TY - JOUR TI - The asymmetry of female meiosis reduces the frequency of inheritance of unpaired chromosomes AU - Cortes, Daniel B AU - McNally, Karen L AU - Mains, Paul E AU - McNally, Francis J A2 - Hyman, Anthony A VL - 4 PY - 2015 DA - 2015/04/07 SP - e06056 C1 - eLife 2015;4:e06056 DO - 10.7554/eLife.06056 UR - https://doi.org/10.7554/eLife.06056 AB - Trisomy, the presence of a third copy of one chromosome, is deleterious and results in inviable or defective progeny if passed through the germ line. Random segregation of an extra chromosome is predicted to result in a high frequency of trisomic offspring from a trisomic parent. Caenorhabditis elegans with trisomy of the X chromosome, however, have far fewer trisomic offspring than expected. We found that the extra X chromosome was preferentially eliminated during anaphase I of female meiosis. We utilized a mutant with a specific defect in pairing of the X chromosome as a model to investigate the apparent bias against univalent inheritance. First, univalents lagged during anaphase I and their movement was biased toward the cortex and future polar body. Second, late-lagging univalents were frequently captured by the ingressing polar body contractile ring. The asymmetry of female meiosis can thus partially correct pre-existing trisomy. KW - meiosis KW - trisomy KW - polar body JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -