Sadie Wignall


Ph.D., University of California, Berkeley

Interdisciplinary Biological Sciences Program
Molecular Biosciences

Office Phone: 847.467.0386
Email
Wignall Lab

Research

Proper segregation of chromosomes during mitosis and meiosis depends upon the formation of a bipolar spindle. In most cell types, duplicated centrosomes contribute to spindle assembly by nucleating microtubules and helping to organize the two poles. However, during meiosis in female animals the centrosomes are degraded prior to the meiotic divisions, and therefore oocyte spindles form in their absence. We are interested in understanding how these acentrosomal spindles form, how they are organized, and how they promote proper chromosome partitioning. To address these questions, we combine high-resolution microscopy with genetic, genomic, biochemical, and biophysical approaches in the nematode C. elegans.

These studies are important since errors in meiotic chromosome segregation result in aneuploidy, a leading cause of miscarriages and birth defects in humans. Female meiosis in particular is highly error prone and this vulnerability has a profound impact on human health; it is estimated that as many as 10-25% of human embryos are chromosomally abnormal, and the vast majority of these defects arise from problems with the oocytes. Our research will yield a better molecular understanding of the mechanisms that promote accurate chromosome segregation during oocyte meiosis, which will shed light on how genomic integrity is maintained during the meiotic divisions.

Selected Publications

  1. Mullen TJ and Wignall SM. Interplay between microtubule bundling and sorting factors ensures acentriolar spindle stability during C. elegans oocyte meiosis. PLoS Genetics. 2017 September 14; 13(e):e1006986.
  2. Davis-Roca AC, Muscar CC, and Wignal SM. Caenorhabditis elegans oocytes detect meiotic errors in the absence of canonical end-on kinetochore attachments. Journal of Cell Biology. 2017 May 1; 216(5):1243-1253.
  3. Menodza AD, Woodruff TK, Wignall SM, and O'Halloran TV. Zinc availability during germline development impacts embryo viability in Caenorhabditis elegans. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology. 2017 January; 191:194-202.
  4. Wolff ID, Tran MV, Mullen TJ, Villeneuve AM, and Wignall SM. Assembly of Caenorhabditis elegans acentrosomal spindles occurs without evident microtubule-organizing centers and requires microtubule sorting by KLP-18/kinesin-12 and MESP-1. Molecular Biology of the Cell. 2016 October 15; 27(20):3122-3131.
  5. Muscat CC, Torre-Santiago KM, Tran MV, Powers JA, and Wignall SM. Kinetochore-independent chromosome segregation driven by lateral microtubule bundles. eLife. 2015 May 30; 4:e06462.
  6. Wignall SM and Villeneuve AM. Lateral microtubule bundles promote chromosome alignment during acentrosomal oocyte meiosis. Nature Cell Biology. 2009 July; 11(7):839-844.

 

 

Recent Photos

October 5, 2017