Speaker
Lene Oddershede
(Niels Bohr Institute)
Description
Early in embryonic development the blastocyst consists of a
mix of two different cell populations, one primed towards
the epiblast which will later develop into the fetus, and
one primed for the endoderm, which will develop into the
amniotic sac. Initially, those two populations are mixed and
later they segregate into the fetus and amniotic sac. Using
embryonic stem cells as a relevant model system, we use
optical tweezers to quantify the physical properties of
those two populations and demonstrate that their
viscoelastic properties are significantly different. By
modeling we also show that the difference in viscoelasticity
in those two cell populations is actually enough to cause a
segregation of the two populations, hence, the biomechanical
properties alone can drive the process. Mechanical forces
and biophysical properties of cells are also vital for the
morphogenesis of organs and embryos. However, how mechanical
force and biophysical properties specifically contribute to
tissue formation is poorly understood, predominantly due to
a lack of tools to measure and quantify biomechanical
parameters deep within living developing organisms without
causing severe physiological damage. Using an adapted
version of optical tweezers, we mechanically probe the
developing gut region deep within living zebrafish and show
that the mechanical properties of developing organs differ
significantly. We hypothesize that these biomechanical
differences serve as a segregation mechanism and might drive
development.
