XinXin Du, Ph.D., Associate Research Scientist – Biophysical Modeling
Global, Mechanically Coordinated States Arising from Linked, Interacting Cytoskeletal Domains: In multicellular biophysical systems, cells are mechanically linked by adhesion molecules such as E-cadherin. These molecules couple cells’ internal dynamics by directly coupling together their cytoskeletal assemblies; they are also known to contribute to the overall mechanics of multicellular systems. Even though adhesion molecules interact directly with the internal structures of adjacent cells, many existing multicellular models do not capture this. To understand how multicellular systems coordinate at the tissue level and how forces propagate between cells, we present a model of cell-cell coupling that takes into explicit account the dynamics of adhesion molecules and their mechanical interaction with the cytoskeleton. We describe a framework that solves a kinetic problem on the boundaries between cells, ultimately describing cellular adhesions as a dynamic one-dimensional field that interacts with the two-dimensional, cytoskeletal fields internal to the cells. In collectives of cells coupled this way, we find global patterns of polarization as well as formation of spontaneous cortical actin rings that are reminiscent of biological structures. We additionally find more exotic collective states such as alternating polarization, transient stress chains, and oscillatory states. Finally, this framework is generalizable to two-dimensional surfaces of E-cadherin adhesion between cell surfaces as well as integrin coupling between the one cell surface and a substrate.
Natalie Sauerwald, Ph.D., Associate Research Scientist – Genomics
Exploring the Genetic Basis of Sex Differences in Autism: Autism is diagnosed far more frequently in males than in females, yet the biological basis for this disparity remains unclear. In this talk, I’ll present some of our recent work that identified four distinct phenotypic subclasses of autism and their associated genetic architectures. By stratifying individuals within these subclasses, we will further investigate whether sex differences in genetic patterns persist after accounting for phenotypic variability. This approach allows us to disentangle biological sex effects from phenotype-driven heterogeneity, offering new insight into whether the observed sex bias in ASD has a distinct genetic underpinning.