University of Dundee

'Actin protects mammalian eggs against chromosome segregation errors'

Event Date: 
Tuesday, September 26, 2017 - 12:00 to 13:00
Event Location: 
MSI Small Lecture Theatre
Professor Tomo Tanaka FRSE
Event Speaker: 
Dr. Binyam Mogessie
Max Planck Institute for Biophysical Chemistry, Germany
Event Type: 



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.