Defects in meiotic chromosome segregation lead to unreduced male gametes in Arabidopsis SMC5/6 complex mutants

0552129 - ÚEB 2022 RIV US eng J - Journal Article
Yang, Fen - Fernández-Jiménez, N. - Tučková, Martina - Vrána, Jan - Cápal, Petr - Díaz, M. - Pradillo, M. - Pečinka, Aleš
Defects in meiotic chromosome segregation lead to unreduced male gametes in Arabidopsis SMC5/6 complex mutants.
Plant Cell. Roč. 33, č. 9 (2021), s. 3104-3119. ISSN 1040-4651. E-ISSN 1532-298X
R&D Projects: GA ČR(CZ) GA19-13848S; GA MŠMT(CZ) LTC18026; GA MŠMT(CZ) EF16_019/0000827
Institutional support: RVO:61389030
Keywords : DNA-DAMAGE * HOMOLOGOUS RECOMBINATION * PROTEIN
OECD category: Cell biology
Impact factor: 12.085, year: 2021
Method of publishing: Open access
http://doi.org/10.1093/plcell/koab178

Structural maintenance of chromosome 5/6 (SMC5/6) complex is a crucial factor for preserving genome stability. Here, we show that mutants for several Arabidopsis (Arabidopsis thaliana) SMC5/6 complex subunits produce triploid offspring. This phenotype is caused by a meiotic defect leading to the production of unreduced male gametes. The SMC5/6 complex mutants show an absence of chromosome segregation during the first and/or the second meiotic division, as well as a partially disorganized microtubule network. Importantly, although the SMC5/6 complex is partly required for the repair of SPO11-induced DNA double-strand breaks, the nonreduction described here is SPO11-independent. The measured high rate of ovule abortion suggests that, if produced, such defects are maternally lethal. Upon fertilization with an unreduced pollen, the unbalanced maternal and paternal genome dosage in the endosperm most likely causes seed abortion observed in several SMC5/6 complex mutants. In conclusion, we describe the function of the SMC5/6 complex in the maintenance of gametophytic ploidy in Arabidopsis.
Permanent Link: http://hdl.handle.net/11104/0327286