Seminar details

September 26, 2017, 12:00 pm @ Small Lecture Theatre

Dr Binyam Mogessie

Host: Tomoyuki Tanaka

Abstract

Binyam Mogessie and Melina Schuh
Department of Meiosis, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11,
37077 Göttingen, Germany

Chromosome segregation is driven by a spindle that is made of microtubules, but is
generally thought to be independent of actin. Here, we report an unexpected actindependent
mechanism that drives the accurate alignment and segregation of
chromosomes in mammalian eggs. Prominent actin filaments permeated the microtubule
spindle in eggs of several mammalian species, including humans. Disrupting actin in
mouse eggs led to significantly increased numbers of misaligned chromosomes as well
as lagging chromosomes during meiosis I and II. We found that actin drives accurate
chromosome segregation by promoting the formation of functional kinetochore-fibers, the
microtubule bundles that align and segregate the chromosomes. Thus, actin is essential
to prevent chromosome segregation errors in eggs, which are a leading cause of
miscarriages, infertility and Down Syndrome.