Heterochromatin

Heterochromatin is a tightly packed form of DNA or condensed DNA, which comes in multiple varieties. These varieties lie on a continuum between the two extremes of constitutive heterochromatin and facultative heterochromatin. Both play a role in the expression of genes. Because it is tightly packed, it was thought to be inaccessible to polymerases and therefore not transcribed; however, according to Volpe et al. (2002),[1] and many other papers since,[2] much of this DNA is in fact transcribed, but it is continuously turned over via RNA-induced transcriptional silencing (RITS). Recent studies with electron microscopy and OsO4 staining reveal that the dense packing is not due to the chromatin.[3]

Constitutive heterochromatin can affect the genes near itself (e.g. position-effect variegation). It is usually repetitive and forms structural functions such as centromeres or telomeres, in addition to acting as an attractor for other gene-expression or repression signals.

Facultative heterochromatin is the result of genes that are silenced through a mechanism such as histone deacetylation or Piwi-interacting RNA (piRNA) through RNAi. It is not repetitive and shares the compact structure of constitutive heterochromatin. However, under specific developmental or environmental signaling cues, it can lose its condensed structure and become transcriptionally active.[4]

Heterochromatin has been associated with the di- and tri -methylation of H3K9 in certain portions of the human genome.[5] H3K9me3-related methyltransferases appear to have a pivotal role in modifying heterochromatin during lineage commitment at the onset of organogenesis and in maintaining lineage fidelity.[6]

Structure

Heterochromatin vs. euchromatin

Chromatin is found in two varieties: euchromatin and heterochromatin.[7] Originally, the two forms were distinguished cytologically by how intensely they get stained – the euchromatin is less intense, while heterochromatin stains intensely, indicating tighter packing. Heterochromatin was given its name for this reason by botanist Emil Heitz who discovered that heterochromatin remained darkly stained throughout the entire cell cycle, unlike euchromatin whose stain disappeared during interphase.[8] Heterochromatin is usually localized to the periphery of the nucleus. Despite this early dichotomy, recent evidence in both animals[9] and plants[10] has suggested that there are more than two distinct heterochromatin states, and it may in fact exist in four or five 'states', each marked by different combinations of epigenetic marks.

Heterochromatin mainly consists of genetically inactive satellite sequences,[11] and many genes are repressed to various extents, although some cannot be expressed in euchromatin at all.[12] Both centromeres and telomeres are heterochromatic, as is the Barr body of the second, inactivated X-chromosome in a female.

Function

General model for duplication of heterochromatin during cell division
Microscopy of heterochromatic versus euchromatic nuclei (H&E stain).

Heterochromatin has been associated with several functions, from gene regulation to the protection of chromosome integrity;[13] some of these roles can be attributed to the dense packing of DNA, which makes it less accessible to protein factors that usually bind DNA or its associated factors. For example, naked double-stranded DNA ends would usually be interpreted by the cell as damaged or viral DNA, triggering cell cycle arrest, DNA repair or destruction of the fragment, such as by endonucleases in bacteria.

Some regions of chromatin are very densely packed with fibers that display a condition comparable to that of the chromosome at mitosis. Heterochromatin is generally clonally inherited; when a cell divides, the two daughter cells typically contain heterochromatin within the same regions of DNA, resulting in epigenetic inheritance. Variations cause heterochromatin to encroach on adjacent genes or recede from genes at the extremes of domains. Transcribable material may be repressed by being positioned (in cis) at these boundary domains. This gives rise to expression levels that vary from cell to cell,[14] which may be demonstrated by position-effect variegation.[15] Insulator sequences may act as a barrier in rare cases where constitutive heterochromatin and highly active genes are juxtaposed (e.g. the 5'HS4 insulator upstream of the chicken β-globin locus,[16] and loci in two Saccharomyces spp.[17][18]).

Constitutive heterochromatin

Main article: Constitutive heterochromatin

All cells of a given species package the same regions of DNA in constitutive heterochromatin, and thus in all cells, any genes contained within the constitutive heterochromatin will be poorly expressed. For example, all human chromosomes 1, 9, 16, and the Y-chromosome contain large regions of constitutive heterochromatin. In most organisms, constitutive heterochromatin occurs around the chromosome centromere and near telomeres.

Facultative heterochromatin

Schematic karyogram of a human, showing an overview of the human genome using G banding, which is a method that includes Giemsa staining, wherein the lighter staining regions are generally more euchromatic, whereas darker regions generally are more heterochromatic.
Further information: Karyotype

The regions of DNA packaged in facultative heterochromatin will not be consistent between the cell types within a species, and thus a sequence in one cell that is packaged in facultative heterochromatin (and the genes within are poorly expressed) may be packaged in euchromatin in another cell (and the genes within are no longer silenced). However, the formation of facultative heterochromatin is regulated, and is often associated with morphogenesis or differentiation. An example of facultative heterochromatin is X chromosome inactivation in female mammals: one X chromosome is packaged as facultative heterochromatin and silenced, while the other X chromosome is packaged as euchromatin and expressed.

Among the molecular components that appear to regulate the spreading of heterochromatin are the Polycomb-group proteins and non-coding genes such as Xist. The mechanism for such spreading is still a matter of controversy.[19] The polycomb repressive complexes PRC1 and PRC2 regulate chromatin compaction and gene expression and have a fundamental role in developmental processes. PRC-mediated epigenetic aberrations are linked to genome instability and malignancy and play a role in the DNA damage response, DNA repair and in the fidelity of replication.[20]

Yeast heterochromatin

Saccharomyces cerevisiae, or budding yeast, is a model eukaryote and its heterochromatin has been defined thoroughly. Although most of its genome can be characterized as euchromatin, S. cerevisiae has regions of DNA that are transcribed very poorly. These loci are the so-called silent mating type loci (HML and HMR), the rDNA (encoding ribosomal RNA), and the sub-telomeric regions. Fission yeast (Schizosaccharomyces pombe) uses another mechanism for heterochromatin formation at its centromeres. Gene silencing at this location depends on components of the RNAi pathway. Double-stranded RNA is believed to result in silencing of the region through a series of steps.

In the fission yeast Schizosaccharomyces pombe, two RNAi complexes, the RITS complex and the RNA-directed RNA polymerase complex (RDRC), are part of an RNAi machinery involved in the initiation, propagation and maintenance of heterochromatin assembly. These two complexes localize in a siRNA-dependent manner on chromosomes, at the site of heterochromatin assembly. RNA polymerase II synthesizes a transcript that serves as a platform to recruit RITS, RDRC and possibly other complexes required for heterochromatin assembly.[21][22] Both RNAi and an exosome-dependent RNA degradation process contribute to heterochromatic gene silencing. These mechanisms of Schizosaccharomyces pombe may occur in other eukaryotes.[23] A large RNA structure called RevCen has also been implicated in the production of siRNAs to mediate heterochromatin formation in some fission yeast.[24]

See also

References

  1. ^ Volpe TA, Kidner C, Hall IM, Teng G, Grewal SI, Martienssen RA (September 2002). "Regulation of heterochromatic silencing and histone H3 lysine-9 methylation by RNAi". Science. 297 (5588): 1833–7. Bibcode:2002Sci...297.1833V. doi:10.1126/science.1074973. PMID 12193640. S2CID 2613813.
  2. ^ "What is the current evidence showing active transcription withinin..." www.researchgate.net. Retrieved 2016-04-30.
  3. ^ Ou HD, Phan S, Deerinck TJ, Thor A, Ellisman MH, O'Shea CC (July 2017). "ChromEMT: Visualizing 3D chromatin structure and compaction in interphase and mitotic cells". Science. 357 (6349): eaag0025. doi:10.1126/science.aag0025. PMC 5646685. PMID 28751582.
  4. ^ Oberdoerffer P, Sinclair DA (September 2007). "The role of nuclear architecture in genomic instability and ageing". Nature Reviews. Molecular Cell Biology. 8 (9): 692–702. doi:10.1038/nrm2238. PMID 17700626. S2CID 15674132.
  5. ^ Rosenfeld JA, Wang Z, Schones DE, Zhao K, DeSalle R, Zhang MQ (March 2009). "Determination of enriched histone modifications in non-genic portions of the human genome". BMC Genomics. 10 (1): 143. doi:10.1186/1471-2164-10-143. PMC 2667539. PMID 19335899.
  6. ^ Nicetto D, Donahue G, Jain T, Peng T, Sidoli S, Sheng L, et al. (January 2019). "H3K9me3-heterochromatin loss at protein-coding genes enables developmental lineage specification". Science. 363 (6424): 294–297. Bibcode:2019Sci...363..294N. doi:10.1126/science.aau0583. PMC 6664818. PMID 30606806.
  7. ^ Elgin, S.C. (1996). "Heterochromatin and gene regulation in Drosophila". Current Opinion in Genetics & Development. 6 (2): 193–202. doi:10.1016/S0959-437X(96)80050-5. ISSN 0959-437X. PMID 8722176.
  8. ^ Penagos-Puig, Andrés; Furlan-Magaril, Mayra (2020-09-18). "Heterochromatin as an Important Driver of Genome Organization". Frontiers in Cell and Developmental Biology. 8. doi:10.3389/fcell.2020.579137. ISSN 2296-634X. PMC 7530337. PMID 33072761.
  9. ^ van Steensel B (May 2011). "Chromatin: constructing the big picture". The EMBO Journal. 30 (10): 1885–95. doi:10.1038/emboj.2011.135. PMC 3098493. PMID 21527910.
  10. ^ Roudier F, Ahmed I, Bérard C, Sarazin A, Mary-Huard T, Cortijo S, et al. (May 2011). "Integrative epigenomic mapping defines four main chromatin states in Arabidopsis". The EMBO Journal. 30 (10): 1928–38. doi:10.1038/emboj.2011.103. PMC 3098477. PMID 21487388.
  11. ^ Lohe AR, Hilliker AJ, Roberts PA (August 1993). "Mapping simple repeated DNA sequences in heterochromatin of Drosophila melanogaster". Genetics. 134 (4): 1149–74. doi:10.1093/genetics/134.4.1149. PMC 1205583. PMID 8375654.
  12. ^ Lu BY, Emtage PC, Duyf BJ, Hilliker AJ, Eissenberg JC (June 2000). "Heterochromatin protein 1 is required for the normal expression of two heterochromatin genes in Drosophila". Genetics. 155 (2): 699–708. doi:10.1093/genetics/155.2.699. PMC 1461102. PMID 10835392.
  13. ^ Grewal SI, Jia S (January 2007). "Heterochromatin revisited". Nature Reviews. Genetics. 8 (1): 35–46. doi:10.1038/nrg2008. PMID 17173056. S2CID 31811880. An up-to-date account of the current understanding of repetitive DNA, which usually doesn't contain genetic information. If evolution makes sense only in the context of the regulatory control of genes, we propose that heterochromatin, which is the main form of chromatin in higher eukaryotes, is positioned to be a deeply effective target for evolutionary change. Future investigations into assembly, maintenance and the many other functions of heterochromatin will shed light on the processes of gene and chromosome regulation.
  14. ^ Fisher AG, Merkenschlager M (April 2002). "Gene silencing, cell fate and nuclear organisation". Current Opinion in Genetics & Development. 12 (2): 193–7. doi:10.1016/S0959-437X(02)00286-1. PMID 11893493.
  15. ^ Zhimulev, I.F. [in Russian]; et al. (December 1986). "Cytogenetic and molecular aspects of position effect variegation in Drosophila melanogaster". Chromosoma. 94 (6): 492–504. doi:10.1007/BF00292759. ISSN 1432-0886. S2CID 24439936.
  16. ^ Burgess-Beusse B, Farrell C, Gaszner M, Litt M, Mutskov V, Recillas-Targa F, et al. (December 2002). "The insulation of genes from external enhancers and silencing chromatin". Proceedings of the National Academy of Sciences of the United States of America. 99 (Suppl 4): 16433–7. Bibcode:2002PNAS...9916433B. doi:10.1073/pnas.162342499. PMC 139905. PMID 12154228.
  17. ^ Allis CD, Grewal SI (August 2001). "Transitions in distinct histone H3 methylation patterns at the heterochromatin domain boundaries". Science. 293 (5532): 1150–5. doi:10.1126/science.1064150. PMID 11498594. S2CID 26350729.
  18. ^ Donze D, Kamakaka RT (February 2001). "RNA polymerase III and RNA polymerase II promoter complexes are heterochromatin barriers in Saccharomyces cerevisiae". The EMBO Journal. 20 (3): 520–31. doi:10.1093/emboj/20.3.520. PMC 133458. PMID 11157758.
  19. ^ Talbert PB, Henikoff S (October 2006). "Spreading of silent chromatin: inaction at a distance". Nature Reviews. Genetics. 7 (10): 793–803. doi:10.1038/nrg1920. PMID 16983375. S2CID 1671107.
  20. ^ Veneti Z, Gkouskou KK, Eliopoulos AG (July 2017). "Polycomb Repressor Complex 2 in Genomic Instability and Cancer". International Journal of Molecular Sciences. 18 (8): 1657. doi:10.3390/ijms18081657. PMC 5578047. PMID 28758948.
  21. ^ Kato H, Goto DB, Martienssen RA, Urano T, Furukawa K, Murakami Y (July 2005). "RNA polymerase II is required for RNAi-dependent heterochromatin assembly". Science. 309 (5733): 467–9. Bibcode:2005Sci...309..467K. doi:10.1126/science.1114955. PMID 15947136. S2CID 22636283.
  22. ^ Djupedal I, Portoso M, Spåhr H, Bonilla C, Gustafsson CM, Allshire RC, Ekwall K (October 2005). "RNA Pol II subunit Rpb7 promotes centromeric transcription and RNAi-directed chromatin silencing". Genes & Development. 19 (19): 2301–6. doi:10.1101/gad.344205. PMC 1240039. PMID 16204182.
  23. ^ Vavasseur; et al. (2008). "Heterochromatin Assembly and Transcriptional Gene Silencing under the Control of Nuclear RNAi: Lessons from Fission Yeast". RNA and the Regulation of Gene Expression: A Hidden Layer of Complexity. Caister Academic Press. ISBN 978-1-904455-25-7.
  24. ^ Djupedal I, Kos-Braun IC, Mosher RA, Söderholm N, Simmer F, Hardcastle TJ, et al. (December 2009). "Analysis of small RNA in fission yeast; centromeric siRNAs are potentially generated through a structured RNA". The EMBO Journal. 28 (24): 3832–44. doi:10.1038/emboj.2009.351. PMC 2797062. PMID 19942857.

Read other articles:

John Ashcroft

Halaman ini berisi artikel tentang Jaksa Agung Amerika Serikat masa lampau. Untuk Sekretaris Negara Bagian Missouri saat ini, lihat Jay Ashcroft. John Ashcroft Jaksa Agung Amerika Serikat ke-79Masa jabatan2 Februari 2001 – 3 Februari 2005PresidenGeorge W. BushWakilRobert Mueller (pelaksana tugas)Larry ThompsonJames Comey PendahuluJanet RenoPenggantiAlberto GonzalesSenator Amerika Serikat dari MissouriMasa jabatan3 Januari 1995 – 3 Januari 2001 PendahuluJohn DanforthPengg...

 

Indonesia's Next Top Model

Untuk siklus yang terakhir tayang, lihat Indonesia's Next Top Model (musim 3). Indonesia's Next Top ModelNama alternatifINTMGenre Acara realitas Acara bakat PembuatTyra BanksBerdasarkanAmerica's Next Top ModelPresenterLuna MayaJuri Luna Maya (2020-2023) Deddy Corbuzier (2020-2021) Patricia Gouw (2020-2021) Panca Makmun (2020-2023) Ivan Gunawan (2021-2023) Ayu Gani (2021-2023) Bahasa asli Bahasa Indonesia Bahasa Inggris Jmlh. musim3Jmlh. episode120ProduksiLokasi produksiSound Stage NET., G...

 

Keuskupan Samoa–Pago Pago

Keuskupan Samoa–Pago PagoDioecesis Samoa–PagopagensisKatolik LambangLokasiNegara Amerika SerikatWilayah Samoa AmerikaProvinsi gerejawiSamoa-ApiaStatistikLuas76 sq mi (200 km2)Populasi- Total- Katolik(per 2010)68.00014,000 (20.6%)Paroki16InformasiDenominasiGereja Katolik RomaRitusRitus RomaPendirian10 September 1982 (41 tahun lalu)KatedralKatedral Keluarga Kudus (Tafuna)KonkatedralKon-katedral Santo Yosef Tukang Kayu (Fagatogo)Kepemimpinan kiniP...

Élections législatives de 1988 dans le Calvados

1986 1993 Élections législatives de 1988 dans le Calvados 6 sièges de députés à l'Assemblée nationale 5 et 12 juin 1988 Corps électoral et résultats Inscrits au 1er tour 419 437 Votants au 1er tour 269 319   64,21 %  13,4 Votes exprimés au 1er tour 264 288 Inscrits au 2d tour 285 951 Votants au 2d tour 203 007   70,99 % Votes exprimés au 2d tour 198 531 Union du Rassemblement et du Centre Liste Rassemblement pour la R...

 

Bendera Turki

Rasio bendera: 2:3 Bendera Turki terdiri dari sebuah bulan sabit berwarna putih dan bintang putih pada sebuah latar belakang berwarna merah. Bendera ini disebut Ay Yıldız dalam bahasa Turki yang artinya adalah bulan bintang. Lihat pula Bendera Kesultanan Utsmaniyah Lambang Turki Artikel bertopik bendera ini adalah sebuah rintisan. Anda dapat membantu Wikipedia dengan mengembangkannya.lbs lbsBendera di duniaBendera negara berdaulat · Daerah dependensiAfrika Afrika Selatan Afrika Tengah...

 

Biara Wiblingen

Biara WiblingenKloster WiblingenBiara WiblingenInformasi biaraOrdoBenediktinDidirikan1093Dibubarkan1806TokohPendiriHartmann von Kirchberg, Otto von Kirchberg, adipati KirchbergArsitekturArsitekChristian WiedemannModelBarokSitusAkses publikyes Pemandangan udara Biara Wiblingen Gerbang biara Gereja biara dengan menara yang belum selesai dan sayap selatan biara Interior gereja biara Panti imam karya Fidel Sporer Interior perpustakaan Salah satu lemari buku di perpustakaan biara Biara Wiblingen (...

ZooBank

International web registry for animal names The taxon treatment for the frog Paedophryne amauensis,[1] mentioning the LSID for this nomenclatural act.[2] ZooBank is an open access website intended to be the official International Commission on Zoological Nomenclature (ICZN) registry of zoological nomenclature.[3] Any nomenclatural acts (e.g. publications that create or change a taxonomic name) published electronically need to be registered with ZooBank prior to publica...

 

International Tennis Championships 1997

International Tennis Championships 1997 Sport Tennis Data 5 maggio – 12 maggio Edizione 5a Superficie Terra rossa Campioni Singolare Jason Stoltenberg Doppio Dave Randall / Greg Van Emburgh 1996 1998 L'International Tennis Championships 1997 è stato un torneo di tennis giocato su Terra Har-Tru. È stata la 5ª edizione dell'International Tennis Championships, che fa parte della categoria ATP World Series nell'ambito dell'ATP Tour 1997. Si è giocato a Coral Springs in Florida, dal 5 maggi...

 

São Gonçalo do Sapucaí

Questa voce sull'argomento centri abitati del Minas Gerais è solo un abbozzo. Contribuisci a migliorarla secondo le convenzioni di Wikipedia. Segui i suggerimenti del progetto di riferimento. São Gonçalo do Sapucaícomune São Gonçalo do Sapucaí – Veduta LocalizzazioneStato Brasile Stato federato Minas Gerais MesoregioneSul e Sudoeste de Minas MicroregioneSanta Rita do Sapucaí AmministrazioneSindacoBenedito Álvaro Cunha TerritorioCoordinate21°53′33″S 45°35′44�...

Cadole

Cadole en pierre sèche à Lugny, en Haut-Mâconnais (photo prise en 2004). « Cadole » est le nom donné aux anciennes cabanes, souvent en pierres sèches, des vignobles de l'Aube et de Bourgogne du Sud, et plus particulièrement du Beaujolais. Variantes du mot Le terme cadole, issu du patois lyonnais[1], s'écrit aussi cadolle. On trouve également la variante cadeule, ainsi à Martailly-lès-Brancion (Saône-et-Loire)[2]. Aire d'extension du mot Pris dans le sens de « caba...

 

The Only Living Boy in New York

The Only Living Boy in New YorkThomas in una scena del filmLingua originaleinglese Paese di produzioneStati Uniti d'America Anno2017 Generedrammatico RegiaMarc Webb SceneggiaturaAllan Loeb ProduttoreAlbert Berger, Ron Yerxa Produttore esecutivoMolly Allen, Glen Basner, Ben Browning Casa di produzioneAmazon StudiosBig Indie PicturesBona Fide Productions FotografiaStuart Dryburgh MontaggioTim Streeto MusicheRob Simonsen ScenografiaLaura Fox Interpreti e personaggi Callum Turner: Thomas Webb Jef...

 

ヨハネス12世 (ローマ教皇)

ヨハネス12世 第130代 ローマ教皇 教皇就任 955年12月16日教皇離任 964年5月14日先代 アガペトゥス2世次代 レオ8世個人情報出生 937年スポレート公国（中部イタリア）スポレート死去 964年5月14日 教皇領、ローマ原国籍 スポレート公国親 父アルベリーコ2世（スポレート公）、母アルダその他のヨハネステンプレートを表示 ヨハネス12世（Ioannes XII、937年 - 964年5月14日）は、ロ...

1426 هـ

1426 هـمعلومات عامةجزء من تقويم هجري تاريخ البدء 10 فبراير 2005[1] تاريخ الانتهاء 30 يناير 2006[1]31 يناير 2006 تصنيف مواليد هذا الزمن تصنيف وفيات هذا الزمن لديه جزء أو أجزاء محرم 1426 هـصفر 1426 هـربيع الأول 1426 هـ 1425 هـ 1427 هـ تعديل - تعديل مصدري - تعديل ويكي بيانات قرن: قرن 14 - قرن 15 - ق�...

 

Panpsychism

View that mind is a fundamental feature of reality Not to be confused with Hylozoism. Illustration of the Neoplatonic concept of the anima mundi emanating from The Absolute, in some ways a precursor to modern panpsychism In the philosophy of mind, panpsychism (/pænˈsaɪkɪzəm/) is the view that the mind or a mind-like aspect is a fundamental and ubiquitous feature of reality.[1] It is also described as a theory that the mind is a fundamental feature of the world which exists throug...

 

Presidents Race

Promotional event Tom, George, Teddy, and Abe, a few days after their live debut at RFK Stadium in 2006. The Presidents Race is a promotional event that has been run at every Washington Nationals home game since July 21, 2006. It is held in the middle of the fourth inning of every game. The Presidents Race has featured likenesses of seven former Presidents of the United States, four of whom are found on Mount Rushmore: George Washington, Abraham Lincoln, Thomas Jefferson, and Theodore Rooseve...

Okoba Station

Railway station in Hitoyoshi, Kumamoto Prefecture, Japan This article does not cite any sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: Okoba Station – news · newspapers · books · scholar · JSTOR (March 2018) (Learn how and when to remove this message) Okoba Station大畑駅Okoba Station in March 2017General informationLocationOkobafumoto-machi, HitoyoshiK...

 

2013 Italian Grand Prix

2013 Italian Grand Prix Race 12 of 19 in the 2013 Formula One World Championship← Previous raceNext race → Autodromo Nazionale di MonzaRace detailsDate 8 September 2013Official name 2013 Formula 1 Gran Premio d'Italia[1]Location Autodromo Nazionale di MonzaMonza, ItalyCourse Permanent racing facilityCourse length 5.793 km (3.600 miles)Distance 53 laps, 307.029 km (190.580 miles)Weather CloudyPole positionDriver Sebastian Vettel Red Bull-RenaultTime 1:23.755Fas...

 

2023 Utah State Aggies football team

American college football season This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: 2023 Utah State Aggies football team – news · newspapers · books · scholar · JSTOR (April 2023) (Learn how and when to remove this message) 2023 Utah State Aggies footballFamous Idaho Potato Bowl, L 22–45 vs. Georgia StateConf...

Bloody Sunday (1972)

Bloody SundaystrageTipoSpari sulla folla Data30 gennaio 1972 LuogoDerry Stato Irlanda del Nord Coordinate54°59′49.08″N 7°19′32.01″W54°59′49.08″N, 7°19′32.01″W Responsabili1º battaglione del Reggimento Paracadutisti dell'Esercito Britannico MotivazioneRepressione politica ConseguenzeMorti14 Feriti15 Modifica dati su Wikidata · Manuale La strage del Bogside, popolarmente nota come Bloody Sunday (Domenica di sangue o Domenica maledetta),[1][2] è a...

 

Jeu vidéo de course

Si ce bandeau n'est plus pertinent, retirez-le. Cliquez ici pour en savoir plus. Cet article ne cite pas suffisamment ses sources (octobre 2010). Si vous disposez d'ouvrages ou d'articles de référence ou si vous connaissez des sites web de qualité traitant du thème abordé ici, merci de compléter l'article en donnant les références utiles à sa vérifiabilité et en les liant à la section « Notes et références ». En pratique : Quelles sources sont attendues ? C...