caa a22 4500 477090206 CHVBK 20180405111514.0 cr unu---uuuuu 170330e19960301xx s 000 0 ger 10.1007/BF02259701 doi (NATIONALLICENCE)springer-10.1007/BF02259701 Strukturdifferenzierungen in Y-Chromosom von Drosophila hydei [Elektronische Daten] The unique morphology of the Y chromosomal lampbrush loops Threads results from ‘coaxial shells' formed by different satellite-specific subregions within megabase-sized transcripts [Roman Kurek, Peter Trapitz, Hans Bünemann] The results of pulsed-field gel electrophoresis (PFGE) analysis and two-colour transcript fluorescencein situ hybridization (FISH) for the threeThreads-specific DNA satellitesYLII, YLI andrally are in support of long-range clustering of these sequence families within the subterminal region on the long arm of the Y chromosome ofDrosophila hydei. On the basis of the linear arrangement of at least four extended clusters of satellite-specific sequences, the loop morphology of wild-type and several mutantThreads can be explained by assumption of a singleThreads-specific transcription unit comprising about 5.1 Mb of repetitive DNA located between thePseudonucleolus and theNucleolus organizer. Transcription is unidirectional from thePseudonucleolus towards the terminally locatedNucleolus organizer. Transcripts most likelly start in front of or within the 3.2 Mb region ofYLII-related sequences, pass through subsequent blocks of 1.2 and 0.3 Mb ofYLI- andrally-related sequences, respectively, and cease within the region of a smaller block ofYLI-related repeats. The megabase-sized transcripts remain physically linked to the DNA axis and their extended satellite-specific regions from coaxial clouds or shells around the central DNA axis. In this way each cluster of earlier-transcribed sequences generates a cloud or shell on top of the later-transcribed ones. According to this model of ‘satellite-specific coaxial shells' the tube-like morphology and other peculiarities of the Y chromosomal lampbrush loopsThreads can be explained as a result of satellitespecific RNA superstructures and/or formation of extended ribonucleoprotein (RNP) complexes between clusters of satellite-specific transcripts and specific proteins. On the basis of this model the specific morphology of severalThreads mutants can be interpreted as the result of large interstitial or terminal deletions that alter the total length of theThreads-specific transcription unit without exerting other major effects on principal features of the transcription process along theThreads. Rapid Science Publishers, 1996 coaxial transcript shells nationallicence Drosophila hydei cell line KUN-DH-33 nationallicence pulsed-field gel electrophoresis of repetitive DNA nationallicence two-colour transcript fluorescence in situ hybridization nationallicence Y chromosomal lampbrush loops Threads nationallicence Kurek Roman Institute of Genetics, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany aut Trapitz Peter Institute of Genetics, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany aut Bünemann Hans Institute of Genetics, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany aut Chromosome Research Kluwer Academic Publishers 4/2(1996-03-01), 87-102 0967-3849 4:2<87 1996 4 10577 https://doi.org/10.1007/BF02259701 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02259701 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kurek Roman Institute of Genetics, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 700 1- Trapitz Peter Institute of Genetics, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 700 1- Bünemann Hans Institute of Genetics, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 773 0- Chromosome Research Kluwer Academic Publishers 4/2(1996-03-01), 87-102 0967-3849 4:2<87 1996 4 10577 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer