The nucleus is extensively studied for its role in gene expression. However, growing evidences indicate that the biophysical properties of this organelle participate in cellular functions such as cell migration and pathogen killing; two processes critical for immune response. In this talk, I will describe our discovery of how immune cells undergoing confined migration squeeze their nuclei through narrow pores by forming a dense perinuclear actin network.

Each animal contains a rich diversity and lineage of cell types, equal in complexity to the diversity of animal species themselves. However, much less is known about the origins of cell type. Dr. Phil Abitua, who has done his graduate research with Mike Levine (UCB) and postdoc research with Alex Schier (Harvard), will speak on his work to reconstruct the evolutionary origins of two important vertebrate-specific cell types: neurogenic placodes and neural crest cells.

How simple tissues give rise to geometrically complex organs with robust shapes and functions is a fundamental question in biology with important implications in disease and translational medicine. The current mechanistic framework explains how upstream genetic and biochemical information pattern cellular mechanics and thereby tissue dynamics. In this framework, the main driving force is cell-intrinsic and generated by actomyosin contractility.

Force generation by actin assembly shapes cellular membranes. The mechanisms that govern the organization of cytoskeletal complexes to produce directional force in cells are not understood, particularly in the localized membrane deformations required for membrane trafficking. An experimentally constrained multiscale model shows that a minimal branched actin network is sufficient to internalize endocytic pits against membrane tension. Around 200 activated Arp2/3 complexes are required for robust internalization.

The long-term goal of the Kucenas Lab is to fundamentally understand the cellular and molecular mechanisms that mediate neural-glial and glial-glial interactions during nervous system development and injury/regeneration. Using Danio rerio (zebrafish) as a model system, we combine genetic and pharmacological perturbation, single cell manipulation, laser ablation/axotomy, small molecule screening, and in vivo, time-lapse imaging to directly and continuously observe glial cell origins, behaviors, and interactions in an intact vertebrate.

Population variation within Western Fence Lizards in the Puget Sound
By: Hayden Davis (Leaché Lab)

The role physical asymmetry plays in Drosophila neural stem cells
By: Melissa Delgado (Cabernard Lab)