Instability of Alien Chromosome Introgressions in Wheat Associated with Improper Positioning in the Nucleus

Authors Organisations
  • Kateřina Perničková(Author)
    Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31
  • Veronika Koláčková (Author)
    Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31
  • Adam J. Lukaszewski(Author)
    University of California, Riverside
  • Chaolan Fan(Author)
    University of California, Riverside
  • Jan Vrána(Author)
    Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31
  • Martin Duchoslav(Author)
    Palacký University
  • Glyn Jenkins(Author)
  • Dylan Phillips(Author)
  • Olga Šamajová(Author)
    Palacký University
  • Michaela Sedlářová(Author)
    Palacký University
  • Jozef Šamaj(Author)
    Palacký University
  • Jaroslav Doležel(Author)
    Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31
  • David Kopecký(Author)
    Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31
Type Article
Original languageEnglish
Article number1448
JournalInternational Journal of Molecular Sciences
Volume20
Issue number6
DOI
Publication statusPublished - 22 Mar 2019
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Abstract

Alien introgressions introduce beneficial alleles into existing crops and hence, are widely used in plant breeding. Generally, introgressed alien chromosomes show reduced meiotic pairing relative to the host genome, and may be eliminated over generations. Reduced pairing appears to result from a failure of some telomeres of alien chromosomes to incorporate into the leptotene bouquet at the onset of meiosis, thereby preventing chiasmate pairing. In this study, we analysed somatic nuclei of rye introgressions in wheat using 3D-FISH and found that while introgressed rye chromosomes or chromosome arms occupied discrete positions in the Rabl’s orientation similar to chromosomes of the wheat host, their telomeres frequently occupied positions away from the nuclear periphery. The frequencies of such abnormal telomere positioning were similar to the frequencies of out-of-bouquet telomere positioning at leptotene, and of pairing failure at metaphase I. This study indicates that improper positioning of alien chromosomes that leads to reduced pairing is not a strictly meiotic event but rather a consequence of a more systemic problem. Improper positioning in the nuclei probably impacts the ability of introgressed chromosomes to migrate into the telomere bouquet at the onset of meiosis, preventing synapsis and chiasma establishment, and leading to their gradual elimination over generations

Keywords

  • chromatin, 3D-FISH, nucleus, introgression, rye, hybrid, wheat, genome stability