T HE E FFECT OF THE BAF C HROMATIN R EGULATOR IN H EART V ALVE M ATURATION OF M US M USCULUS Kelsey Ward Kryn Stankunas, P.I. Brynn Simek, Mentor

C ONGENITAL H EART D ISEASE (CHD) Most common type of birth defect 1 in 125 births

E PIGENETICS AND C HROMATIN R EMODELING

V ALVULOGENESIS

Chromatin Remodeling by the BAF Complex Brg1 BAF = Brg1 -Associated Factor Brg1 is the core ATPase subunit Facilitates both activation and repression Regulates chromatin compaction, nucleosome positioning Null alleles are peri- implantation lethal

V ALVULOGENESIS

B RG 1 D ELETION IN ALL E NDOCARDIAL C ELLS IS E MBRYONIC L ETHAL Stankunas, K.

♂ SCL-Cre-ER(T); Brg1F/F ♀ Brg1 F/F Check Plugs Administer Tamoxifen (2x40mg/kg) Harvest embryos Check Plugs Administer Tamoxifen (2x40mg/kg) Harvest embryos Section at 7 microns H&E stain Image sections Section at 7 microns H&E stain Image sections Methodology Preserve in PFA Transfer to PBS Dehydrate to 100% EtOH Replace with xylenes Replace with paraffin and fix in blocks Preserve in PFA Transfer to PBS Dehydrate to 100% EtOH Replace with xylenes Replace with paraffin and fix in blocks Genotype embryos Imaging whole embryos Characterize valve defects and consider new time points and crosses

V ALVULOGENESIS

T AMOXIFEN A DMINISTRATION AT E12.5ADBC

I S B RG 1 A CTUALLY D ELETED ? Pulmonic ValveMitral Valve

H OW Q UICKLY D OES D ELETION O CCUR ?

V ENTRICULAR S EPTAL D EFECTS

H OW E FFICIENT IS D ELETION ?

C ONCLUSIONS AND F UTURE D IRECTIONS Brg1 deletion has no phenotypic effect on later valve maturation. Characterization of Scl-cre line and optimization of Tamoxifen dosage. Earlier Brg1 deletion leads to cushion defects and ventricular defects. Allowance of a longer growth period before harvesting. Describing the molecular and cellular basis for the phenotypes.

A CKNOWLEDGEMENTS Brynn Simek, Mentor Kryn Stankunas, P.I. Stankunas Lab SPUR Alex Andrew Fern Matt Scott