  The cell nucleus is enveloped by a complex membrane, whose wrinkling has been
implicated in disease and cellular aging. The biophysical dynamics and spectral
evolution of nuclear wrinkling during multicellular development remain poorly
understood due to a lack of direct quantitative measurements. Here, we combine
live-imaging experiments, theory, and simulations to characterize the onset and
dynamics of nuclear wrinkling during egg development in the fruit fly,
Drosophila melanogaster, when nurse cell nuclei increase in size and display
stereotypical wrinkling behavior. A spectral analysis of three-dimensional
high-resolution data from several hundred nuclei reveals a robust asymptotic
power-law scaling of angular fluctuations consistent with renormalization and
scaling predictions from a nonlinear elastic shell model. We further
demonstrate that nuclear wrinkling can be reversed through osmotic shock and
suppressed by microtubule disruption, providing tunable physical and biological
control parameters for probing mechanical properties of the nuclear envelope.
Our findings advance the biophysical understanding of nuclear membrane
fluctuations during early multicellular development.
