[PDF][PDF] MCM8-and MCM9-deficient mice reveal gametogenesis defects and genome instability due to impaired homologous recombination

M Lutzmann, C Grey, S Traver, O Ganier… - Molecular cell, 2012 - cell.com
M Lutzmann, C Grey, S Traver, O Ganier, A Maya-Mendoza, N Ranisavljevic, F Bernex…
Molecular cell, 2012cell.com
We generated knockout mice for MCM8 and MCM9 and show that deficiency for these
genes impairs homologous recombination (HR)-mediated DNA repair during
gametogenesis and somatic cells cycles. MCM8−/− mice are sterile because spermatocytes
are blocked in meiotic prophase I, and females have only arrested primary follicles and
frequently develop ovarian tumors. MCM9−/− females also are sterile as ovaries are
completely devoid of oocytes. In contrast, MCM9−/− testes produce spermatozoa, albeit in …
Summary
We generated knockout mice for MCM8 and MCM9 and show that deficiency for these genes impairs homologous recombination (HR)-mediated DNA repair during gametogenesis and somatic cells cycles. MCM8−/− mice are sterile because spermatocytes are blocked in meiotic prophase I, and females have only arrested primary follicles and frequently develop ovarian tumors. MCM9−/− females also are sterile as ovaries are completely devoid of oocytes. In contrast, MCM9−/− testes produce spermatozoa, albeit in much reduced quantity. Mcm8−/− and Mcm9−/− embryonic fibroblasts show growth defects and chromosomal damage and cannot overcome a transient inhibition of replication fork progression. In these cells, chromatin recruitment of HR factors like Rad51 and RPA is impaired and HR strongly reduced. We further demonstrate that MCM8 and MCM9 form a complex and that they coregulate their stability. Our work uncovers essential functions of MCM8 and MCM9 in HR-mediated DSB repair during gametogenesis, replication fork maintenance, and DNA repair.
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