Presenter : Maithri Sarangam
Mentor : Kryn Stankunas
Major : Biology
Poster 56
Human heart valves are remarkable structures that open and close billions of time during a lifetime. Like any structure under constant mechanical strain, their shape and molecular composition are finely tuned to maximize efficiency and longevity. The development of these valves must also be finely tuned to produce proper the shape and composition, or dangerous health consequences may arise. We are studying the developmental processes of valve formation. Particularly, we are interested in the role of the BAF chromatin remodel- ing complex. Chromatin refers to the complex of DNA and histone proteins. Cell nuclei contain a series of cylindrical histone com- plexes, around which DNA is wrapped. The structure resembles a single thread wrapped around a series of spools with approximately
2 loops per spool. The BAF complex regulates gene expression by altering nucleosome positioning. We believe the BAF complex is required for the proper development of the aortic and pulmonic valves. We used mouse models and complex mouse genetic techniques to study the role of the BAF complex on mammalian heart valve development. Using a crelox system, we caused a loss of function of the BAF complex by knocking out Brg1, the key ATP-ase required for the complex to function. We then used various staining methods to study the resulting phenotype at different time points during the later stages of development. The results suggest that the BAF complex is required for proper organization of the valve shape and molecular composition.