Similar rye A and B chromosome organization in mer

Authors: Veit Schubert Armin Meister Hisashi Tsujimoto Takashi Ryu Endo Andreas Houben

Publish Date: 2011/06/15

Volume: 19, Issue: 5, Pages: 645-655

PDF Link

Abstract

Supernumerary B chromosomes of rye are not required for plant development and exhibit a reduced transcription activity These special features inspired us to analyse whether there are differences between A and B chromatin organization in interphase nuclei Applying fluorescence in situ hybridization we found that both rye A and B chromosomes added to hexaploid wheat showed in meristematic nuclei a stringlike shape and a clear Rabl orientation In 4C differentiated leaf nuclei a more relaxed chromatin structure roundshaped chromosome territories and a less pronounced Rabl configuration were found Also the observed random association of homologues in 2C and 4C nuclei indicated in general a similar behaviour of A and B chromosomes Whereas in differentiated 4C nuclei A sister centromeres are separated B sister centromeres align in nearly all nuclei In short despite the different transcription activity of A and B chromosomes both types of chromosomes exhibit a similar organization in meristematic and differentiated interphase nuclei But the deletion of a B chromosome segment responsible for nondisjunction during gametogenesis induces released sister centromeres also in some interphase nuclei of somatic tissue Hence the control of rye B chromosome nondisjunction is also active in sporophytic cellsWe thank Steve Reader for providing seeds Katrin Kumke for excellent technical assistance Jörg Fuchs for sorting of nuclei and Ingo Schubert for critical reading of the manuscript This work was supported by the Deutsche Forschungsgemeinschaft HO 1779/101

Keywords: