Abstract
Yen1/GEN1 are canonical Holliday junction resolvases that belong to the RAD2/XPG family. In eukaryotes, such as budding yeast, mice, worms, and humans, Yen1/GEN1 work together with Mus81-Mms4/MUS81-EME1 and Slx1-Slx4/SLX1-SLX4 in DNA repair by homologous recombination to maintain genome stability. In plants, the biological function of Yen1/GEN1 remains largely unclear. In this study, we characterized the loss of function mutants of OsGEN1 and OsSEND1, a pair of paralogs of Yen1/GEN1 in rice (Oryza sativa). We first investigated the role of OsGEN1 during meiosis and found a reduction in chiasma frequency by ∼6% in osgen1 mutants, compared to the wild type, suggesting a possible involvement of OsGEN1 in the formation of crossovers. Postmeiosis, OsGEN1 foci were detected in wild-type microspore nuclei, but not in the osgen1 mutant concomitant with an increase in double-strand breaks. Persistent double-strand breaks led to programmed cell death of the male gametes and complete male sterility. In contrast, depletion of OsSEND1 had no effects on plant development and did not enhance osgen1 defects. Our results indicate that OsGEN1 is essential for homologous recombinational DNA repair at two stages of microsporogenesis in rice.
Highlights
Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 20040, China (C.W., Y.H., D.Z., W.L.); Department of Genetics, University of Leicester, Leicester LE1 7RH, United Kingdom (J.D.H.); State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China (P.L.); and School of Agriculture, Food and Wine, University of Adelaide, Urrbrae, South Australia 5064, Australia (D.Z.)
OsGEN1 Is Essential for Rice Pollen Development sensitivity4/Essential meiotic endonuclease1), Slx1Slx4/SLX1-SLX4 (Synthetic lethal of unknown function), and Yen1/GEN1 (Holliday junction resolvase YEN1/Gen endonuclease homolog1) are key structurespecific endonucleases involved in Holliday junctions (HJs) resolution in eukaryotes (Boddy et al, 2001; Schwartz and Heyer, 2011)
We showed that depletion of OsGEN1 leads to an ;6% decrease in chiasmata compared to the wild type, which resembled the small fraction of CO decrease observed in Class II mutants in Arabidopsis (Higgins et al, 2008)
Summary
Yen1/GEN1 are canonical Holliday junction resolvases that belong to the RAD2/XPG family. In eukaryotes, such as budding yeast, mice, worms, and humans, Yen1/GEN1 work together with Mus81-Mms4/MUS81-EME1 and Slx1-Slx4/SLX1-SLX4 in DNA repair by homologous recombination to maintain genome stability. OsGEN1 Is Essential for Rice Pollen Development sensitivity4/Essential meiotic endonuclease1), Slx1Slx4/SLX1-SLX4 (Synthetic lethal of unknown function), and Yen1/GEN1 (Holliday junction resolvase YEN1/Gen endonuclease homolog1) are key structurespecific endonucleases involved in HJ resolution in eukaryotes (Boddy et al, 2001; Schwartz and Heyer, 2011). MUS81-EME1 and SLX1-SLX4 act in the same pathway and cooperatively introduce asymmetric cuts on HJs. The gapped and flapped DNA intermediates generated by the asymmetric incisions require further processing before ligation (Fricke and Brill, 2003; Castor et al, 2013; Wyatt et al, 2013). Yen1/GEN1 were considered to be the canonical HJ resolvases in eukaryotes as they cleave HJs in a manner analogous to that of the Escherichia coli resolvase RuvC (crossover junction endodeoxyribonuclease RuvC; Ip et al, 2008; Rass et al, 2010)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
