Bi-orientation of achiasmatic chromosomes in meiosis I oocytes contributes to aneuploidy in mice.
The spindle assembly checkpoint guards against chromosomal missegregation but does not induce arrest in oocytes that contain a few achiasmatic chromosomes (univalents). We followed the fate of univalents in oocytes during the first meiotic division, and although these preserved a meiotic kinetochore structure, they were also bi-oriented in a mitotic manner. The hybrid chromosomal configuration attained by univalents allows them to evade the spindle assembly checkpoint and contribute to aneuploidy in oocytes.
Kouznetsova
Anna
A
Department of Cell and Molecular Biology, Karolinska Institutet, S-171 77, Stockholm, Sweden.
Lister
Lisa
L
Nordenskjöld
Magnus
M
Herbert
Mary
M
Höög
Christer
C
D000782:Aneuploidy; D000818:Animals; D033481:Chromosomes, Mammalian / Q000378:metabolism*; D006801:Humans; D008540:Meiosis; D051379:Mice; D009865:Oocytes / Q000166:cytology*