Instability of alien chromosome introgressions in wheat associated with improper positioning in the nucleus

0505110 - ÚEB 2020 RIV CH eng J - Journal Article
Perničková, Kateřina - Koláčková, Veronika - Lukaszewski, A.J. - Fan, C. - Vrána, Jan - Duchoslav, M. - Jenkins, G. - Phillips, D. H. - Šamajová, O. - Sedlářová, M. - Šamaj, J. - Doležel, Jaroslav - Kopecký, David
Instability of alien chromosome introgressions in wheat associated with improper positioning in the nucleus.
International Journal of Molecular Sciences. Roč. 20, č. 6 (2019), č. článku 1448. E-ISSN 1422-0067
R&D Projects: GA ČR(CZ) GA17-13853S; GA MŠMT(CZ) EF16_019/0000827
Institutional support: RVO:61389030
Keywords : 3d-fish * Chromatin * Genome stability * Hybrid * Introgression * Nucleus * Rye * Wheat
OECD category: Biochemistry and molecular biology
Impact factor: 4.556, year: 2019
Method of publishing: Open access
http://doi.org/10.3390/ijms20061448

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.
Permanent Link: http://hdl.handle.net/11104/0296628