title: The topography of chromosomes and genes in the nucleus.
abstract: At present several lines of evidence indicate that the nucleus is functionally compartmentalized into discrete structures with defined properties. For instance, it is well established that the molecular machines involved in replication, transcription, and RNA processing assemble into morphological entities but it remains unclear whether these correspond to autonomous "organelles" or rather represent temporary accumulations of either active factors recruited onto DNA templates or inactive factors stored in the vicinity of genes. According to the latter view, the spatial distribution of genes during interphase should play a major role in the subnuclear organization of nonchromatin components such as replication, transcription, and processing factors, and in this article we discuss current ideas on the functional compartmentalization of chromosomes and genes within the nucleus.
authors.affiliation: Institute of Histology and Embryology, University of Lisbon, Lisboa Codex, 1699, Portugal. hcarmo@skull.cc.fc.ul.pt
authors.forename: M
authors.initials: M
authors.lastname: Carmo-Fonseca
authors.forename: C
authors.initials: C
authors.lastname: Cunha
authors.forename: N
authors.initials: N
authors.lastname: Custódio
authors.forename: C
authors.initials: C
authors.lastname: Carvalho
authors.forename: P
authors.initials: P
authors.lastname: Jordan
authors.forename: J
authors.initials: J
authors.lastname: Ferreira
authors.forename: L
authors.initials: L
authors.lastname: Parreira
mesh_terms: D001665:Binding Sites; D002451:Cell Compartmentation; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure*; D002877:Chromosomes, Human / Q000235:genetics* / Q000648:ultrastructure*; D006367:HeLa Cells; D006801:Humans; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014544:Uridine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D012335:RNA, Ribosomal; D014157:Transcription Factors; C018009:5-bromouridine triphosphate; D012313:RNA; D014544:Uridine Triphosphate