Altered expression of Aurora kinases in Arabidopsis results in aneu‐ and polyploidization

Abstract

SUMMARYAurora is an evolutionary conserved protein kinase family involved in monitoring of chromosome segregation via phosphorylation of different substrates. In plants, however, the involvement of Aurora proteins in meiosis and in sensing microtubule attachment remains to be proven, although the downstream components leading to the targeting of spindle assembly checkpoint signals to anaphase-promoting complex have been described. To analyze the three members of Aurora family (AtAurora1, -2, and -3) of Arabidopsis we employed different combinations of T-DNA insertion mutants and/or RNAi transformants. Meiotic defects and the formation of unreduced pollen were revealed including plants with an increased ploidy level. The effect of reduced expression of Aurora was mimicked by application of the ATP-competitive Aurora inhibitor II. In addition, strong overexpression of any member of the AtAurora family is not possible. Only tagged or truncated forms of Aurora kinases can be overexpressed. Expression of truncated AtAurora1 resulted in a high number of aneuploids in Arabidopsis, while expression of AtAurora1-TAPi construct in tobacco resulted in 4C (possible tetraploid) progeny. In conclusion, our data demonstrate an essential role of Aurora kinases in the monitoring of meiosis in plants.

Impedance Flow Cytometry: A Novel Technique in Pollen Analysis

“…Analysing plant cells and in particular the quality of pollen in an efficient and reliable manner is not only of interest of plant breeding and seed production industries, but plays also a role in scientific projects investigating pollen development [30,50], pollen-related heat or cold tolerance [22,23], male-sterility systems [51], the establishment of pollen storage or doubled haploid protocols [13,14]. The most critical argument against all methods analysing pollen viability is the missing relevance for pollen germination [39].…”

Arabidopsis Cell Division Cycle 20.1 Is Required for Normal Meiotic Spindle Assembly and Chromosome Segregation

“…Due to functional redundancy, single mutants have normal cell division, whereas the double mutants are either lethal or severely defective in mitosis (Van Damme et al, 2011;Demidov et al, 2014). A recent study provided evidence that the reduced expression of Aurora results in a defect in meiotic chromosome segregation (Demidov et al, 2014).…”

“…Active Aurora B then phosphorylates Ser-10 of histone H3 (H3S10ph), which affects chromosome condensation and segregation (Yamagishi et al, 2010;Castellano-Pozo et al, 2013). A recent study reported that a mutation in the Arabidopsis thaliana Aurora1 gene results in a defect in meiotic chromosome segregation (Demidov et al, 2014), but the cellular defects of the aberrant meiosis were not described in detail.…”

“…By contrast, only a few SAC proteins have been found to be involved in plant meiosis, including the Arabidopsis MPS1 and Aurora kinases (Jiang et al, 2009;Demidov et al, 2014) and the rice (Oryza sativa) Bub1-Related Kinase (BRK1; M. . CDC20 is a cofactor for both SAC and APC/C and has multiple roles in meiotic chromosome segregation in mice, Drosophila melanogaster, and bovine oocytes (Chu et al, 2001;Jin et al, 2010;Sun and Kim, 2012;Yang et al, 2014); however, the role of CDC20 in plant meiosis is unclear.…”

Phosphorylation of MAP65-1 by Arabidopsis Aurora Kinases Is Required for Efficient Cell Cycle Progression

“…Aurora kinases exert multiple roles in diverse cell cycle-related processes by phosphorylating a wide variety of substrates (Biggins and Murray, 2001;Carmena et al, 2009;Fu et al, 2009;Hans et al, 2009;Van Damme et al, 2011;Petrovská et al, 2012;Hochegger et al, 2013;Demidov et al, 2014;Goldenson and Crispino, 2015;Weimer et al, 2015). However, to date, only histone H3 (Hsu et al, 2000) and TPX2 have been reported as alpha Aurora substrates in plants (Demidov et al, 2005;Tomaštíková et al, 2015).…”