CDK2 is required for proper homologous pairing, recombination and sex-body formation during male mouse meiosis.
Cyclin-dependent kinase 2 (CDK2) was assumed to be essential in the mammalian cell cycle both at the G1-S transition and throughout the S phase. Interestingly, ablation of Cdk2 in mice does not have substantial consequences for embryonic or postnatal development, but both males and females are infertile. In the present study, we have analysed the meiotic alterations leading to infertility in Cdk2-/- male mice. We have studied the distribution and dynamics of several proteins related to meiosis progression, such as synaptonemal complex proteins, cohesin complexes, and centromere-, telomere- and recombination-related proteins. Cdk2-/- spermatocytes show an incomplete chromosome pairing, an extensive non-homologous synapsis and arrest at a pachytene-like stage with unrepaired programmed double-strand breaks. In these spermatocytes, some telomeres do not attach to the nuclear envelope, and sex chromosomes do not form a sex body. Our data demonstrate an unpredicted participation of CDK2 in the accurate pairing and recombination between homologues during mammalian meiosis.
Viera
Alberto
A
Unidad de Biología Celular, Departamento de Biología, Edificio de Ciencias Biológicas, Facultad de Ciencias, Universidad Autónoma de Madrid, Calle Darwin 2, 28049 Madrid, Spain.
Rufas
Julio S
JS
Martínez
Inés
I
Barbero
José L
JL
Ortega
Sagrario
S
Suja
José A
JA
D000818:Animals; D002453:Cell Cycle / Q000235:genetics; D023902:Chromosome Pairing / Q000235:genetics*; D051357:Cyclin-Dependent Kinase 2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D053903:DNA Breaks, Double-Stranded; D008297:Male; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011995:Recombination, Genetic / Q000235:genetics*; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D013091:Spermatogenesis / Q000235:genetics
C495893:Cdk2 protein, mouse; D051357:Cyclin-Dependent Kinase 2