking is classified as an inter chromosomal interaction acting as a barrier is classified as an intra chromosomal interaction The need for insulators arises where two adjacent genes on a chromosome have very different transcription patterns it is critical that the inducing or repressing mechanisms of one do not interfere with the neighbouring gene 6 Insulators have also been found to cluster at the boundaries of topologically associating domains TADs and may have a role in partitioning the genome into chromosome neighborhoods genomic regions within which regulation occurs 7 8 Some insulators can act as both enhancer blocker and barriers and some just have one of the two functions 3 Some examples of different insulators are 3 Drosophila melanogaster insulators gypsy and scs scs are both enhancer blocking insulators Gallus gallus have insulators Lys 5 A that have both enhancer blocking and barrier activity as well as HS4 that have only enhancer blocking activity Saccharomyces cerevisiae insulators STAR and UASrpg are both barrier insulators Homo sapiens HS5 insulator acts as an enhancer blockerMechanism of action editEnhancer blocking insulators edit nbsp Similar mechanism of action for enhancer blocking insulators chromatin loop domains are formed in the nucleus that separates the enhancer and the promoter of a target gene Loop domains are formed through the interaction between enhancer blocking elements interacting with each other or securing chromatin fibre to structural elements within the nucleus 4 The action of these insulators is dependent on being positioned between the promoter of the target gene and the upstream or down stream enhancer The specific way in which insulators block enhancers is dependent on the enhancers mode of action Enhancers can directly interact with their target promoters through looping 9 direct contact model in which case an insulator prevents this interaction through the formation of a loop domain that separates the enhancer and promoter sites and prevents the promoter enhancer loop from forming 4 An enhancer can also act on a promoter through a signal tracking model of enhancer action This signal may be blocked by an insulator through the targeting of a nucleoprotein complex at the base of the loop formation 4 Barrier insulators edit Barrier activity has been linked to the disruption of specific processes in the heterochromatin formation pathway These types of insulators modify the nucleosomal substrate in the reaction cycle that is central to heterochromatin formation 4 Modifications are achieved through various mechanisms including nucleosome removal in which nucleosome excluding elements disrupt heterochromatin from spreading and silencing chromatin mediated silencing Modification can also be done through recruitment of histone acetyltransferase s and ATP dependent nucleosome remodelling complexes 4 CTCF insulator editThe CTCF insulator appears to have enhancer blocking activity via its 3D structure 10 and have no direct connection with barrier activity 11 Vertebrates in particular appear to rely heavily on the CTCF insulator however there are many different insulator sequences identified 2 Insulated neighborhoods formed by physical interaction between two CTCF bound DNA loci contain the interactions between enhancers and their target genes 12 Regulation edit One mechanism of regulating CTCF is via methylation of its DNA sequence CTCF protein is known to favourably bind to unmethylated sites so it follows that methylation of CpG islands is a point of epigenetic regulation 2 An example of this is seen in the Igf2 H19 imprinted locus where methylation of the paternal imprinted control region ICR prevents CTCF from binding 13 A second mechanism of regulation is through regulating proteins that are required for fully functioning CTCF insulators These proteins include but are not limited to cohesin RNA polymerase and CP190 2 14 gypsy insulator editThe insulator element that is found in the gypsy retrotransposon of Drosophila is one of several sequences that have been studied in detail The gypsy insulator can be found in the 5 untranslated region UTR of the retrotransposon element Gypsy affects the expression of adjacent genes pending insertion into a new genomic location causing mutant phenotypes that are both tissue specific and present at certain developmental stages The insulator likely has an inhibitory effect on enhancers that control the spatial and temporal expression of the affected gene 15 b globin locus editThe first examples of insulators in vertebrates was seen in the chicken b globin locus cHS4 cHS4 marks the border between the active euchromatin in the b globin locus and the upstream heterochromatin region that is highly condensed and inactive The cHS4 insulator acts as both a barrier to chromatin mediated silencing via heterochromatin spreading and blocks interactions between enhancers and promoters A distinguishing characteristic of cHS4 is that it has a repetitive heterochromatic region on its 5 end 5 The human b globin locus homologue of cHS4 is HS5 Different from the chicken b globin locus the human b globin locus has an open chromatin structure and is not flanked by a 5 heterochromatic region HS5 is thought to be a genetic insulator in vivo as it has both enhancer blocking activity and transgene barrier activities 5 CTCF was first characterized for its role in regulating b globin gene expression At this locus CTCF functions as an insulator binding protein forming a chromosomal boundary 13 CTCF is present in both the chicken b globin locus and human b globin locus Within cHS4 of the chicken b globin locus CTCF binds to a region FII that is responsible for enhancer blocking activity 5 Genetic implications editImprinting edit The ability of enhancers to activate imprinted genes is dependent on the presence of an insulator on the unmethylated allele between the two genes An example of this is the Igf2 H19 imprinted locus In this locus the CTCF protein regulates imprinted expression by binding to the unmethylated maternal imprinted control region ICR but not on the paternal ICR When bound to the unmethylated maternal sequence CTCF effectively blocks downstream enhancer elements from interacting with the Igf2 gene promoter leaving only the H19 gene to be expressed 13 Transcription edit When insulator sequences are located in close proximity to the promoter of a gene it has been suggested that they might serve to stabilize enhancer promoter interactions When they are located farther away from the promoter insulator elements would compete with the enhancer and interfere with activation of transcription 3 Loop formation is common in eukaryotes to bring distal elements enhancers promoters locus control regions into closer proximity for interaction during transcription 4 The mechanism of enhancer blocking insulators then if in the correct position could play a role in regulating transcription activation 3 Mutations and cancer editCTCF insulators affect the expression of genes implicated in cell cycle regulation processes that are important for cell growth cell differentiation and programmed cell death apoptosis Two of these cell cycle regulation genes that are known to interact with CTCF are hTERT and C MYC In these cases a loss of function mutation to the CTCF insulator gene changes the expression patterns and may affect the interplay between cell growth differentiation and apoptosis and lead to tumourigenesis or other problems 2 CTCF is also required for the expression of tumour repressor retinoblastoma Rb gene and mutations and deletions of this gene are associated with inherited malignancies When the CTCF binding site is removed expression of Rb is decreased and tumours are able to thrive 2 Other genes that encode cell cycle regulators include BRCA1 and p53 which are growth suppressors that are silenced in many cancer types and whose expression is controlled by CTCF Loss of function of CTCF in these genes leads to the silencing of the growth suppressor and contributes to the formation of cancer 2 The aberrant activation of insulators can modulate the expression of cancer related genes including matrix metalloproteinases involved in cancer cell invasion 16 References edit a b Allison Lizabeth A 2012 Fundamental Molecular Biology New Jersey John Wiley amp Sons Inc pp 300 301 ISBN 9781118059814 a b c d e f g Yang Jingping Corces Victor G 2011 Chromatin Insulators A Role in Nuclear Organization and Gene Expression Advances in Cancer Research 110 43 76 doi 10 1016 B978 0 12 386469 7 00003 7 ISBN 9780123864697 ISSN 0065 230X PMC 3175007 PMID 21704228 a b c d e f West Adam G Gaszner Miklos Felsenfeld Gary 2002 02 01 Insulators many functions many mechanisms Genes amp Development 16 3 271 288 doi 10 1101 gad 954702 ISSN 0890 9369 PMID 11825869 a b c d e f g h Gaszner Miklos Felsenfeld Gary September 2006 Insulators exploiting transcriptional and epigenetic mechanisms Nature Reviews Genetics 7 9 703 713 doi 10 1038 nrg1925 ISSN 1471 0064 PMID 16909129 S2CID 31291034 a b c d Wai Albert W K Gillemans Nynke Raguz Bolognesi Selina Pruzina Sara Zafarana Gaetano Meijer Dies Philipsen Sjaak Grosveld Frank 2003 09 01 HS5 of the human b globin locus control region a developmental stage specific border in erythroid cells The EMBO Journal 22 17 4489 4500 doi 10 1093 emboj cdg437 ISSN 0261 4189 PMC 202379 PMID 12941700 Burgess Beusse B Farrell C Gaszner M Litt M Mutskov V Recillas Targa F Simpson M West A Felsenfeld G December 2002 The insulation of genes from external enhancers and silencing chromatin Proc Natl Acad Sci U S A 99 Suppl 4 16433 7 Bibcode 2002PNAS 9916433B doi 10 1073 pnas 162342499 PMC 139905 PMID 12154228 Perkel J 1 June 2015 Mapping chromosome neighborhoods BioTechniques 58 6 280 284 doi 10 2144 000114296 PMID 26054763 Ong CT Corces VG April 2014 CTCF an architectural protein bridging genome topology and function Nat Rev Genet 15 4 234 46 doi 10 1038 nrg3663 PMC 4610363 PMID 24614316 Deng W Lee J Wang H Miller J Reik A Gregory P D Dean A Blobel G A 2012 Controlling long range genomic interactions at a native locus by targeted tethering of a looping factor Cell 149 6 1233 44 doi 10 1016 j cell 2012 03 051 PMC 3372860 PMID 22682246 Phillips JE Corces VG June 2009 CTCF master weaver of the genome Cell 137 7 1194 211 doi 10 1016 j cell 2009 06 001 PMC 3040116 PMID 19563753 Phillips Jennifer E Corces Victor G 2009 06 26 CTCF Master Weaver of the Genome Cell 137 7 1194 1211 doi 10 1016 j cell 2009 06 001 ISSN 0092 8674 PMC 3040116 PMID 19563753 Dowen JM Fan ZP Hnisz D Ren G Abraham BJ Zhang LN Weintraub AS Schuijers J Lee TI Zhao K Young RA 9 October 2014 Control of cell identity genes occurs in insulated neighborhoods in mammalian chromosomes Cell 159 2 374 87 doi 10 1016 j cell 2014 09 030 PMC 4197132 PMID 25303531 a b c Allison Lizabeth A 2012 Fundamental Molecular Biology New Jersey John Wiley amp Sons Inc p 367 ISBN 9781118059814 Kim Somi Yu Nam Kyung Kaang Bong Kiun June 2015 CTCF as a multifunctional protein in genome regulation and gene expression Experimental amp Molecular Medicine 47 6 e166 doi 10 1038 emm 2015 33 ISSN 2092 6413 PMC 4491725 PMID 26045254 Gdula David A Gerasimova Tatiana I Corces Victor G 1996 Genetic and Molecular Analysis of the gypsy Chromatin Insulator of Drosophila Proceedings of the National Academy of Sciences of the United States of America 93 18 9378 9383 Bibcode 1996PNAS 93 9378G doi 10 1073 pnas 93 18 9378 JSTOR 39717 PMC 38435 PMID 8790337 Llinas Arias P Ensenyat Mendez M Iniguez Munoz S Orozco J Valdez B November 2023 Chromatin insulation orchestrates matrix metalloproteinase gene cluster expression reprogramming in aggressive breast cancer tumors Molecular Cancer 22 4 190 doi 10 1186 s12943 023 01906 8 PMC 10683115 PMID 38017545 External links edit nbsp Media related to Insulator genetics at Wikimedia Commons Retrieved from https en wikipedia org w index php title Insulator genetics amp oldid 1189919591, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.