Functions of the MRE11 complex in the development and maintenance of oocytes

• Published in: Chromosoma Vol. 125; no. 1; pp. 151 - 162
• Main Authors: Inagaki, Akiko, Roset, Ramon, Petrini, John H. J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2016; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Animals; Biochemistry; Biomedical and Life Sciences; Cell Biology; Chromosome Pairing; Developmental Biology; DNA - metabolism; DNA Breaks, Double-Stranded; DNA Repair; DNA Repair Enzymes - genetics; DNA Repair Enzymes - metabolism; DNA Repair Enzymes - physiology; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; DNA-Binding Proteins - physiology; Eukaryotic Microbiology; Female; Human Genetics; Life Sciences; Meiosis; Mice; Mice, Transgenic; MRE11 Homologue Protein; Oocytes - metabolism; Oogenesis; Oogonia - metabolism; Oogonia - physiology; Original; Original Article; Female Meiosis; Meiotic Prophase; Primordial Follicle; MLH1 Focus; Synaptonemal Complex
• ISSN: 0009-5915; 1432-0886
• DOI: 10.1007/s00412-015-0535-8

The MRE11 complex (MRE11, RAD50, and NBS1) is a central component of the DNA damage response, governing both double-strand break repair and DNA damage response signaling. To determine the functions of the MRE11 complex in the development and maintenance of oocytes, we analyzed ovarian phenotypes of mice harboring the hypomorphic Mre11 ᴬᵀᴸᴰ¹ allele. Mre11 ᴬᵀᴸᴰ¹/ᴬᵀᴸᴰ¹ females exhibited premature oocyte elimination attributable to defects in homologous chromosome pairing and double-strand break repair during meiotic prophase. Other aspects of meiotic progression, including attachment of telomeres to the nuclear envelope and recruitment of RAD21L, a component of the meiotic cohesin complex to the synaptonemal complex, were normal. Unlike Dmc1 ⁻/⁻ and Trp13 ᴳᵗ/ᴳᵗ mice which exhibit comparable defects in double-strand break repair and oocyte depletion by 5 days post-partum, we found that oocyte attrition occurred by 12 weeks in Mre11 ᴬᵀᴸᴰ¹/ᴬᵀᴸᴰ¹ . Disruption of the oocyte checkpoint pathway governed by Chk2 gene further enhanced the survival of Mre11 ᴬᵀᴸᴰ¹/ᴬᵀᴸᴰ¹ follicles. Together our data suggest that the MRE11 complex influences the elimination of oocytes with unrepaired meiotic double-strand breaks post-natally, in addition to its previously described role in double-strand break repair and homologous synapsis during female meiosis.