Arabidopsis CHROMOSOME TRANSMISSION FIDELITY 7 (AtCTF7/ECO1) is required for DNA repair, mitosis and meiosis.
Bottom Line: No significant change was observed in the expression of genes that influence entry into the endocycle.Analysis of meiocytes identified changes in chromosome morphology and defective segregation; the abundance of chromosomal-bound cohesion subunits was also reduced.Taken together our results demonstrate that Arabidopsis CTF7/ECO1 plays important roles in the preservation of genome integrity and meiosis.
Affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan.Show MeSH
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Mentions: In addition to its critical role in the establishment of sister chromatid cohesion during DNA replication, CTF7/ECO1 may be involved in DNA repair and cell cycle progression (Lu et al., 2010; Lyons and Morgan, 2011). We therefore investigated the effect of the ctf7-1 mutation on the expression of a number of genes required for DNA repair and cell cycle progression. A pathway analysis using AraNet (Lee et al., 2010) suggested a strong functional linkage for these genes (P = 1.054 × 10−82). The relative expression levels of the selected genes were measured in triplicate through QPCR. As shown in Figure 5, large and statistically significant increases (greater than four-fold) in transcript levels were observed for several genes in ctf7-1 plants, including: ATM (a kinase), BRCA1 (a ubiquitin ligase), PARP2 (a polymerase), RAD51 (a gene involved in homology-dependent DNA repair), CYCB1;1 (a G2/M checkpoint gene) and TOPOII-α (a topoisomerase) (Xie and Lam, 1994; Garcia et al., 2003; Preuss and Britt, 2003; Takahashi et al., 2010; Thomson and Guerra-Rebollo, 2010). Smaller increases (approximately two-fold) were observed for SMC5, SMC6B and SRS2 (a helicase) (Ira et al., 2003; Watanabe et al., 2009), while no significant change was observed for ATR (a kinase involved in single-strand break repair) (Yoshiyama et al., 2009), the M-phase checkpoint genes MAD2 and NQK1 (Takahashi et al., 2010) and the gene CDKA1, which regulates the transition from mitosis to endocycle (Dissmeyer et al., 2007). Expression of other topoisomerases was not detected in either WT or ctf7-1 samples, including TOPOI-α, and TOPOI-β (Takahashi et al., 2002).
Affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan.