title: A three-dimensional view of precursor messenger RNA metabolism within the mammalian nucleus.
abstract: A quantitative three-dimensional analysis of nuclear components involved in precursor messenger RNA metabolism was performed with a combination of fluorescence hybridization, immunofluorescence, and digital imaging microscopy. Polyadenylate [poly(A)] RNA-rich transcript domains were discrete, internal nuclear regions that formed a ventrally positioned horizontal array in monolayer cells. A dimmer, sometimes strand-like, poly(A) RNA signal was dispersed throughout the nucleoplasm. Spliceosome assembly factor SC-35 localized within the center of individual domains. These data support a nuclear model in which there is a specific topological arrangement of noncontiguous centers involved in precursor messenger RNA metabolism, from which RNA transport toward the nuclear envelope radiates.
authors.affiliation: Department of Cell Biology, University of Massachusetts Medical Center,Worcester 01655.
authors.forename: K C
authors.initials: KC
authors.lastname: Carter
authors.forename: D
authors.initials: D
authors.lastname: Bowman
authors.forename: W
authors.initials: W
authors.lastname: Carrington
authors.forename: K
authors.initials: K
authors.lastname: Fogarty
authors.forename: J A
authors.initials: JA
authors.lastname: McNeil
authors.forename: F S
authors.initials: FS
authors.lastname: Fay
authors.forename: J B
authors.initials: JB
authors.lastname: Lawrence
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism*; D006801:Humans; D008856:Microscopy, Fluorescence; D009685:Nuclear Envelope / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D011061:Poly A / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism
chemical_list: D009687:Nuclear Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D017411:Ribonucleoproteins, Small Nuclear; D011061:Poly A